[Peptide synthesis catalyzed by proteases. Analysis of a kinetic model for enzymes with acyl-enzyme mechanism of action].
The kinetics of peptide synthesis via transfer of the acyl moiety from activated derivatives of amino acids or peptides (S) to nucleophiles (N) catalyzed by proteases forming an acyl-enzyme intermediate, was analysed. A kinetic model assumes enzymatic hydrolysis of the formed peptide (P), so the kinetic curve for P has a maximum (denoted as pmax). Particular attention was given to the analysis of the effects of the initial concentrations and kinetic constants on pmax. Computer analysis demonstrated that at a given ratio of initial S and N concentrations pmax is affected only by the ratio of the second order rate constants for enzymatic hydrolysis of S and P (alpha) and the ratio of rate constants for an attack of the acyl-enzyme intermediate by nucleophile and water (beta). These conclusions apply regardless of the existence of enzyme forms other than a free enzyme and an acyl-enzyme intermediate. Thus, the kinetically controlled maximum yield of peptide (pmax) can be calculated a priori from the values of alpha and beta which can be readily evaluated from the reference data. Simple explicit expressions were obtained, allowing fairly accurate prediction of pmax for a broad spectrum of S and N initial concentrations.
Gololobov
M Iu
MIu
Borisov
I L
IL
Shviadas
V K
VK
D000215:Acylation; D006868:Hydrolysis; D007700:Kinetics; D008954:Models, Biological; D010452:Peptide Biosynthesis; D010447:Peptide Hydrolases / Q000378:metabolism*; D013379:Substrate Specificity; D013816:Thermodynamics
D010447:Peptide Hydrolases
Peptidnyĭ sintez, kataliziruemyĭ proteazami. Analiz kineticheskoĭ modeli dlia fermentov, deĭstvuiushchikh po atsilfermentnomu mekhanizmu.