References of "Frère, Jean-Marie"
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See detailDD-carboxypeptidase-transpeptidase and killing site of β-lactam antibiotics in Streptomyces strains R39, R61, and K11
Dusart, Jean; Marquet, Alberto; Ghuysen, Jean-Marie ULg et al

in Antimicrobial Agents and Chemotherapy (1973), 3(2), 181-187

Additional evidence is given that in Streptomyces strains R39, R61, and K11 the same enzyme performs dd-carboxypeptidase and transpeptidase activities and that this enzyme is the killing site of beta ... [more ▼]

Additional evidence is given that in Streptomyces strains R39, R61, and K11 the same enzyme performs dd-carboxypeptidase and transpeptidase activities and that this enzyme is the killing site of beta-lactam antibiotics. With strain R61, it was found that the exocellular enzyme has a sensitivity towards some antibiotics different from that of the membrane-bound enzyme. Under the growth conditions used in the present investigations, beta-lactamase activity was not involved in susceptibility to beta-lactam antibiotics. [less ▲]

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See detailPeptide inhibitors of Streptomyces DD-carboxypeptidases
Nieto, Manuel; Perkins, Harnold R.; Leyh-Bouille, Mélina et al

in Biochemical Journal (1973), 131(1), 163-171

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 ... [more ▼]

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 mainly responsible for the initial binding of the substrate to the enzymes from albus G and R61 strains. The side chain in the third residue from the C-terminus seems critical in inducing catalytic activity. 3. Experimental evidence is presented suggesting that the amide bond linking the two C-terminal residues has a cis configuration when bound to the enzymes from strains albus G and R61. 4. The peptide inhibitors are not antibiotics against the same micro-organisms. [less ▲]

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See detailDD-carboxypeptidases/Transpeptidases and Penicillin Action
Perkins, Harold R; Ghuysen, Jean-Marie ULg; Nieto, Manuel et al

in 1st International Congress for Bacteriology, Jerusalem, 2-7 September, 1973. Abstracts. Vol I. Symposia (1973)

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See detailStructure of the wall peptidoglycan of streptomyces R39 and the specificity profile of its exocellular DD-carboxypeptidase-transpeptidase for peptide acceptors
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina; Campbell, James N. et al

in Biochemistry (1973), 12(7), 1243-1251

Benzylpenicillin and cephaloridine reacted with the exocellular dd-carboxypeptidase–transpeptidase from Streptomyces R39 to form equimolar and inactive antibiotic–enzyme complexes. At saturation, the ... [more ▼]

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 antibiotic. Spectrophotometric studies showed that binding of cephaloridine and cephalosporin 87-312 to the enzyme caused opening of their β-lactam rings. Benzylpenicillin and cephalosporin 87-312 competed for the same site on the free enzyme, suggesting that binding of benzylpenicillin also resulted in the opening of its β-lactam ring. In Tris–NaCl–MgCl2 buffer at pH7.7 and 37°C, the rate constants for the dissociation of the antibiotic–enzyme complexes were 2.8×10−6, 1.5×10−6 and 0.63×10−6s−1 (half-lives 70, 130 and 300h) for benzylpenicillin, cephalosporin 87-312 and cephaloridine respectively. During the process, the protein underwent reactivation. The enzyme that was regenerated from its complex with benzylpenicillin was as sensitive to fresh benzylpenicillin as the native enzyme. With [14C]benzylpenicillin, the released radioactive compound was neither benzylpenicillin nor benzylpenicilloic acid. The Streptomyces R39 enzyme thus behaved as a β-lactam-antibiotic-destroying enzyme but did not function as a β-lactamase. Incubation at 37°C in 0.01m-phosphate buffer, pH7.0, and in the same buffer supplemented with sodium dodecyl sulphate caused a more rapid reversion of the [14C]benzylpenicillin–enzyme complex. The rate constants were 1.6×10−5s−1 and 0.8×10−4s−1 respectively. Under these conditions, however, there was no concomitant reactivation of the enzyme and the released radioactive compound(s) appeared not to be the same as before. The Streptomyces R39 enzyme and the exocellular dd-carboxypeptidase–transpeptidase from Streptomyces R61 appeared to differ from each other with regard to the topography of their penicillin-binding site. [less ▲]

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See detailPenicillin-sensitive DD-carboxypeptidases from Streptomyces strains R39 and K11
Leyh-Bouille, Mélina; Nakel, Marlies; Frère, Jean-Marie ULg et al

in Biochemistry (1972), 11(7), 1290-1298

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See detailTranspeptidase activity of Streptomyces D-alanyl-D carboxypeptidases
Pollock, J. J.; Ghuysen, Jean-Marie ULg; Linder, R. et al

in Proceedings of the National Academy of Sciences of the United States of America (1972), 69(3), 662-666

In the presence of N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-Ala as donor, and either D-[(14)C]alanine, [(14)C]-glycine, or meso-[(3)H]diaminopimelic acid as acceptor, the DD carboxypeptidases from ... [more ▼]

In the presence of N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-Ala as donor, and either D-[(14)C]alanine, [(14)C]-glycine, or meso-[(3)H]diaminopimelic acid as acceptor, the DD carboxypeptidases from Streptomyces R61 and R39 catalyze a transpeptidation reaction with the release of terminal D-alanine from the donor and the formation of either N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-[(14)C]Ala, N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-[(14)C] Gly, or N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala-D-meso- [(3)H]diaminopimelic acid. The reaction appears to be a true transpeptidation, and is not simply a "reversal of hydrolysis". Transpeptidation is inhibited by pencillin at concentrations that inhibit hydrolysis (carboxypeptidase action) of the donor peptide. There are differences in the specificity profiles of the Streptomyces enzymes for acceptor molecules:only the R61 enzyme used [(14)C]Gly-Gly as acceptor; transfer of N(alpha),N(epsilon)-diacetyl-L-Lys-D-Ala to this acceptor resulted in the formation of N(alpha),N(epsilon)-diacetyl-Lys-D-Ala-[(14)C] Gly-Gly, with the synthesis of a (D-Ala-Gly) peptide bond in an endoposition. [less ▲]

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See detailThe Streptomyces DD-carboxypeptidase-transpeptidase system as a model for the study of penicillin action
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina; Frère, Jean-Marie ULg et al

in Pratesi, P. (Ed.) Medicinal Chemistry : Special contributions - Milan 1972 (1972)

A new model for the transpeptidation reaction involved in the biosynthesis of the bacterial wall peptidoglycan and for its inhibition by penicillin is proposed. This model is in open conflict with the ... [more ▼]

A new model for the transpeptidation reaction involved in the biosynthesis of the bacterial wall peptidoglycan and for its inhibition by penicillin is proposed. This model is in open conflict with the hypotheses previously postulated. It rests upon the demonstration that 1) carboxypeptidase and transpep-tidase activities are performed by the same enzyme, 2) inhibition of both activities by penicillin is carried out in the absence of irreversible acylation of the protein, 3) the enzyme contains multiple sites some of which are involved in regulation, 4) penicillin does not act as a structural analogue of the donor peptide involved in transpeptidation but may act at the level of regulatory site(s). [less ▲]

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