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Francesc X Aviles - One of the best experts on this subject based on the ideXlab platform.
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the three dimensional structure of the native ternary complex of bovine pancreatic procarboxypeptidase a with proproteinase e and Chymotrypsinogen c
The EMBO Journal, 1995Co-Authors: F X Gomisruth, Wolfram Bode, Robert Huber, M Gomez, Francesc X AvilesAbstract:The metalloexozymogen procarboxypeptidase A is mainly secreted in ruminants as a ternary complex with zymogens of two serine endoproteinases, Chymotrypsinogen C and proproteinase E. The bovine complex has been crystallized, and its molecular structure analysed and refined at 2.6 A resolution to an R factor of 0.198. In this heterotrimer, the activation segment of procarboxypeptidase A essentially clamps the other two subunits, which shield the activation sites of the former from tryptic attack. In contrast, the propeptides of both serine proproteinases are freely accessible to trypsin. This arrangement explains the sequential and delayed activation of the constituent zymogens. Procarboxypeptidase A is virtually identical to the homologous monomeric porcine form. Chymotrypsinogen C displays structural features characteristic for chymotrypsins as well as elastases, except for its activation domain; similar to bovine Chymotrypsinogen A, its binding site is not properly formed, while its surface located activation segment is disordered. The proproteinase E structure is fully ordered and strikingly similar to active porcine elastase; its specificity pocket is occluded, while the activation segment is fixed to the molecular surface. This first structure of a native zymogen from the proteinase E/elastase family does not fundamentally differ from the serine proproteinases known so far.
Ashlesha Deshpande - One of the best experts on this subject based on the ideXlab platform.
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protein protein interactions in reverse micelles trypsin shows superactivity towards a protein substrate α Chymotrypsinogen a in reverse micelles of sodium bis 2 ethylhexyl sulfosuccinate aot in isooctane
Biochimie, 1993Co-Authors: Nitin W Fadnavis, Y Chandraprakash, Ashlesha DeshpandeAbstract:Abstract Protein-protein interactions in reverse micelles of sodium bis(2-ethylhexy)sulfosuccinate (AOT), in isooctane containing varying amounts of Tris buffer are studied by using activation of α-Chymotrypsinogen A by trypsin (EC 3.4.21.4) to α-chymotrypsin (EC 3.4.21.1) as a model reaction. It has been found that protein-protein interactions are strongly dependent on the water content of the medium. At an optimum water content the activation reaction in reverse micelles is faster than reaction in water by a factor of 21.3. At lower water content both reaction rates and the conversion of α-Chymotrypsinogen A into α-chytomotrysin decrease with decrease in water content of the reaction medium.
Satoshi Hamada - One of the best experts on this subject based on the ideXlab platform.
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removal of dodecyl sulfate ions bound to bovine serum albumin and Chymotrypsinogen from the proteins effects of reduction of disulfide bridges and cleavage of peptide bonds on the removal extent
Journal of Colloid and Interface Science, 1991Co-Authors: K. Takeda, Akira Wada, Yasuhiro Sato, Satoshi HamadaAbstract:Abstract The removal of dodecyl sulfate (DS) ions which had bound to proteins, bovine serum albumin (BSA) and Chymotrypsinogen, was attempted by precipitating the surfactant ions by the addition of a dipotassium hydrogen and potassium dihydrogen phosphate mixture. The effects of reduction of disulfide bridges and cleavage at peptide bonds on the removal of DS ion were examined. The amount of DS ion remaining on the proteins after the removal treatment sharply depended on the potassium ion concentration up to 150 mM in each case. At high concentrations of potassium ion, the amount of the remaining DS ion was approximately 25 and 10 mol/mol for the intact BSA and the disulfide bridges-reduced BSA, respectively. The amount was approximately 35 and 10 mol/mol for the intact Chymotrypsinogen and the disulfide bridges-reduced Chymotrypsinogen, respectively. No appreciable amount of DS ion remained on doubly-cleaved BSA and doubly-cleaved Chymotrypsinogen, that is, α-chymotrypsin (in both cases the resulting three polypeptide chains produced on cleavage are joined with disulfide bridges). On the other hand, each protein was recovered with no appreciable loss at any potassium ion concentration. The recovery of protein conformation was examined on the intact BSA by circular dichroism measurements. The secondary structure of the protein was recovered to the original one in spite of the remaining DS ion of about 25 mol/mol.
F X Gomisruth - One of the best experts on this subject based on the ideXlab platform.
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the three dimensional structure of the native ternary complex of bovine pancreatic procarboxypeptidase a with proproteinase e and Chymotrypsinogen c
The EMBO Journal, 1995Co-Authors: F X Gomisruth, Wolfram Bode, Robert Huber, M Gomez, Francesc X AvilesAbstract:The metalloexozymogen procarboxypeptidase A is mainly secreted in ruminants as a ternary complex with zymogens of two serine endoproteinases, Chymotrypsinogen C and proproteinase E. The bovine complex has been crystallized, and its molecular structure analysed and refined at 2.6 A resolution to an R factor of 0.198. In this heterotrimer, the activation segment of procarboxypeptidase A essentially clamps the other two subunits, which shield the activation sites of the former from tryptic attack. In contrast, the propeptides of both serine proproteinases are freely accessible to trypsin. This arrangement explains the sequential and delayed activation of the constituent zymogens. Procarboxypeptidase A is virtually identical to the homologous monomeric porcine form. Chymotrypsinogen C displays structural features characteristic for chymotrypsins as well as elastases, except for its activation domain; similar to bovine Chymotrypsinogen A, its binding site is not properly formed, while its surface located activation segment is disordered. The proproteinase E structure is fully ordered and strikingly similar to active porcine elastase; its specificity pocket is occluded, while the activation segment is fixed to the molecular surface. This first structure of a native zymogen from the proteinase E/elastase family does not fundamentally differ from the serine proproteinases known so far.
Nitin W Fadnavis - One of the best experts on this subject based on the ideXlab platform.
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protein protein interactions in reverse micelles trypsin shows superactivity towards a protein substrate α Chymotrypsinogen a in reverse micelles of sodium bis 2 ethylhexyl sulfosuccinate aot in isooctane
Biochimie, 1993Co-Authors: Nitin W Fadnavis, Y Chandraprakash, Ashlesha DeshpandeAbstract:Abstract Protein-protein interactions in reverse micelles of sodium bis(2-ethylhexy)sulfosuccinate (AOT), in isooctane containing varying amounts of Tris buffer are studied by using activation of α-Chymotrypsinogen A by trypsin (EC 3.4.21.4) to α-chymotrypsin (EC 3.4.21.1) as a model reaction. It has been found that protein-protein interactions are strongly dependent on the water content of the medium. At an optimum water content the activation reaction in reverse micelles is faster than reaction in water by a factor of 21.3. At lower water content both reaction rates and the conversion of α-Chymotrypsinogen A into α-chytomotrysin decrease with decrease in water content of the reaction medium.