Journal archive > 2012 > N 2 March-April

*K*/

_{m}^{app}= K_{s}+ k_{cat}*k*

_{1 }TRUE FOR ENZYME-CATALYSED

*S. O. Karakhim*

The article is dedicated to analysis of equation which expresses apparent Michaelis constant *K*_{m}^{app} of enzyme-catalysed reactions with activator participation by means of the substrate constant *K*_{s} and rate constant of enzyme-substrate complex decomposition *k _{cat}*. It has been shown that although it is possible to record the mechanisms of such reactions as a scheme similar to Michaelis-Menten model and to derive equation of apparent Michaelis constant as

*K*=

_{m}^{app}*K*+

_{s}*k*/

_{cat}*k*

_{1}, but this approach cannot be used for investigation of all reactions with activator participation. The equation mentioned above is not obeyed in the general case, it may be true for some mechanisms only or under certain ratio of kinetic parameters of enzyme-catalysed reactions.

**Key words:** enzyme kinetics, Michaelis-Menten equation, Michaelis constant, limiting rate, substrate constant, activator.

The original article in Russian is available for download in PDF format.

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