Substrate and Product Inhibition Initial Rate Kinetics of Histone Acetyltransferase

John E. Wiktorowicz, Kenneth L. Campos, James Bonner

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Initial velocity and product inhibition kinetics of the histone acetyltransferase (EC 2.3.1.48) reaction indicate that the rat liver nuclear enzyme operates under a rapid equilibrium ordered bireactant mechanism. Histone adds first to the enzyme, and under the conditions of the experiment Ka = 0 as acetyl coenzyme A. (CoA) concentration approaches saturating conditions. The Km for acetyl-CoA was 2.10 ± 0.48 µM. Inhibition with acetyllysine resulted in a Ka for the enzyme-acetyllysine complex of 1.96 ± 0.30 mM. Inhibition with CoA yielded Kiq for the ternary complex of 3.19 ± 0.48 µM. These results indicate that the enzyme activity is comparatively independent of histone concentration, and, since the enzyme is sensitive only to acetyl-CoA and CoA concentrations, the enzyme will tend to maintain histones in the acetylated state.

Original languageEnglish (US)
Pages (from-to)1464-1467
Number of pages4
JournalBiochemistry
Volume20
Issue number6
DOIs
StatePublished - Mar 1981
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Substrate and Product Inhibition Initial Rate Kinetics of Histone Acetyltransferase'. Together they form a unique fingerprint.

  • Cite this