Reference : Purification and properties of the exocellular β-lactamase of Actinomadura strain R39
Scientific journals : Article
Life sciences : Microbiology
http://hdl.handle.net/2268/66865
Purification and properties of the exocellular β-lactamase of Actinomadura strain R39
English
Duez, Colette mailto [Université de Liège - ULg > Institut de Chimie > Service de Microbiologie > >]
Frère, Jean-Marie mailto [Université de Liège - ULg > Institut de Chimie > Service de Microbiologie > >]
Ghuysen, Jean-Marie [Université de Liège - ULg > Institut de Chimie > Service de Microbiologie > > >]
Van Beeumen, Jozef [Rijksuniversiteit Gent Belgium - RUG > > Laboratorium voor Microbiologie > > >]
Delcambe, Lucien [Centre National pour la Production et l'Etude de Substances d'Origine Mircobienne - CNPEM > > > > >]
Dierickx, Louis [Centre National pour la Production et l'Etude de Substances d'Origine Mircobienne - CNPEM > > > > >]
1982
Biochimica et Biophysica Acta - General Subjects
Elsevier Science
700
24-32
Yes (verified by ORBi)
International
0304-4165
Amsterdam
[en] beta-lactamase ; R39 ; Carboxypeptidases/metabolism ; Zinc ; X-Ray Diffraction ; Streptomyces/enzymology ; Protein Conformation ; Muramoylpentapeptide Carboxypeptidase/metabolism ; Metalloproteins ; Catalysis
[en] The exocellular beta-lactamase (penicillin amido-beta-lactamhydrolase, EC 3.5.2.6) of Actinomadura R39 consists of one single polypeptide chain of molecular weight about 15 200. It exhibits a highly asymmetrical shape, has a low isoelectric point (at pH 5.0) and contains about 9.3% (w/w) of a polydeoxyribonucleotide with which it forms a rather stable complex. Removal of a substantial amount of this deoxyribonucleotide by treatment with DNAase I has no effect on the enzyme activity. The beta-lactamase has a wide spectrum of activity. Penicillins and delta 3-cephalosporins can be either good or poor substrates. Oxacillin, which is a poor substrate of most beta-lactamases from Gram-positive bacteria, is a good substrate of the beta-lactamase of Actinomadura R39. Its best substrate, however, is nitrocefin (kcat/Km: 2300 000 M-1.s-1; catalytic centre activity: 210 s-1). The kcat/Km values observed with some penicillins and delta 3-cephalosporins are similar to the values of the bimolecular rate constants that govern the formation of the acyl-enzyme intermediates between these antibiotics and the serine D-alanyl-D-alanine peptidase that is also secreted by the same strain Actinomadura R39. Such a relationship, however, is not observed with all the beta-lactam compounds tested.
National Institutes of Health - NIH ; Fonds de la Recherche Scientifique Médicale - FRSM
Researchers ; Professionals
http://hdl.handle.net/2268/66865

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