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R J Weesie - One of the best experts on this subject based on the ideXlab platform.
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in α-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of α-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15′, 14,14′, 13,13′, 12,12′, or 20,20′ were recorded. This approach enabled us to obtain information about the effect of the ligand–protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the CC stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250–1400 cm−1 spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in α-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the π-antibonding CO orbitals and the HOMO–LUMO gap. © 1999 John Wiley & Sons, Inc. Biospectroscopy 5: 358–370, 1999
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in alpha-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of alpha-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15', 14,14', 13,13', 12,12', or 20,20' were recorded. This approach enabled us to obtain information about the effect of the ligand-protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the C==C stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250-1400 cm(-1) spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in alpha-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the pi-antibonding C==O orbitals and the HOMO-LUMO gap.
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in α crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, George Britton, J C Merlin, H J M De GrootAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in alpha crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, J C Merlin, George BrittonAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
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protein chromophore interactions in α crustacyanin the major blue carotenoprotein from the carapace of the lobster homarus gammarus a study by 13c magic angle spinning nmr
FEBS Letters, 1995Co-Authors: R J Weesie, D Askin, F J H M Jansen, H J M De Groot, J Lugtenburg, George BrittonAbstract:MAS (magic angle spinning) 13C NMR has been used to study protein-chromophore interactions in α-crustacyanin, the blue Astaxanthin-binding carotenoprotein of the lobster, Homarus gammarus, reconstituted with Astaxanthins labelled with 13C at the 14,14′ or 15,15′ positions. Two signals are seen for α-crustacyanin containing [14,14′-13C2]Astaxanthin, shifted 6.9 and 4.0 ppm downfield from the 134.1 ppm signal of uncomplexed Astaxanthin in the solid state. With α-crustacyanin containing [15,15′-13C2]Astaxanthin, one essentially unshifted broad signal is seen. Hence binding to the protein causes a decrease in electronic charge density, providing the first experimental evidence that a charge redistribution mechanism contributes to the bathochromic shift of the Astaxanthin in α-crustacyanin, in agreement with inferences based on resonance Raman data [Salares, et al. (1979) Biochim. Biophys. Acta 576, 176–191]. The splitting of the 14 and 14′ signals provides evidence for asymmetric binding of each Astaxanthin molecule by the protein.
George Britton - One of the best experts on this subject based on the ideXlab platform.
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in α-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of α-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15′, 14,14′, 13,13′, 12,12′, or 20,20′ were recorded. This approach enabled us to obtain information about the effect of the ligand–protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the CC stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250–1400 cm−1 spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in α-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the π-antibonding CO orbitals and the HOMO–LUMO gap. © 1999 John Wiley & Sons, Inc. Biospectroscopy 5: 358–370, 1999
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in alpha-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of alpha-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15', 14,14', 13,13', 12,12', or 20,20' were recorded. This approach enabled us to obtain information about the effect of the ligand-protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the C==C stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250-1400 cm(-1) spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in alpha-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the pi-antibonding C==O orbitals and the HOMO-LUMO gap.
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in α crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, George Britton, J C Merlin, H J M De GrootAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in alpha crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, J C Merlin, George BrittonAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
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protein chromophore interactions in α crustacyanin the major blue carotenoprotein from the carapace of the lobster homarus gammarus a study by 13c magic angle spinning nmr
FEBS Letters, 1995Co-Authors: R J Weesie, D Askin, F J H M Jansen, H J M De Groot, J Lugtenburg, George BrittonAbstract:MAS (magic angle spinning) 13C NMR has been used to study protein-chromophore interactions in α-crustacyanin, the blue Astaxanthin-binding carotenoprotein of the lobster, Homarus gammarus, reconstituted with Astaxanthins labelled with 13C at the 14,14′ or 15,15′ positions. Two signals are seen for α-crustacyanin containing [14,14′-13C2]Astaxanthin, shifted 6.9 and 4.0 ppm downfield from the 134.1 ppm signal of uncomplexed Astaxanthin in the solid state. With α-crustacyanin containing [15,15′-13C2]Astaxanthin, one essentially unshifted broad signal is seen. Hence binding to the protein causes a decrease in electronic charge density, providing the first experimental evidence that a charge redistribution mechanism contributes to the bathochromic shift of the Astaxanthin in α-crustacyanin, in agreement with inferences based on resonance Raman data [Salares, et al. (1979) Biochim. Biophys. Acta 576, 176–191]. The splitting of the 14 and 14′ signals provides evidence for asymmetric binding of each Astaxanthin molecule by the protein.
Feng Chen - One of the best experts on this subject based on the ideXlab platform.
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two dimensional liquid chromatography analysis of all trans 9 cis and 13 cis Astaxanthin in raw extracts from phaffia rhodozyma
IEEE Journal of Solid-state Circuits, 2020Co-Authors: Chun Wang, Faizan A Sadiq, Zedong Jiang, Feng ChenAbstract:An effective two-dimensional liquid chromatography method has been established for the analysis of all-trans-Astaxanthin and its geometric isomers from Phaffia rhodozyma employing a C18 column at the first dimension and a C30 column in the second dimension, connected by a 10-port valve using the photo-diode array detector. The regression equation of Astaxanthin calibration curve was established, and the precision and accuracy values were found to be in the range of 0.32-1.14% and 98.21-106.13%, respectively. By using two-dimensional liquid chromatography, it was found that day light, ultrasonic treatment, and heat treatment have significant influence on the content of all-trans-Astaxanthin in the extract from P. rhodozyma due to the transformation of all-trans-Astaxanthin to cis-Astaxanthin. The day light and ultrasonic treatments more likely transform all-trans-Astaxanthin to 9-cis-Astaxanthin, and the thermal treatment transforms all-trans-Astaxanthin to 13-cis-Astaxanthin. These results indicate that the two-dimensional liquid chromatography method can facilitate monitoring Astaxanthin isomerization in the raw extract from P. rhodozyma. In addition, the study will provide a general reference for monitoring other medicals and bioactive chemicals with geometric isomers.
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molecular mechanisms of the coordination between Astaxanthin and fatty acid biosynthesis in haematococcus pluvialis chlorophyceae
Plant Journal, 2015Co-Authors: Guanqun Chen, Baobei Wang, Danxiang Han, Milton R Sommerfeld, Feng ChenAbstract:Summary Astaxanthin, a red ketocarotenoid with strong antioxidant activity and high commercial value, possesses important physiological functions in Astaxanthin-producing microalgae. The green microalga Haematococcus pluvialis accumulates up to 4% fatty acid-esterified Astaxanthin (by dry weight), and is used as a model species for exploring Astaxanthin biosynthesis in unicellular photosynthetic organisms. Although coordination of Astaxanthin and fatty acid biosynthesis in a stoichiometric fashion was observed in H. pluvialis, the interaction mechanism is unclear. Here we dissected the molecular mechanism underlying coordination between the two pathways in H. pluvialis. Our results eliminated possible coordination of this inter-dependence at the transcriptional level, and showed that this interaction was feedback-coordinated at the metabolite level. In vivo and in vitro experiments indicated that Astaxanthin esterification drove the formation and accumulation of Astaxanthin. We further showed that both free Astaxanthin biosynthesis and esterification occurred in the endoplasmic reticulum, and that certain diacylglycerol acyltransferases may be the candidate enzymes catalyzing Astaxanthin esterification. A model of Astaxanthin biosynthesis in H. pluvialis was subsequently proposed. These findings provide further insights into Astaxanthin biosynthesis in H. pluvialis.
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utilization of cane molasses towards cost saving Astaxanthin production by a chlorella zofingiensis mutant
Journal of Applied Phycology, 2013Co-Authors: Jin Liu, Zheng Sun, Yujuang Zhong, Henri Gerken, Junchao Huang, Feng ChenAbstract:The aim of the present study was to survey the growth and Astaxanthin production of E17, an Astaxanthin-rich mutant of Chlorella zofingiensis, through feeding the low-cost carbon source cane molasses. In heterotrophic batch cultivation, E17 fed with pretreated molasses achieved biomass (1.79 g L−1 day−1) and Astaxanthin (1.99 mg L−1 day−1) productivities comparable to those with glucose, which were about 2- and 2.8-fold of those fed with untreated molasses, respectively. Molasses-induced Astaxanthin accumulation may be attributed to the elicited expression of carotenogenic genes, in particular the genes specifically responsible for the ketolation and hydroxylation of β-carotene to form Astaxanthin. A two-stage fed-batch strategy was employed to grow E17 and induce astaxathin accumulation, resulting in 45.6 g L−1 biomass and 56.1 mg L−1 Astaxanthin, the highest volumetric Astaxanthin yield ever reported for this alga. In addition, the Astaxanthin production by E17 was tested with a semi-continuous culture method, where the directly diluted raw molasses (giving 5 g L−1 sugar) was used as the carbon source. Little growth inhibition of E17 was observed in the semi-continuous culture with a biomass productivity of 1.33 g L−1 day−1 and an Astaxanthin productivity of 0.83 mg L−1 day−1. The mixotrophic semi-continuous cultures enhanced the biomass and Astaxanthin productivities by 29.3 % and 42.2 %, respectively. This study highlights the potential of using the industrially cheap cane molasses towards large-scale cost-saving production of the high-value ketocarotenoid Astaxanthin.
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functional characterization of various algal carotenoid ketolases reveals that ketolating zeaxanthin efficiently is essential for high production of Astaxanthin in transgenic arabidopsis
Journal of Experimental Botany, 2011Co-Authors: Yujuan Zhong, Feng Chen, Gerhard Sandmann, Jin Liu, Junchao Huang, Yue JiangAbstract:Extending the carotenoid pathway to Astaxanthin in plants is of scientific and industrial interest. However, expression of a microbial b-carotene ketolase (BKT) that catalyses the formation of ketocarotenoids in transgenic plants typically results in low levels of Astaxanthin. The low efficiency of BKTs in ketolating zeaxanthin to Astaxanthin is proposed to be the major limitation for Astaxanthin accumulation in engineered plants. To verify this hypothesis, several algal BKTs were functionally characterized using an Escherichia coli system and three BKTs were identified, with high (up to 85%), moderate (;38%), and low (;1%) conversion rate from zeaxanthin to Astaxanthin from Chlamydomonas reinhardtii (CrBKT), Chlorella zofingiensis (CzBKT), and Haematococcus pluvialis (HpBKT3), respectively. Transgenic Arabidopsis thaliana expressing the CrBKT developed orange leaves which accumulated Astaxanthin up to 2 mg g 21 dry weight with a 1.8-fold increase in total carotenoids. In contrast, the expression of CzBKT resulted in much lower Astaxanthin content (0.24 mg g 21 dry weight), whereas HpBKT3 was unable to mediate synthesis of Astaxanthin in A. thaliana. The none-native Astaxanthin was found mostly in a free form integrated into the light-harvesting complexes of photosystem II in young leaves but in esterified forms in senescent leaves. The alteration of carotenoids did not affect chlorophyll content, plant growth, or development significantly. The Astaxanthin-producing plants were more tolerant to high light as shown by reduced lipid peroxidation. This study advances a decisive step towards the utilization of plants for the production of high-value Astaxanthin.
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Purification of trans-Astaxanthin from a high-yielding Astaxanthin ester-producing strain of the microalga Haematococcus pluvialis
Food Chemistry, 2000Co-Authors: Jian-ping Yuan, Feng ChenAbstract:The purification method including extraction, saponification, and separation was established for preparing free trans-Astaxanthin from a high-yielding Astaxanthin ester-producing strain of the microalga Haematococcus pluvialis which contained 3.67% trans-Astaxanthins and 1.35% cis-Astaxanthins of the dry cells. Low temperature (5°C) was chosen to minimize the degradation of Astaxanthins during saponification, and 94.4% free trans-Astaxanthin was obtained from trans-Astaxanthin esters after 12 h of saponification. With this method, 32.2 mg trans-Astaxanthin was obtained from 1 g dry algal cells. In addition, a new gradient reversed-phase HPLC method, suited for the quick analysis of free Astaxanthins and Astaxanthin esters in the unsaponified and saponified pigment extracts from the high-yielding Astaxanthin ester-producing strain of the microalga Haematococcus pluvialis, was developed and applied to the determination of Astaxanthin contents during the processes of extraction, saponification, and purification.
H J M De Groot - One of the best experts on this subject based on the ideXlab platform.
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spectroscopy and quantum chemical modeling reveal a predominant contribution of excitonic interactions to the bathochromic shift in α crustacyanin the blue carotenoprotein in the carapace of the lobster homarus gammarus
Journal of the American Chemical Society, 2005Co-Authors: Arjan A C Van Wijk, H J M De Groot, J Lugtenburg, Arnold Spaans, N Uzunbajakava, Cees Otto, Francesco BudaAbstract:To resolve the molecular basis of the coloration mechanism of α-crustacyanin, we used 13C-labeled Astaxanthins as chromophores for solid-state 13C NMR and resonance Raman spectroscopy of [6,6‘,7,7‘]-13C4 α-crustacyanin and [8,8‘,9,9‘,10,10‘,11,11‘,20,20‘]-13C10 α-crustacyanin. We complement the experimental data with time-dependent density functional theory calculations on several models based on the structural information available for β-crustacyanin. The data rule out major changes and strong polarization effects in the ground-state electron density of Astaxanthin upon binding to the protein. Conformational changes in the chromophore and hydrogen-bond interactions between the Astaxanthin and the protein can account only for about one-third of the total bathochromic shift in α-crustacyanin. The exciton coupling due to the proximity of two Astaxanthin chromophores is found to be large, suggesting that aggregation effects in the protein represent the primary source of the color change.
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in alpha-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of alpha-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15', 14,14', 13,13', 12,12', or 20,20' were recorded. This approach enabled us to obtain information about the effect of the ligand-protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the C==C stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250-1400 cm(-1) spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in alpha-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the pi-antibonding C==O orbitals and the HOMO-LUMO gap.
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in α-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of α-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15′, 14,14′, 13,13′, 12,12′, or 20,20′ were recorded. This approach enabled us to obtain information about the effect of the ligand–protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the CC stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250–1400 cm−1 spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in α-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the π-antibonding CO orbitals and the HOMO–LUMO gap. © 1999 John Wiley & Sons, Inc. Biospectroscopy 5: 358–370, 1999
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in α crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, George Britton, J C Merlin, H J M De GrootAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
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protein chromophore interactions in α crustacyanin the major blue carotenoprotein from the carapace of the lobster homarus gammarus a study by 13c magic angle spinning nmr
FEBS Letters, 1995Co-Authors: R J Weesie, D Askin, F J H M Jansen, H J M De Groot, J Lugtenburg, George BrittonAbstract:MAS (magic angle spinning) 13C NMR has been used to study protein-chromophore interactions in α-crustacyanin, the blue Astaxanthin-binding carotenoprotein of the lobster, Homarus gammarus, reconstituted with Astaxanthins labelled with 13C at the 14,14′ or 15,15′ positions. Two signals are seen for α-crustacyanin containing [14,14′-13C2]Astaxanthin, shifted 6.9 and 4.0 ppm downfield from the 134.1 ppm signal of uncomplexed Astaxanthin in the solid state. With α-crustacyanin containing [15,15′-13C2]Astaxanthin, one essentially unshifted broad signal is seen. Hence binding to the protein causes a decrease in electronic charge density, providing the first experimental evidence that a charge redistribution mechanism contributes to the bathochromic shift of the Astaxanthin in α-crustacyanin, in agreement with inferences based on resonance Raman data [Salares, et al. (1979) Biochim. Biophys. Acta 576, 176–191]. The splitting of the 14 and 14′ signals provides evidence for asymmetric binding of each Astaxanthin molecule by the protein.
J Lugtenburg - One of the best experts on this subject based on the ideXlab platform.
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spectroscopy and quantum chemical modeling reveal a predominant contribution of excitonic interactions to the bathochromic shift in α crustacyanin the blue carotenoprotein in the carapace of the lobster homarus gammarus
Journal of the American Chemical Society, 2005Co-Authors: Arjan A C Van Wijk, H J M De Groot, J Lugtenburg, Arnold Spaans, N Uzunbajakava, Cees Otto, Francesco BudaAbstract:To resolve the molecular basis of the coloration mechanism of α-crustacyanin, we used 13C-labeled Astaxanthins as chromophores for solid-state 13C NMR and resonance Raman spectroscopy of [6,6‘,7,7‘]-13C4 α-crustacyanin and [8,8‘,9,9‘,10,10‘,11,11‘,20,20‘]-13C10 α-crustacyanin. We complement the experimental data with time-dependent density functional theory calculations on several models based on the structural information available for β-crustacyanin. The data rule out major changes and strong polarization effects in the ground-state electron density of Astaxanthin upon binding to the protein. Conformational changes in the chromophore and hydrogen-bond interactions between the Astaxanthin and the protein can account only for about one-third of the total bathochromic shift in α-crustacyanin. The exciton coupling due to the proximity of two Astaxanthin chromophores is found to be large, suggesting that aggregation effects in the protein represent the primary source of the color change.
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in alpha-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of alpha-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15', 14,14', 13,13', 12,12', or 20,20' were recorded. This approach enabled us to obtain information about the effect of the ligand-protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the C==C stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250-1400 cm(-1) spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in alpha-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the pi-antibonding C==O orbitals and the HOMO-LUMO gap.
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resonance raman spectroscopy and quantum chemical modeling studies of protein Astaxanthin interactions in alpha crustacyanin major blue carotenoprotein complex in carapace of lobster homarus gammarus
Biospectroscopy, 1999Co-Authors: R J Weesie, F J H M Jansen, H J M De Groot, J Lugtenburg, George Britton, J C Merlin, J P CornardAbstract:Resonance Raman spectroscopy and quantum chemical calculations were used to investigate the molecular origin of the large redshift assumed by the electronic absorption spectrum of Astaxanthin in α-crustacyanin, the major blue carotenoprotein from the carapace of the lobster, Homarus gammarus. Resonance Raman spectra of α-crustacyanin reconstituted with specifically 13C-labeled Astaxanthins at the positions 15, 15,15′, 14,14′, 13,13′, 12,12′, or 20,20′ were recorded. This approach enabled us to obtain information about the effect of the ligand–protein interactions on the geometry of the Astaxanthin chromophore in the ground electronic state. The magnitude of the downshifts of the CC stretching modes for each labeled compound indicate that the main perturbation on the central part of the polyene chain is not homogeneous. In addition, changes in the 1250–1400 cm−1 spectral range indicate that the geometry of the Astaxanthin polyene chain is moderately changed upon binding to the protein. Semiempirical quantum chemical modeling studies (Austin method 1) show that the geometry change cannot be solely responsible for the bathochromic shift from 480 to 632 nm of protein-bound Astaxanthin. The calculations are consistent with a polarization mechanism that involves the protonation or another interaction with a positive ionic species of comparable magnitude with both ketofunctionalities of the Astaxanthin-chromophore and support the changes observed in the resonance Raman and visible absorption spectra. The results are in good agreement with the conclusions that were drawn on the basis of a study of the charge densities in the chromophore in α-crustacyanin by solid-state NMR spectroscopy. From the results the dramatic bathochromic shift can be explained not only from a change in the ground electronic state conformation but also from an interaction in the excited electronic state that significantly decreases the energy of the π-antibonding CO orbitals and the HOMO–LUMO gap. © 1999 John Wiley & Sons, Inc. Biospectroscopy 5: 358–370, 1999
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in α crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, George Britton, J C Merlin, H J M De GrootAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
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13c magic angle spinning nmr analysis and quantum chemical modeling of the bathochromic shift of Astaxanthin in alpha crustacyanin the blue carotenoprotein complex in the carapace of the lobster homarus gammarus
Biochemistry, 1997Co-Authors: R J Weesie, F J H M Jansen, J Lugtenburg, J C Merlin, George BrittonAbstract:Selective isotope enrichment, 13C magic angle spinning (MAS) NMR, and semiempirical quantum chemical modeling, have been used to analyze ligand−protein interactions associated with the bathochromic shift of Astaxanthin in α-crustacyanin, the blue carotenoprotein complex from the carapace of the lobster Homarus gammarus. Spectra of α-crustacyanin were obtained after reconstitution with Astaxanthins labeled with 13C at positions 4,4‘, 12,12‘, 13,13‘, or 20,20‘. The data reveal substantial downfield shifts of 4.9 and 7.0 ppm at positions 12 and 12‘ in the complex, respectively. In contrast, at the 13 and 13‘ positions, small upfield shifts of 1.9 ppm were observed upon binding to the protein. These data are in line with previously obtained results for positions 14,14‘ (3.9 and 6.8 ppm downfield) and 15,15‘ (0.6 ppm upfield) and confirm the unequal perturbation of both halves after binding of the chromophore. However, these results also show that the main perturbation is of symmetrical origin, since the chemi...
