Kinetic and thermodynamic control of the relative yield of the deamidation of asparagine and isomerization of aspartic acid residues.
Selective deamidation of Asn67 of RNase A to beta-Asp67 and Asp67 residues at neutral pH initially produces greater amounts of the beta-Asp derivative. As the reaction proceeds the relative concentration of [Asp67]-RNase A increases and, at equilibrium, becomes predominant. Such a discrepancy between the kinetic and thermodynamic control on reaction products is discussed in light of information from X-ray three-dimensional analysis and the lower thermodynamic stability of the beta-Asp derivative relative to the parent enzyme.
Capasso
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Dipartimento di Scienze Ambientali, Seconda Università di Napoli, Caserta, Italy. sante.capasso@unina2.it
Di Cerbo
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P
D000818:Animals; D001216:Asparagine / Q000737:chemistry*; D001224:Aspartic Acid / Q000737:chemistry*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D007700:Kinetics; D008956:Models, Chemical; D010179:Pancreas / Q000201:enzymology; D012259:Ribonuclease, Pancreatic / Q000737:chemistry / Q000378:metabolism; D013388:Succinimides / Q000378:metabolism; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors
D013388:Succinimides; C032620:succinimide; D001224:Aspartic Acid; D001216:Asparagine; D012259:Ribonuclease, Pancreatic