The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Kenneth B. Storey - One of the best experts on this subject based on the ideXlab platform.
-
GLYCOLYTIC Enzyme Binding IN OTALA LACTEA HEPATOPANCREAS : EFFECT OF TAXOL, COLCHICINE AND CYTOCHALASIN B AND D ON THE IN VIVO Enzyme DISTRIBUTION
Biochemistry and molecular biology international, 1997Co-Authors: Stephen P. J. Brooks, Kenneth B. StoreyAbstract:The effect of cytoskeleton modulators on glycolytic Enzyme Binding was examined in the hepatopancreas of Otala lactea in an attempt to identify potential cellular Binding sites. Binding was followed by measuring phosphofructokinase (PFK), aldolase (ALD), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and pyruvate kinase (PK) distribution between low speed pellets (12,000 xg), high speed pellets (100,000 xg) and high speed supernatants. Taxol (which stabilizes microtubules), colchicine (which destabilizes microtubules) and cytochalasin B and D (which destabilize F-actin filaments) were added to the homogenate prior to centrifugation. Addition of taxol increased the amount of PFK associated with the high speed pellet. Cytochalasin B and D reduced the Binding of PFK and PK to the low speed pellet. ALD and GAPDH Binding were unaffected by any treatment. Lowering the pH of the crude homogenate increased PFK Binding to the low speed pellet by 33%. This effect could be reversed by addition of cytochalasin B and D suggesting that pH influences the PFK-F-actin interaction in vivo. The differential Binding response of PFK, PK, ALD and GAPDH to added effectors suggests that, in the cell, PFK and PK are bound to different subcellular structural elements than are ALD and GAPDH.
-
Control of glycolytic Enzyme Binding : effect of changing Enzyme substrate concentrations on in vivo Enzyme distributions
Molecular and cellular biochemistry, 1993Co-Authors: Stephen P. J. Brooks, Kenneth B. StoreyAbstract:The effect of changing concentrations of glycolytic intermediates on the Binding of phosphofructokinase, aldolase and pyruvate kinase to cellular particulate matter was investigated. Concentrations of glycolytic intermediates were altered by adding 2 mM iodoacetic acid (IAA) to an incubation medium containing tissues isolated from the channelled whelk Busycon canaliculatum. Iodoacetic acid inhibited glyceraldehyde 3-phosphate dehydrogenase activity causing a 100-400 fold increase in the concentration of fructose 1,6-bisphosphate as well as 3-20 fold increases in glucose 6-phosphate, fructose 6-phosphate, and dihydroxyacetone phosphate levels depending on the experimental protocol. Cellular pH values were not statistically different in the presence of IAA. Measurement of Enzyme Binding to particulate matter showed that the Binding of phosphofructokinase, aldolase and pyruvate kinase was unaffected by iodoacetic acid under any experimental condition. These results show that changes in the tissue concentrations of Enzyme substrates and products do not regulate Enzyme Binding to particulate matter in the cell.
-
Control of glycolytic Enzyme Binding: effect of changing Enzyme substrate concentrations onin vivo Enzyme distributions
Molecular and Cellular Biochemistry, 1993Co-Authors: Stephen P. J. Brooks, Kenneth B. StoreyAbstract:The effect of changing concentrations of glycolytic intermediates on the Binding of phosphofructokinase, aldolase and pyruvate kinase to cellular particulate matter was investigated. Concentrations of glycolytic intermediates were altered by adding 2mM iodoacetic acid (IAA) to an incubation medium containing tissues isolated from the channelled whelk Busycon canaliculatum . Iodoacetic acid inhibited glyceraldehyde 3-phosphate dehydrogenase activity causing a 100–400 fold increase in the concentration of fructose 1,6-bisphosphate as well as 3–20 fold increases in glucose 6-phosphate, fructose 6-phosphate, and dihydroxyacetone phosphate levels depending on the experimental protocol. Cellular pH values were not statistically different in the presence of IAA. Measurement of Enzyme Binding to particulate matter showed that the Binding of phosphofructokinase, aldolase and pyruvate kinase was unaffected by iodoacetic acid under any experimental conditon. These results show that changes in the tissue concentrations of Enzyme substrates and products do not regulate Enzyme Binding to particulate matter in the cell. (Mol Cell Biochem 122 : 1–7, 1993)
-
Subcellular Enzyme Binding and the regulation of glycolysis in anoxic turtle brain
American Journal of Physiology-Regulatory Integrative and Comparative Physiology, 1992Co-Authors: John A. Duncan, Kenneth B. StoreyAbstract:The association of glycolytic Enzymes with the particulate fraction of the cell was assessed in the brain of the freshwater turtle, Pseudemys scripta elegans, using three different methodologies. Each method showed that a large percentage of each of eight Enzymes was bound in brain. The effect of environmental anoxia (5 or 20 h submergence in N2-bubbled water at 7 degrees C) on the distribution of Enzymes between free and bound states was analyzed. All three techniques showed a significant increase in the percentages of brain aldolase and glyceraldehyde-3-phosphate dehydrogenase bound during anoxia and no change in lactate dehydrogenase or creatine kinase Binding. Two methodologies also showed an increase in the percent bound during anoxia for hexokinase, phosphofructokinase, and phosphoglycerate kinase. An increased association of glycolytic Enzymes with structural elements of the cell during anoxia may physically position the glycolytic pathway to facilitate coupling between this ATP-generating pathway and ATP-utilizing processes, such as membrane ion pumps.
-
Role of Enzyme Binding in muscle metabolism of the goldfish
Canadian Journal of Zoology, 1991Co-Authors: John A. Duncan, Kenneth B. StoreyAbstract:Regulation of glycolytic metabolism in muscle by the reversible association of Enzymes with the particulate fraction of the cell was assessed in heart and white skeletal muscle of the goldfish Cara...
B. J. Pearson - One of the best experts on this subject based on the ideXlab platform.
-
Measuring Enzyme Binding using shaped ultrafast laser pulses
EPJ Web of Conferences, 2013Co-Authors: B. J. Pearson, Chien-hung Tseng, T. C. WeinachtAbstract:We use multiphoton quantum-control spectroscopy to discriminate between Enzyme-bound and unbound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbound molecules for different pulse shapes allows us to measure Binding without spectrally resolving the emitted fluorescence or relying on the absolute fluorescence yield. This permits determination of Enzyme Binding in situations where spectrally resolved measurements and absolute fluorescence yields are difficult to obtain, and makes the approach ideal for multiphoton microscopy with molecular discrimination.
-
Using shaped ultrafast laser pulses to detect Enzyme Binding.
Optics express, 2011Co-Authors: Chien-hung Tseng, T. C. Weinacht, Anna E. Rhoades, Matthew Murray, B. J. PearsonAbstract:We use multiphoton quantum-control spectroscopy to discriminate between unbound and Enzyme-bound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbound molecules for different pulse shapes allows us to measure Binding without spectrally resolving the emitted fluorescence or relying on the absolute fluorescence yield. This permits determination of Enzyme Binding in situations where spectrally resolved measurements and absolute fluorescence yields are difficult to obtain, and makes the approach ideal for multiphoton microscopy with molecular discrimination.
Chien-hung Tseng - One of the best experts on this subject based on the ideXlab platform.
-
Measuring Enzyme Binding using shaped ultrafast laser pulses
EPJ Web of Conferences, 2013Co-Authors: B. J. Pearson, Chien-hung Tseng, T. C. WeinachtAbstract:We use multiphoton quantum-control spectroscopy to discriminate between Enzyme-bound and unbound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbound molecules for different pulse shapes allows us to measure Binding without spectrally resolving the emitted fluorescence or relying on the absolute fluorescence yield. This permits determination of Enzyme Binding in situations where spectrally resolved measurements and absolute fluorescence yields are difficult to obtain, and makes the approach ideal for multiphoton microscopy with molecular discrimination.
-
Using shaped ultrafast laser pulses to detect Enzyme Binding.
Optics express, 2011Co-Authors: Chien-hung Tseng, T. C. Weinacht, Anna E. Rhoades, Matthew Murray, B. J. PearsonAbstract:We use multiphoton quantum-control spectroscopy to discriminate between unbound and Enzyme-bound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbound molecules for different pulse shapes allows us to measure Binding without spectrally resolving the emitted fluorescence or relying on the absolute fluorescence yield. This permits determination of Enzyme Binding in situations where spectrally resolved measurements and absolute fluorescence yields are difficult to obtain, and makes the approach ideal for multiphoton microscopy with molecular discrimination.
T. C. Weinacht - One of the best experts on this subject based on the ideXlab platform.
-
Measuring Enzyme Binding using shaped ultrafast laser pulses
EPJ Web of Conferences, 2013Co-Authors: B. J. Pearson, Chien-hung Tseng, T. C. WeinachtAbstract:We use multiphoton quantum-control spectroscopy to discriminate between Enzyme-bound and unbound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbound molecules for different pulse shapes allows us to measure Binding without spectrally resolving the emitted fluorescence or relying on the absolute fluorescence yield. This permits determination of Enzyme Binding in situations where spectrally resolved measurements and absolute fluorescence yields are difficult to obtain, and makes the approach ideal for multiphoton microscopy with molecular discrimination.
-
Using shaped ultrafast laser pulses to detect Enzyme Binding.
Optics express, 2011Co-Authors: Chien-hung Tseng, T. C. Weinacht, Anna E. Rhoades, Matthew Murray, B. J. PearsonAbstract:We use multiphoton quantum-control spectroscopy to discriminate between unbound and Enzyme-bound NADH (reduced nicotinamide adenine dinucleotide) molecules in solution. Shaped ultrafast laser pulses are used to illuminate both forms of NADH, and the ratio of the fluorescence from the bound and unbound molecules for different pulse shapes allows us to measure Binding without spectrally resolving the emitted fluorescence or relying on the absolute fluorescence yield. This permits determination of Enzyme Binding in situations where spectrally resolved measurements and absolute fluorescence yields are difficult to obtain, and makes the approach ideal for multiphoton microscopy with molecular discrimination.
Orlando J. Rojas - One of the best experts on this subject based on the ideXlab platform.
-
Lignin Films from Spruce, Eucalyptus, and Wheat Straw Studied with Electroacoustic and Optical Sensors: Effect of Composition and Electrostatic Screening on Enzyme Binding
Biomacromolecules, 2017Co-Authors: Antonio Pereira, Ingrid C. Hoeger, Ana Ferrer, Jorge Rencoret, José C. Del Rio, Kristiina Kruus, Jenni Rahikainen, Miriam Kellock, Ana Gutiérrez, Orlando J. RojasAbstract:Lignins were isolated from spruce, wheat straw, and eucalyptus by using the milled wood lignin (MWL) method. Functional groups and compositional analyses were assessed via 2D NMR and 31P NMR to realize their effect on Enzyme Binding. Films of the lignins were fabricated and ellipsometry, atomic force microscopy, and water contact angle measurements were used for their characterization and to reveal the changes upon Enzyme adsorption. Moreover, lignin thin films were deposited on quartz crystal microgravimetry (QCM) and surface plasmon (SPR) resonance sensors and used to gain further insights into the lignin–cellulase interactions. For this purpose, a commercial multicomponent Enzyme system and a monocomponent Trichoderma reesei exoglucanase (CBH-I) were considered. Strong Enzyme adsorption was observed on the various lignins but compared to the multicomponent cellulases, CBH-I displayed lower surface affinity and higher Binding reversibility. This resolved prevalent questions related to the affinity of th...
-
Lignin Films from Spruce, Eucalyptus, and Wheat Straw Studied with Electroacoustic and Optical Sensors: Effect of Composition and Electrostatic Screening on Enzyme Binding
2017Co-Authors: Antonio Pereira, Ingrid C. Hoeger, Ana Ferrer, Jorge Rencoret, José C. Del Rio, Kristiina Kruus, Jenni Rahikainen, Miriam Kellock, Ana Gutiérrez, Orlando J. RojasAbstract:Lignins were isolated from spruce, wheat straw, and eucalyptus by using the milled wood lignin (MWL) method. Functional groups and compositional analyses were assessed via 2D NMR and 31P NMR to realize their effect on Enzyme Binding. Films of the lignins were fabricated and ellipsometry, atomic force microscopy, and water contact angle measurements were used for their characterization and to reveal the changes upon Enzyme adsorption. Moreover, lignin thin films were deposited on quartz crystal microgravimetry (QCM) and surface plasmon (SPR) resonance sensors and used to gain further insights into the lignin–cellulase interactions. For this purpose, a commercial multicomponent Enzyme system and a monocomponent Trichoderma reesei exoglucanase (CBH-I) were considered. Strong Enzyme adsorption was observed on the various lignins but compared to the multicomponent cellulases, CBH-I displayed lower surface affinity and higher Binding reversibility. This resolved prevalent questions related to the affinity of this Enzyme with lignin. Remarkably, a strong correlation between Enzyme Binding and the syringyl/guaiacyl (S/G) ratio was found for the lignins, which presented a similar hydroxyl group content (31P NMR): higher protein affinity was determined on isolated spruce lignin (99% G units), while the lowest adsorption occurred on isolated eucalyptus lignin (70% S units). The effect of electrostatic interactions in Enzyme adsorption was investigated by SPR, which clearly indicated that the screening of charges allowed more extensive protein adsorption. Overall, this work furthers our understanding of lignin–cellulase interactions relevant to biomass that has been subjected to no or little pretreatment and highlights the widely contrasting effects of the nature of lignin, which gives guidance to improve lignocellulosic saccharification and related processes
-
inhibitory effect of lignin during cellulose bioconversion the effect of lignin chemistry on non productive Enzyme adsorption
Bioresource Technology, 2013Co-Authors: Jenni Rahikainen, Orlando J. Rojas, Raquel Martinsampedro, Harri Heikkinen, Stella Rovio, Kaisa Marjamaa, Tarja Tamminen, Kristiina KruusAbstract:The effect of lignin as an inhibitory biopolymer for the enzymatic hydrolysis of lignocellulosic biomass was studied; specially addressing the role of lignin in non-productive Enzyme adsorption. Botanical origin and biomass pre-treatment give rise to differences in lignin structure and the effect of these differences on Enzyme Binding and inhibition were elucidated. Lignin was isolated from steam explosion (SE) pre-treated and non-treated spruce and wheat straw and used for the preparation of ultrathin films for Enzyme Binding studies. Binding of Trichoderma reesei Cel7A (CBHI) and the corresponding Cel7A-core, lacking the linker and the cellulose-Binding domain, to the lignin films was monitored using a quartz crystal microbalance (QCM). SE pre-treatment altered the lignin structure, leading to increased Enzyme adsorption. Thus, the positive effect of SE pre-treatment, opening the cell wall matrix to make polysaccharides more accessible, may be compromised by the structural changes of lignin that increase non-productive Enzyme adsorption.