ChemNet
 
Previous article Next article Contents  

A. S. Jasnaya, O. V. Jamskova, D. T. Guranda, T. A. Shcherbakova, V. I. Tishkov, V. K. Shvedas

Cloning of penicillin acylase from Escherichia coli. Catalytic properties of recombinant enzymes

Abstract

Gene of penicillin acylase (PA) from Escherichia coli has been cloned from a producing strain analogous to strain ATCC 11105. Optimization of cultivation conditions allowed to obtain up to 130 mg of active enzyme from per litre of culture broth. A number of single, double and triple mutants has been produced by site specific mutagenesis. Homogeneous preparations of wild type enzyme and its mutants have been received due to isolation and purification. It was shown that 1) isolated enzymes have correctly folded structure; 2) complexing agents and metal ions do not inhibit catalytic activity; 3) penicillin acylase mutants are inactivated by phenylmethylsulphonyl fluoride as effective as a wild type enzyme what allows to use this reagent to titrate active sites of the mutants; 4) some of the tested enzyme mutants are characterized by higher specificity constants in hydrolysis of colorimetric substrate, however they are not as effective as a wild type penicillin acylase in biocatalytic ampicillin synthesis by acyl transfer.
Moscow University Chemistry Bulletin.
2008, Vol. 49, No. 2, P. 127
   

Copyright (C) Chemistry Dept., Moscow State University, 2002
   Overview
   Editorial board
   Tables of Contents
   Subscription

The site is supported by Russian Foundation for Basic Research
  The using of published on this page materials is not allowed without special permission
Copyright (C) Chemisty Department of Moscow State University
Web-Editor: B.I.Pokrovskii
Web-design: Copyright (C) MIG and VVM
webmaster@www.chem.msu.su