Article (Scientific journals)
Active-Site Serine Mutants of the Streptomyces Albus G Beta-Lactamase
Jacob, Françoise; Joris, Bernard; Frère, Jean-Marie
1991In Biochemical Journal, 277 ((Pt 3)), p. 647-52
Peer Reviewed verified by ORBi
 

Files


Full Text
Publi_37_med.txt
Publisher postprint (2.2 kB)
Download

All documents in ORBi are protected by a user license.

Send to



Details



Abstract :
[en] By using site-directed mutagenesis, the active-site serine residue of the Streptomyces albus G beta-lactamase was substituted by alanine and cysteine. Both mutant enzymes were produced in Streptomyces lividans and purified to homogeneity. The cysteine beta-lactamase exhibited a substrate-specificity profile distinct from that of the wild-type enzyme, and its kcat./Km values at pH 7 were never higher than 0.1% of that of the serine enzyme. Unlike the wild-type enzyme, the activity of the mutant increased at acidic pH values. Surprisingly, the alanine mutant exhibited a weak but specific activity for benzylpenicillin and ampicillin. In addition, a very small production of wild-type enzyme, probably due to mistranslation, was detected, but that activity could be selectively eliminated. Both mutant enzymes were nearly as thermostable as the wild-type.
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Jacob, Françoise
Joris, Bernard ;  Université de Liège - ULiège > Centre d'ingénierie des protéines
Frère, Jean-Marie ;  Université de Liège - ULiège > Département des sciences de la vie > Département des sciences de la vie
Language :
English
Title :
Active-Site Serine Mutants of the Streptomyces Albus G Beta-Lactamase
Publication date :
01 August 1991
Journal title :
Biochemical Journal
ISSN :
0264-6021
eISSN :
1470-8728
Publisher :
Portland Press, United Kingdom
Volume :
277
Issue :
(Pt 3)
Pages :
647-52
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 21 May 2012

Statistics


Number of views
22 (0 by ULiège)
Number of downloads
13 (0 by ULiège)

Scopus citations®
 
17
Scopus citations®
without self-citations
13
OpenCitations
 
15

Bibliography


Similar publications



Contact ORBi