The theoretical analysis of kinetic behaviour of 'hysteretic' allosteric enzymes. I. The kinetic manifestations of slow conformational change of an oligomeric enyzme in the Monod, Wyman and Changeux model

Autor: V.A. Yakovlev, Dorozhko Ai, Kagan Zs, Kurganov Bi
Rok vydání: 1976
Předmět:
Zdroj: Journal of Theoretical Biology. 60:247-269
ISSN: 0022-5193
DOI: 10.1016/0022-5193(76)90059-x
Popis: The curves of the time ( t ) dependent product (Pr) accumulation for Monod, Wyman & Changeux model (1965) , where the rate of installation of equilibrium between two conformational states of oligomeric enzyme (R ⇄ T) is comparable to that of enzymatic process, are theoretically analysed. It is assumed that the complexes of R and T forms are in rapid equilibrium with the free components. The character of the effective rate constant of conformational transition R ⇄ T and the value of τ (where τ is the intercept of the linear part of the kinetic curve of [Pr] versus t with the time axis) versus the substrate concentration is analysed. It is also shown that slow conformational transition R ⇄ T can be manifested by an unusual shape for Monod et al. model plots of initial velocity of the enzyme reaction v . the substrate concentration (these curves can clearly display expressed inflection points and Hill's cooperativity coefficient less than unity).
Databáze: OpenAIRE