Evidence for an oxyanion hole in serine beta-lactamases and DD-peptidases.
نویسندگان
چکیده
A thionocephalosporin is shown to be a much poorer substrate of representative serine beta-lactamases of class A (RTEM-2) and class C (Enterobacter cloacae P99) and a much poorer inhibitor of the Streptomyces R61 DD-peptidase than is the analogous oxo beta-lactam. These results provide kinetic evidence for the existence of a catalytic oxyanion hole in these enzymes.
منابع مشابه
Kinetic study of interaction between BRL 42715, beta-lactamases, and D-alanyl-D-alanine peptidases.
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متن کاملBioorganic Chemistry
Both functional and structural studies of serine b-lactamases indicate the existence of an oxyanion hole at the active site with an important role in catalysis. The functional presence of the oxyanion hole is demonstrated by the previous observation that thiono-b-lactams are very poor substrates of b-lactamases (B. P. Murphy, and R. F. Pratt, 1988, Biochem. J. 256, 669–672) and in the present p...
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The low-Mr penicillin-binding protein (PBP)/DD-transpeptidase of Streptomyces K15 is synthesized in the form of a 291-amino acid-residue precursor possessing a cleavable 29-amino acid-residue signal peptide. Sequence-similarity searches and hydrophobic-cluster analysis show that the Streptomyces K15 enzyme, the Escherichia coli PBPs/DD-carboxy-peptidases 5 and 6, the Bacillus subtilis PBP/DD-ca...
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ورودعنوان ژورنال:
- The Biochemical journal
دوره 256 2 شماره
صفحات -
تاریخ انتشار 1988