Reference : Effects of nucleophiles on the breakdown of the benzylpenicilloyl-enzyme complex EI f...
Scientific journals : Article
Life sciences : Microbiology
Life sciences : Biochemistry, biophysics & molecular biology
http://hdl.handle.net/2268/91723
Effects of nucleophiles on the breakdown of the benzylpenicilloyl-enzyme complex EI formed between benzylpenicillin and the exocellular DD-carboxypeptidase--transpeptiase of Streptomyces strain R61
English
Marquet, Alberto [Université de Liège - ULiège > Institut de Botanique > Service de Microbiologie > > >]
Frère, Jean-Marie mailto [Université de Liège - ULiège > Institut de Botanique > Service de Microbiologie > >]
Ghuysen, Jean-Marie [Université de Liège - ULiège > Institut de Botanique > Service de Microbiologie > >]
Loffet, Albert [UCB > > > > >]
1-Mar-1979
Biochemical Journal
Portland Press
177
3
909-916
Yes (verified by ORBi)
International
0264-6021
1470-8728
London
United Kingdom
[en] alcohols/pharmacology ; amines/pharmacology ; carboxypeptidases/*metabolism ; chemical Phenomena ; chemistry ; glycerol/pharmacology ; hydroxylamines/pharmacology ; muramoylpentapeptide carboxypeptidase/*metabolism ; penicillin g/*metabolism ; peptides/pharmacology ; serine/metabolism ; streptomyces/*enzymology
[en] Serine is one of the enzyme residues with which benzylpenicillin collides as a result of its binding to the Streptomyces strain-R61 DD-carboxypeptidase-transpeptidase enzyme. Nucleophilic attack occurs on C(7) of the bound antibiotic molecule with formation of a benzylpenicilloyl-serine ester linkage, i.e. formation of the benzylpenicilloyl-enzyme EI complex. To reject the bound penicilloyl moiety and consequently to recover its initial activities, the strain-R61 enzyme has developed two possible mechanisms. Pathway A is a direct attack of the serine ester linkage by an exogenous nucleophile, resulting in the transfer of the benzylpenicilloyl moiety to this nucleophile. In pathway B, the benzylpenicilloyl moiety is first fragmented by C(5)-C(6) cleavage and the enzyme-bound phenylacetylglycyl residue thus produced is in turn transferred to the nucleophile. Pathway B occurs with water, glycylglycine and other amino compounds. Both pathways A and B occur with glycerol, other ROH nucleophiles and neutral hydroxylamine. The nucleophilic attacks are enzyme-catalysed.
National Institutes of Health - NIH
Researchers ; Professionals
http://hdl.handle.net/2268/91723

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