The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
David Messdaghi - One of the best experts on this subject based on the ideXlab platform.
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Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues.
Biochimica et biophysica acta, 2000Co-Authors: David Messdaghi, K DietzAbstract:Intercellular washing fluids from leaves of all tested higher plant species contained a serine-type protease which efficiently cleaved the artificial fluorogenic substrate MCA-Pro-Leu-Gly-Leu-Dnp-Ala-Arg (MCA). The activity varied between the species. The classification as serine protease was based on the sensitivity towards Chymostatin and phenylmethylsulfonyl fluoride. MCA protease activity strongly declined with leaf age and was also detected in stems, roots and flower petals. In tobacco, specific activity of the Chymostatin-sensitive MCA protease was about 40-fold higher in intercellular washing fluids than in whole leaf homogenate confirming the extracellular location of the MCA protease. The same enzyme activity was detected in developing tomato fruits; it showed a correlation with fruit growth and was not detectable in ripe fruits. The tobacco protease was sensitive to temperatures above 50 degrees C, had an isoelectric point of 5.8+/-0.1 and an apparent molecular mass of 68 kDa. Its pH optimum was very broad with little difference in activity between pH 5 and 9. Conversely, a casein-cleaving protease also present in intercellular washing fluids was insensitive towards Chymostatin and revealed a pronounced pH optimum around 6.0. The data biochemically characterize a new type of extracellular proteolytic activity which may be particularly important during tissue expansion.
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Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues
Biochimica et Biophysica Acta, 2000Co-Authors: David Messdaghi, Karl-josef DietzAbstract:Abstract Intercellular washing fluids from leaves of all tested higher plant species contained a serine-type protease which efficiently cleaved the artificial fluorogenic substrate MCA-Pro-Leu-Gly-Leu-Dnp-Ala-Arg (MCA). The activity varied between the species. The classification as serine protease was based on the sensitivity towards Chymostatin and phenylmethylsulfonyl fluoride. MCA protease activity strongly declined with leaf age and was also detected in stems, roots and flower petals. In tobacco, specific activity of the Chymostatin-sensitive MCA protease was about 40-fold higher in intercellular washing fluids than in whole leaf homogenate confirming the extracellular location of the MCA protease. The same enzyme activity was detected in developing tomato fruits; it showed a correlation with fruit growth and was not detectable in ripe fruits. The tobacco protease was sensitive to temperatures above 50°C, had an isoelectric point of 5.8±0.1 and an apparent molecular mass of 68 kDa. Its pH optimum was very broad with little difference in activity between pH 5 and 9. Conversely, a casein-cleaving protease also present in intercellular washing fluids was insensitive towards Chymostatin and revealed a pronounced pH optimum around 6.0. The data biochemically characterize a new type of extracellular proteolytic activity which may be particularly important during tissue expansion.
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Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues
Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 2000Co-Authors: David Messdaghi, Karl-josef DietzAbstract:Messdaghi D, Dietz K-J. Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEIN STRUCTURE AND MOLECULAR ENZYMOLOGY. 2000;1480(1-2):107-116.Intercellular washing fluids from leaves of all tested higher plant species contained a serine-type protease which efficiently cleaved the artificial fluorogenic substrate MCA-Pro-Leu-Gly-Leu-Dnp-Ala-Arg (MCA). The activity varied between the species. The classification as serine protease was based on the sensitivity towards Chymostatin and phenylmethylsulfonyl fluoride. MCA protease activity strongly declined with leaf age and was also detected in stems, roots and flower petals. In tobacco, specific activity of the Chymostatin-sensitive MCA protease was about 40-fold higher in intercellular washing fluids than in whole leaf homogenate confirming the extracellular location of the MCA protease. The same enzyme activity was detected in developing tomato fruits; it showed a correlation with fruit growth and was not detectable in ripe fruits. The tobacco protease was sensitive to temperatures above 50 degrees C, had an isoelectric point of 5.8 +/- 0.1 and an apparent molecular mass of 68 kDa. Its pH optimum was very broad with little difference in activity between pH 5 and 9. Conversely, a casein-cleaving protease also present in intercellular washing fluids was insensitive towards Chymostatin and revealed a pronounced pH optimum around 6.0. The data biochemically characterize a new type of extracellular proteolytic activity which may be particularly important during tissue expansion. (C) 2000 Elsevier Science B.V. All rights reserved
Karl-josef Dietz - One of the best experts on this subject based on the ideXlab platform.
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Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues
Biochimica et Biophysica Acta, 2000Co-Authors: David Messdaghi, Karl-josef DietzAbstract:Abstract Intercellular washing fluids from leaves of all tested higher plant species contained a serine-type protease which efficiently cleaved the artificial fluorogenic substrate MCA-Pro-Leu-Gly-Leu-Dnp-Ala-Arg (MCA). The activity varied between the species. The classification as serine protease was based on the sensitivity towards Chymostatin and phenylmethylsulfonyl fluoride. MCA protease activity strongly declined with leaf age and was also detected in stems, roots and flower petals. In tobacco, specific activity of the Chymostatin-sensitive MCA protease was about 40-fold higher in intercellular washing fluids than in whole leaf homogenate confirming the extracellular location of the MCA protease. The same enzyme activity was detected in developing tomato fruits; it showed a correlation with fruit growth and was not detectable in ripe fruits. The tobacco protease was sensitive to temperatures above 50°C, had an isoelectric point of 5.8±0.1 and an apparent molecular mass of 68 kDa. Its pH optimum was very broad with little difference in activity between pH 5 and 9. Conversely, a casein-cleaving protease also present in intercellular washing fluids was insensitive towards Chymostatin and revealed a pronounced pH optimum around 6.0. The data biochemically characterize a new type of extracellular proteolytic activity which may be particularly important during tissue expansion.
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Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues
Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 2000Co-Authors: David Messdaghi, Karl-josef DietzAbstract:Messdaghi D, Dietz K-J. Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEIN STRUCTURE AND MOLECULAR ENZYMOLOGY. 2000;1480(1-2):107-116.Intercellular washing fluids from leaves of all tested higher plant species contained a serine-type protease which efficiently cleaved the artificial fluorogenic substrate MCA-Pro-Leu-Gly-Leu-Dnp-Ala-Arg (MCA). The activity varied between the species. The classification as serine protease was based on the sensitivity towards Chymostatin and phenylmethylsulfonyl fluoride. MCA protease activity strongly declined with leaf age and was also detected in stems, roots and flower petals. In tobacco, specific activity of the Chymostatin-sensitive MCA protease was about 40-fold higher in intercellular washing fluids than in whole leaf homogenate confirming the extracellular location of the MCA protease. The same enzyme activity was detected in developing tomato fruits; it showed a correlation with fruit growth and was not detectable in ripe fruits. The tobacco protease was sensitive to temperatures above 50 degrees C, had an isoelectric point of 5.8 +/- 0.1 and an apparent molecular mass of 68 kDa. Its pH optimum was very broad with little difference in activity between pH 5 and 9. Conversely, a casein-cleaving protease also present in intercellular washing fluids was insensitive towards Chymostatin and revealed a pronounced pH optimum around 6.0. The data biochemically characterize a new type of extracellular proteolytic activity which may be particularly important during tissue expansion. (C) 2000 Elsevier Science B.V. All rights reserved
Robert J. Beynon - One of the best experts on this subject based on the ideXlab platform.
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Synthetic analogues of the proteinase inhibitor: Chymostatin.
International journal of peptide and protein research, 2009Co-Authors: I.j. Galpin, Graham A. Place, A H Wilby, Robert J. BeynonAbstract:Putative proteinase inhibitors with the general structure Z. Arg. X.Phe.H (where X = Leu, Ile or Val) were prepared by solution synthesis using semicarbazone protection for the aldehyde function. These inhibitors showed strong activity towards chymotrypsin whereas the semicarbazones and dipeptides aldehydes showed considerably reduced activity. The structural requirements for inhibition would seem to mimic those of the natural chymotrypsin inhibitor Chymostatin.
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Synthetic analogues of Chymostatin. Inhibition of chymotrypsin and Streptomyces griseus proteinase A.
Biochemical Journal, 1992Co-Authors: N P Tomkinson, I.j. Galpin, Robert J. BeynonAbstract:A series of analogues of Chymostatin, including Z-Arg-Leu-Phe-aldehyde (Z-Arg-Leu-Phe-H), have been synthesized. Analysis of the inhibitory potential of these analogues permits identification of residues and interactions that are important for inhibitory activity. Moreover, the structure-function relationship for Z-Arg-Leu-Phe-H and Chymostatin inhibition of chymotrypsin and Streptomyces griseus proteinase A (SGPA) was probed further with the aid of molecular mechanics. This analysis identified interactions that provide an explanation for the enhanced activity of the natural product, Chymostatin, over the synthetic analogues in the inhibition of chymotrypsin but not SGPA.
Weidong Wang - One of the best experts on this subject based on the ideXlab platform.
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Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells
Lipids in health and disease, 2018Co-Authors: Miaojuan Qiu, Lizi Jin, Pinning Feng, Yonglun Kong, Xiaoduo Zhao, Yu Lin, Weidong WangAbstract:Lipotoxicity plays an important role in the pathogenesis of kidney injury. Our previous study demonstrated that activation of local renin-angiotensin system (RAS) was involved in saturated free fatty acids palmitic acid (PA)-induced tubular cell injuries. The current study aims to investigate whether suppression of RAS by combination of direct renin inhibitor aliskiren and noncanonical RAS pathway chymase inhibitor Chymostatin attenuates PA or cholesterol induced-endoplasmic reticulum stress (ER stress) and apopotosis in cultured human proximal tubular HK2 cells. HK2 cells were treated with saturated fatty acid PA (0.6 mM) for 24 h or cholesterol (10 μg/ml) for 6d with or without Chymostatin and/or aliskiren. Expressions of the ER stress associated proteins and apoptosis markers were detected by western blotting. The mRNA levels of RAS components were measured by real-time qPCR. Combination treatment of Chymostatin and aliskiren markedly suppressed PA or cholesterol-induced ER stress, as reflected by increased BiP, IRE1α, phosphorylated-eIF2α and ATF4 as well as proapoptotic transcription factor CHOP. The ratio of Bax/Bcl-2 and cleaved caspase-3, two markers of apoptosis were upregulated by PA or cholesterol treatment. PA treatment was also associated with increased levels of angiotensinogen and angiotensin type 1 receptor (AT1R) mRNA expression. Combination treatment of Chymostatin and aliskiren markedly suppressed PA or cholesterol-induced ER stress and apoptosis. The protective effect of two inhibitors was also observed in primary cultured cortical tubular cells treated with PA. In contrast, Chymostatin and/or aliskiren failed to prevent ER stress induced by tunicamycin. These results suggested that combination treatment of Chymostatin and aliskiren attenuates lipid-induced renal tubular cell injury, likely through suppressing activation of intracellular RAS.
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Additional file 1: of Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells
2018Co-Authors: Miaojuan Qiu, Lizi Jin, Pinning Feng, Yonglun Kong, Xiaoduo Zhao, Yu Lin, Weidong WangAbstract:Figure A1. mRNA levels of RAS components in HK2 cells treated with palmitic acid. A. The mRNA levels of chymase, angiotensinogen, ACE in PA-treated HK2 cells with Chymostatin and/or aliskiren. B. The mRNA levels of AT1R in PA-treated HK2 cells with Chymostatin and/or aliskiren. Representative results of three independent experiments are shown. ATG: angiotensinogen; ACE: angiotensin converting enzyme; AT1R: angiotensin type 1 receptor; CTL, controls; PA, palmitic acid treatment group; PA + CMT, palmitic acid plus Chymostatin treatment; PA + Ali, palmitic acid plus aliskiren treatment; PA + CMT + Ali, palmitic acid plus Chymostatin and aliskiren treatment. * p
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Additional file 3: of Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells
2018Co-Authors: Miaojuan Qiu, Lizi Jin, Pinning Feng, Yonglun Kong, Xiaoduo Zhao, Yu Lin, Weidong WangAbstract:Figure A3. Combination treatment with Chymostatin and aliskiren markedly prevented ER stress and apoptosis in primary cultured tubular cells treated with palmitic acid (0.2 mM) for 12 h. A. Protein abundance of ER stress markers (BiP, p-eIF2α/eIF2α, CHOP) were upregulated induced by PA, whereas pretreatment with Chymostatin (5X10−5M) and aliskiren (10− 8 M) attenuated ER stress induced by PA. The increased level of cleaved caspase-3 induced by PA was also prevented by the combination treatment with Chymostatin and aliskiren. B. Quantitative analysis of ER stress marker levels normalized to β-actin. C. Ratio of p-eIF2α and eIF2α. D. Quantitative analysis of cleaved-caspased 3 levels normalized to β-actin. Representative results of three independent experiments are shown. CTL, controls; PA, palmitic acid treatment group; PA + CMT, palmitic acid plus Chymostatin treatment; PA + Ali, palmitic acid plus aliskiren treatment; PA + CMT + Ali, palmitic acid plus Chymostatin and aliskiren treatment. * p
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Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells
BMC, 2018Co-Authors: Miaojuan Qiu, Lizi Jin, Pinning Feng, Yonglun Kong, Xiaoduo Zhao, Yu Lin, Weidong WangAbstract:Abstract Background Lipotoxicity plays an important role in the pathogenesis of kidney injury. Our previous study demonstrated that activation of local renin-angiotensin system (RAS) was involved in saturated free fatty acids palmitic acid (PA)-induced tubular cell injuries. The current study aims to investigate whether suppression of RAS by combination of direct renin inhibitor aliskiren and noncanonical RAS pathway chymase inhibitor Chymostatin attenuates PA or cholesterol induced-endoplasmic reticulum stress (ER stress) and apopotosis in cultured human proximal tubular HK2 cells. Methods HK2 cells were treated with saturated fatty acid PA (0.6 mM) for 24 h or cholesterol (10 μg/ml) for 6d with or without Chymostatin and/or aliskiren. Expressions of the ER stress associated proteins and apoptosis markers were detected by western blotting. The mRNA levels of RAS components were measured by real-time qPCR. Results Combination treatment of Chymostatin and aliskiren markedly suppressed PA or cholesterol-induced ER stress, as reflected by increased BiP, IRE1α, phosphorylated-eIF2α and ATF4 as well as proapoptotic transcription factor CHOP. The ratio of Bax/Bcl-2 and cleaved caspase-3, two markers of apoptosis were upregulated by PA or cholesterol treatment. PA treatment was also associated with increased levels of angiotensinogen and angiotensin type 1 receptor (AT1R) mRNA expression. Combination treatment of Chymostatin and aliskiren markedly suppressed PA or cholesterol-induced ER stress and apoptosis. The protective effect of two inhibitors was also observed in primary cultured cortical tubular cells treated with PA. In contrast, Chymostatin and/or aliskiren failed to prevent ER stress induced by tunicamycin. Conclusions These results suggested that combination treatment of Chymostatin and aliskiren attenuates lipid-induced renal tubular cell injury, likely through suppressing activation of intracellular RAS
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Additional file 2: of Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells
2018Co-Authors: Miaojuan Qiu, Lizi Jin, Pinning Feng, Yonglun Kong, Xiaoduo Zhao, Yu Lin, Weidong WangAbstract:Figure A2. Combination treatment with Chymostatin and aliskiren couldn’t prevent ER stress in HK2 cells treated with tunicamycin (2 μg/ml). A. Tunicamycin induced upregulation of the ER markers (BiP and CHOP) expression in HK2 cells, neither pretreatment with Chymostatin (5X10−5M) nor aliskiren (10− 8 M) attenuated ER stress induced by TM. B. Quantitative analysis of ER stress marker levels normalized to β-actin. Representative results of three independent experiments are shown. * p
K Dietz - One of the best experts on this subject based on the ideXlab platform.
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Characterization of an extracellular Chymostatin-sensitive serine protease preferentially expressed in young plant tissues.
Biochimica et biophysica acta, 2000Co-Authors: David Messdaghi, K DietzAbstract:Intercellular washing fluids from leaves of all tested higher plant species contained a serine-type protease which efficiently cleaved the artificial fluorogenic substrate MCA-Pro-Leu-Gly-Leu-Dnp-Ala-Arg (MCA). The activity varied between the species. The classification as serine protease was based on the sensitivity towards Chymostatin and phenylmethylsulfonyl fluoride. MCA protease activity strongly declined with leaf age and was also detected in stems, roots and flower petals. In tobacco, specific activity of the Chymostatin-sensitive MCA protease was about 40-fold higher in intercellular washing fluids than in whole leaf homogenate confirming the extracellular location of the MCA protease. The same enzyme activity was detected in developing tomato fruits; it showed a correlation with fruit growth and was not detectable in ripe fruits. The tobacco protease was sensitive to temperatures above 50 degrees C, had an isoelectric point of 5.8+/-0.1 and an apparent molecular mass of 68 kDa. Its pH optimum was very broad with little difference in activity between pH 5 and 9. Conversely, a casein-cleaving protease also present in intercellular washing fluids was insensitive towards Chymostatin and revealed a pronounced pH optimum around 6.0. The data biochemically characterize a new type of extracellular proteolytic activity which may be particularly important during tissue expansion.