Generalized rate equation for single-substrate enzyme catalyzed reactions

Kargi F.

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, vol.382, no.1, pp.157-159, 2009 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 382 Issue: 1
  • Publication Date: 2009
  • Doi Number: 10.1016/j.bbrc.2009.02.155
  • Journal Name: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.157-159
  • Keywords: Enzyme kinetics, Substrate limitation, Enzyme limitation, Generalized rate expression
  • Dokuz Eylül University Affiliated: No

Abstract

The most widely used rate expression for single-substrate enzyme catalyzed reactions, namely the Michaelis-Menten kinetics is based upon the assumption that enzyme concentration is in excess of the substrate in the medium and the rate is mainly limited by the substrate concentration according to saturation kinetics. However, this is only a special case and the actual rate expression varies depending on the initial enzyme/substrate ratio (E(o)/S(o)). When the substrate concentration exceeds the enzyme concentration the limitation is due to low enzyme concentration and the rate increases with the enzyme concentration according to saturation kinetics. The maximum rate is obtained when the initial concentrations of the enzyme and the Substrate are equal. A generalized rate equation was developed in this study and special cases were discussed for enzyme catalyzed reactions. (C) 2009 Elsevier Inc. All rights reserved.