dd -Carboxypeptidase-Transpeptidase and Killing Site of β-Lactam Antibiotics in Streptomyces Strains R39, R61, and K11
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چکیده
منابع مشابه
Molecular weight and amino acid composition of the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61.
A procedure allowing the purification of milligram amounts of the exocellular dd-carboxypeptidase-transpeptidase from Streptomyces R61 to protein homogeneity (95% purity) is described. The isolated protein has a molecular weight of about 38000 and consists of one polypeptide chain. Its amino acid composition is presented.
متن کاملThe penicillin-binding site in the exocellular DD-carboxypeptidase-transpeptidase of Actinomadura R39.
Heat denaturation and Pronase degradation of the complex previously formed between benzylpenicillin and the exocellular DD-carboxypeptidase-transpeptidase of Actinomadura R39 yields a heptapeptide H-Leu-Pro-Ala-Ser-Asn-Gly-Val-OH, where the benzylpenicilloyl group is ester-linked to the serine residue. This linkage is very labile and its hydrolysis causes the release of benzylpenicilloate. In c...
متن کاملFluorescence and circular dichroism studies on the Streptomyces R61 DD-carboxypeptidase-transpeptidase. Penicillin binding by the enzyme.
The circular dichroism of the dd-carboxypeptidase-transpeptidase from Streptomyces R61 shows in the near u.v. a set of weak extrema at 289nm (positive) and at 282, 275 and 268nm (all negative). In the far u.v. it shows negative extrema at 217-218 and 208nm, crossover at 202nm and a positive maximum at about 194nm. The u.v. absorption of the enzyme shows it to contain tyrosine and tryptophan in ...
متن کاملDD-carboxypeptidase and peptidoglycan transpeptidase from Pseudomonas aeruginosa.
Peptidoglycan transpeptidase and dd-carboxypeptidase have been detected in isolated membranes of Pseudomonas aeruginosa. Cephalosporins and penicillins fail to inhibit the transpeptidase at concentrations as high as 100 mug/ml. dd-Carboxypeptidase, on the other hand, is sensitive to inhibition by beta-lactam antibiotics. The presence of dimethyl sulfoxide in the reaction mixture results in a tw...
متن کاملMechanism of action of DD-peptidases: role of asparagine-161 in the Streptomyces R61 DD-peptidase.
The role of residue Asn-161 in the interaction between the Streptomyces R61 DD-peptidase and various substrates or beta-lactam inactivators was probed by site-directed mutagenesis. The residue was successively replaced by serine and alanine. In the first case, acylation rates were mainly affected with the peptide and ester substrates but not with the thiol-ester substrates and beta-lactams. How...
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ژورنال
عنوان ژورنال: Antimicrobial Agents and Chemotherapy
سال: 1973
ISSN: 0066-4804,1098-6596
DOI: 10.1128/aac.3.2.181