Kinetic studies with the use of proton-magnetic-resonance spectroscopy of the specific α-deuteration of amino acids by Escherichia coli aspartate aminotransferase

Autor: Gout, E, Chesne, S, Beguin, C G, Pelmont, J
Zdroj: Biochemical Journal; June 1978, Vol. 171 Issue: 3 p719-723, 5p
Abstrakt: Escherichia coli aspartate aminotransferase was exposed to aspartate or phenylalanine without oxo acid in buffered 2H2O. The alpha-hydrogen of the amino acids underwent first-order exchange with respect to both substrate and enzyme. P.m.r. spectroscopy gave consistent reaction-rate constants. The deuterium-exchange rate was only moderately increased by addition of oxo acids and was of the same order as the transamination rate. No beta-deuteration was observed. The C(alpha)-H-bond-breaking step is discussed as a part of the entire transamination mechanism.
Databáze: Supplemental Index