Open AccessKinetic studies on enzymatic acetylation of chloramphenicol in Streptococcus faecalis
Author(s) -
Yasuaki Nakagawa,
Yoshiyuki Nitahara,
Sadao Miyamura
Publication year - 1979
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.16.6.719
Subject(s) - acetylation , chloramphenicol , enzyme , chloramphenicol acetyltransferase , chemistry , derivative (finance) , streptococcus , diacetyl , kinetics , acetyltransferases , reaction rate constant , acetyltransferase , stereochemistry , nuclear chemistry , biochemistry , antibiotics , bacteria , biology , physics , gene expression , promoter , genetics , quantum mechanics , financial economics , economics , gene
The kinetics of chloramphenicol (CP) acetylation by CP acetyltransferase from Streptococcus faecalis was studied. CP was shown to be acetylated enzymatically to its 3-O-acetyl derivative (3-AcCP) in the presence of acetyl coenzyme A, after which 3-AcCP was converted nonenzymatically to its 1-O-acetyl isomer, 1-O-acetyl CP (1-AcCP). At equilibrium, the 1-AcCP and 3-AcCP were present in a 1:4 ratio. Subsequently the diacetylated product, 1,3-O-O-diacetyl CP [1,3-(Ac)2CP], was enzymatically produced from 1-AcCP by the same enzyme. Theoretical calculation of rate constants (k1, k2, k3) for each successive reaction is as follows: (Formula: see text). This calculation gave k1 = 0.4 min-1, k2 = 0.002 min-1, and k3 = 0.016 min-1. Experimental results agreed closely with these calculated values.