Purification and properties of the exocellular β-lactamase of a Actinomadura strain R39 [PDF]
Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1982 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 ...
Duez, Colette +5 more
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Nucleotide sequence of the gene encoding the active-site serine β-lactamase fromActinomaduraR39 [PDF]
FEMS Microbiology Letters, 1989 The gene encoding the extracellular, active-site serine beta-lactamase of Actinomadura R39, previously cloned into Streptomyces lividans, has the information for the synthesis of a 304 amino acid protein, the amino terminal region of which has the characteristic features of a signal peptide.
Houba, Simone +6 more
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Site-directed mutagenesis of the Actinomadura R39 DD-peptidase [PDF]
Biochemical Journal, 1997 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 ...
G H, Zhao +7 more
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The penicillin-binding site in the exocellular
Biochemical Journal, 1981 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.
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Binding of β-lactam antibiotics to the exocellular
Biochemical Journal, 1974 Benzylpenicillin and cephaloridine reacted with the exocellular dd-carboxypeptidase–transpeptidase from Streptomyces R39 to form equimolar and inactive antibiotic–enzyme complexes. At saturation, the molar ratio of chromogenic cephalosporin 87-312 to enzyme was 1.3:1, but this discrepancy might be due to a lack of accuracy in the measurement of the ...
Jean-Marie Frère +4 more
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Kinetics of Reactions of the Actinomadura R39
Biochemistry, 2010 The Actinomadura R39 DD-peptidase catalyzes the hydrolysis and aminolysis of a number of small peptides and depsipeptides. Details of its substrate specificity and the nature of its in vivo substrate are not, however, well understood. This paper describes the interactions of the R39 enzyme with two peptidoglycan-mimetic substrates 3-(D-cysteinyl ...
Adediran, S. A. +4 more
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Exocellular β-Lactamases of Streptomyces albus G and Strains R39 and K11 [PDF]
Antimicrobial Agents and Chemotherapy, 1973 The β-lactamases excreted by the highly benzylpenicillin-susceptible Streptomyces strain R39 and the highly benzylpenicillin-resistant Streptomyces albus G were isolated and purified. Neither β-lactamase exhibited dd -carboxypeptidase activity. Both were anionic at
Johnson, Kenneth +3 more
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Inhibition of Streptococcus pneumoniae Penicillin-Binding Protein 2x and Actinomadura R39 DD-Peptidase Activities by Ceftaroline [PDF]
Antimicrobial Agents and Chemotherapy, 2013 ABSTRACT 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
Zervosen, Astrid +2 more
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Mode of interaction between β-lactam antibiotics and the exocellular DD-carboxypeptidase–transpeptidase from Streptomyces R39. [PDF]
Biochemical Journal, 1976 The exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R39 is inhibited by beta-lactam antibiotics according to the same general scheme of reaction as the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61. However, the values for the kinetic constants involved in the reaction are very different for the two enzymes and ...
Fuad, Noha +4 more
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Cloning and amplified expression in Streptomyces lividans of the gene encoding the extracellular β-lactamase of Actinomadura R39 [PDF]
Biochemical Journal, 1989 By using the promoter-probe plasmid pIJ424, genomic DNA fragments of Actinomadura R39 were shown to have promoter activity in Streptomyces lividans. The same 100-200-copy-number plasmid was used to clone in S. lividans TK24, the gene that encodes the Actinomadura R39 beta-lactamase. Gene cloning resulted in an amplified expression of the beta-lactamase
Fraipont, Claudine +6 more
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