Enzyme kinetics: the whole picture reveals hidden meanings

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Maria F. Pinto (Author) Other; Rosa Crespo (Author) Other; Fernando A. Rocha (Author) FEUP; Ana M. Damas (Author) Other; Pedro M. Martins (Author) FEUP; Berta N. Estevinho (Author) FEUP

Journal

Title: FEBS Journal

Vol. 282 No. 12

Pages: 2309-2316

ISSN: 1742-464X

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 4 Citations

ISI Web of Science

Scopus - 0 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

CORDIS: Technological sciences

Associated Projects

LEPABE - Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia

Other information

Authenticus ID: P-016-TFE

DOI: 10.1111/febs.13275

Abstract (EN): The methodology adopted by Michaelis and Menten in 1913 is still routinely used to characterize the catalytic power and selectivity of enzymes. These kinetic measurements must be performed soon after the purified enzyme is mixed with a large excess of substrate. Other time scales and solution compositions are no less physiologically relevant, but fall outside the range of applicability of the classical formalism. Here we show that the complete picture of an enzyme's mode of function is critically obscured by the limited scope of conventional kinetic analysis, even in the simplest case of a single active site without inhibition. This picture is now unveiled in a mathematically closed form that remains valid over the reaction time for all combinations of enzyme/substrate concentrations and rate constants. Algebraic simplicity is maintained in the new formalism when stationary reaction phases are considered. By achieving this century-old objective, the otherwise hidden role of the reversible binding step is revealed and atypical kinetic profiles are explained. Most singular kinetic behaviors are identified in a critical region of conditions that coincide with typical cell conditions. Because it is not covered by the Michaelis-Menten model, the critical region has been missed until now by low-and high-throughput screenings of new drugs. New possibilities are therefore raised for novel and once-promising inhibitors to therapeutically target enzymes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8