|
A. M. Luhavaya, V. G. Grigorenko
Study
of catalytic properties of recombinant class A TEM-1 b-lactamase and its iNhibition by sulbactam, tazobactam and
clavulanic acid
Abstract
In this work was studied homogeneous preparation of recombinant class A
TEM-1 b-lactamase; kinetic
parameters obtained with chromogenic substrate CENTA are as follows: KM
= 22 mM, V = 0,39 mM/s, kcat =
31,2 s-1, kcat/KM =1,4 mM-1s-1.
Based on the comparison of determined Michaelis constant (KM
= 22 mM) with literature data
it is approved that recombinant enzyme is about 3 times more specific against
CENTA than the native one (KM = 70 mM). It was ascertained
competitive type of inhibition for sulbactam, tazobactam and clavulanic acid.
For the first time the inhibition constants for recombinant b-lactamase TEM-1 with
CENTA as a substrate for sulbactam, tazobactam, clavulanic acid (KI(sulbactam)
= 0,43 mM,
KI(tazobactam) = 0,041 mM, KI(clavulanic
acid) = 0,046 mM) have been determined.
It was shown that tazobactam and clavulanic acid are the most effective inhibitors for the recombinant b-lactamase as having the
least value of KI and their inactivation influence can be
accepted as identical.
Copyright (C) Chemistry Dept., Moscow State University, 2002
|
|
