Penicillin-sensitive DD-carboxypeptidases from Streptomyces strains R39 and K11
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چکیده
منابع مشابه
Peptide inhibitors of Streptomyces DD-carboxypeptidases.
1. Peptides that inhibit the dd-carboxypeptidases from Streptomyces strains albus G and R61 were synthesized. They are close analogues of the substrates of these enzymes. The enzymes from albus G and R61 strains are in general inhibited by the same peptides, but the enzyme from strain R39 differs considerably. 2. The two C-terminal residues of the peptide substrates and inhibitors appear to be ...
متن کاملInhibition of Streptococcus pneumoniae penicillin-binding protein 2x and Actinomadura R39 DD-peptidase activities by ceftaroline.
Although the rate of acylation of a penicillin-resistant form of Streptococcus pneumoniae penicillin-binding protein 2x (PBP2x) by ceftaroline is 80-fold lower than that of its penicillin-sensitive counterpart, it remains sufficiently high (k(2)/K = 12,600 M(-1) s(-1)) to explain the sensitivity of the penicillin-resistant strain to this new cephalosporin. Surprisingly, the Actinomadura R39 DD-...
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 کاملCrystal structure of the Actinomadura R39 DD-peptidase reveals new domains in penicillin-binding proteins.
Actinomadura sp. R39 produces an exocellular DD-peptidase/penicillin-binding protein (PBP) whose primary structure is similar to that of Escherichia coli PBP4. It is characterized by a high beta-lactam-binding activity (second order rate constant for the acylation of the active site serine by benzylpenicillin: k2/K = 300 mm(-1) s(-1)). The crystal structure of the DD-peptidase from Actinomadura...
متن کاملSite-directed mutagenesis of the Actinomadura R39 DD-peptidase.
The role of various residues in the conserved structural elements of the Actinomadura R39 penicillin-sensitive dd-peptidase has been studied by site-directed mutagenesis. Replacement of Ser-298 of the 'SDN loop' by Ala or Gly significantly decreased the kcat/Km value for the peptide substrate, but only by a factor of 15 and had little effect on the other catalytic properties. Mutations of Asn-3...
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ژورنال
عنوان ژورنال: Biochemistry
سال: 1972
ISSN: 0006-2960,1520-4995
DOI: 10.1021/bi00757a027