References of "Frère, Jean-Marie"
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See detail[51] Exocellular dd-carboxypeptidases-transpeptidases from Streptomyces
Frère, Jean-Marie ULg; Leyh-Bouille, Mélina; Ghuysen, Jean-Marie ULg et al

in Lorand, Laszlo (Ed.) Part B: Proteolytic Enzymes (1976)

Strains R39 and R61 are soil isolates. Their designations are arbitrary. In strain R39, the cross-link between the peptide units of the wall peptidoglycan extends from the C-terminal D-alanine of one unit ... [more ▼]

Strains R39 and R61 are soil isolates. Their designations are arbitrary. In strain R39, the cross-link between the peptide units of the wall peptidoglycan extends from the C-terminal D-alanine of one unit to the amino group at the D-center of meso-diaminopimelic acid of another unit (peptidoglycan of chemotype I). The interpeptide bond is in position to a free carboxyl group. In strain R61, the cross-link extends from a C-terminal D-alanine of a peptide unit to a glycine residue attached to the amino group of LL-diaminopimelic acid of another peptide unit (peptidoglycan of chemotype II). The exocellular DD carboxypeptidases-transpeptidases produced by both strains catalyze hydrolysis, react with β-lactam antibiotics. This chapter explains the assay methods for DD-Carboxypeptidase activity like the standard reaction, chemical estimation of free Alanine, as well as, assay method for β-Lactamase. It also discusses the Excretion of DD-Carboxypeptidase-Transpeptidase and β -Lactamase by Streptomyces R39, Excretion of DD-Carboxypeptidase-Transpeptidase and β-Lactamase by Streptomyces R61, purification of the DD-Carboxypeptidase-Transpeptidase from Streptomyces R39 (for 500 Liters of Culture Fluid), Purification of the DD-Carboxypeptidase-Transpeptidase from Streptomyces R61 (for 400 Liters of Culture Fluid), Physicochemical Properties of DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61, Interaction between DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61 and β-Lactam Antibiotics , Titration of DD-Carboxypeptidases-Transpeptidases from Streptornyces R39 and R61 by β-Lactam Antibiotics, Hydrolysis Reactions Catalyzed by the DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61, Concomitant Hydrolysis and Transfer Reactions Involving Distinct Donor and Acceptor Peptides, Catalyzed by the DD-Carboxypeptidases-Transpeptidases from Streptonayces R39 and R61, Concomitant Hydrolysis and Transfer Reactions Catalyzed by the DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61 and in Which the Same Peptide Acts as Donor and Acceptor and Inhibition of DD-Carboxypeptidases-Transpeptidases from Streptomyces R39 and R61 by β-Lactam Antibiotics in the Presence of Substrates. Copyright © 1976 Published by Elsevier Inc. [less ▲]

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See detailMode of interaction between β-lactam antibiotics and the exocellular DD-carboxypeptidase--transpeptidase from Streptomyces R39
Fuad, Noha; Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg et al

in Biochemical Journal (1976), 155(3), 623-629

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 ... [more ▼]

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 provide an explanation for the observation that the R39 enzyme is more sensitive to beta-lactam antibiotics than the R61 enzyme. Further, particular beta-lactams influence the kinetic constants to different extents depending on the source of the enzyme, so that a physical basis for the spectrum of antibiotic activity against particular enzyme systems is provided. [less ▲]

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See detailDegradation of benzylpenicillin by the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R 61
Frère, Jean-Marie ULg; Adriaens, P.; Degelaen, J. et al

in Archives Internationales de Physiologie et de Biochimie (1975), 83(5), 905-907

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See detailKinetics of interaction between the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61 and beta-lactam antibiotics. A choice of models
Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg; Iwatsubo, Motohiro

in European Journal of Biochemistry (1975), 57(2), 343-351

The simplest model for the interaction between the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61 and beta-lactam antibiotics involves the three following steps: (a) the formation of ... [more ▼]

The simplest model for the interaction between the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61 and beta-lactam antibiotics involves the three following steps: (a) the formation of a reversible equimolar enzyme - antibiotic complex; (b) the irreversible transformation of this complex into a modified enzyme - antibiotic complex; and (c) the breakdown of this latter complex and the concomitant release of a regenerated enzyme and a modified antibiotic molecule. The dissociation constant for step 1 and the rate constants for steps 2 and 3 were measured with various beta-lactam antibiotics. With antibiotic such as benzylpenicillin, which behaves as a good 'substrate', steps 1 and 2 occur at enzymic velocities, whereas step 3 occurs at a very low velocity and hence is responsible for the low efficiency of the overall process. [less ▲]

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See detailInteraction between the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61, substrate and beta-lactam antibiotics. A choice of models
Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg; Perkins, Harold R

in European Journal of Biochemistry (1975), 57(2), 353-359

The interaction between the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61 and beta-lactam antibiotics is a multistep process during which a rather stable enzyme - antibiotic complex ... [more ▼]

The interaction between the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61 and beta-lactam antibiotics is a multistep process during which a rather stable enzyme - antibiotic complex is formed. This mechanism of interaction is compatible with Lineweaver-Burk plots that are typical of a competitive inhibition of the hydrolysis of the peptide donor by the antibiotic. In fact, however, the same Lineweaver-Burk plots can be obtained on the basis of a non-competitive type of inhibition. At present, a choice between the two models cannot be made. [less ▲]

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See detailA donor-acceptor substrate of the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61
Zeiger, Allen R; Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg et al

in FEBS Letters (1975), 52(2), 221-225

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See detailBeta-lactamases (Actinomycetes species)
Johnson, Kenneth; Duez, Colette ULg; Frère, Jean-Marie ULg et al

in Methods in Enzymology (1975), XLIII

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See detailInteraction between beta-lactam antibiotics and exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61
Frère, Jean-Marie ULg; Leyh-Bouille, Mélina; Ghuysen, Jean-Marie ULg et al

in European Journal of Biochemistry (1974), 50(1), 203-214

On the basis of steady-state kinetics, inhibition of the exocellular dd-carboxypeptidase-trans-peptidase of Streptomyces R61 by β-lactam antibiotics was competitive with regard to the donor substrate ... [more ▼]

On the basis of steady-state kinetics, inhibition of the exocellular dd-carboxypeptidase-trans-peptidase of Streptomyces R61 by β-lactam antibiotics was competitive with regard to the donor substrate. However, the complexes formed between the Streptomyces R61 enzyme and various β-lactam antibiotics were relatively stable, exhibiting half-lives of 40 to 80 min at 37°C and neutral pH. During breakdown of the complexes the protein underwent reactivation, whereas the released antibiotic molecule was chemically altered. With [14C]benzylpenicillin, the released compound was neither benzylpenicillin nor benzylpenicilloic acid. The properties of the Streptomyces R61 enzyme β-lactam antibiotic complexes were compared with those of the complexes formed between the same antibiotics and either the membrane-bound transpeptidase from Streptomyces R61 or the exocellular dd-carboxypeptidase-transpeptidase of Streptomyces R39. [less ▲]

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See detailMolecular weight, amino acid composition and physicochemical properties of the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R39
Frère, Jean-Marie ULg; Moreno, Ramon; Ghuysen, Jean-Marie ULg

in Biochemical Journal (1974), 143(1), 233-240

The exocellular dd-carboxypeptidase-transpeptidase from Streptomyces R39 was purified to protein homogeneity and in milligram amounts. The isolated enzyme consisted of one polypeptide chain of molecular ... [more ▼]

The exocellular dd-carboxypeptidase-transpeptidase from Streptomyces R39 was purified to protein homogeneity and in milligram amounts. The isolated enzyme consisted of one polypeptide chain of molecular weight about 53300. Its amino acid composition and several physicochemical properties were determined and compared with those of the exo-cellular dd-carboxypeptidase-transpeptidase from Streptomyces R61. [less ▲]

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See detailThe penicillin receptor in Streptomyces
Ghuysen, Jean-Marie ULg; Leyh-Bouille, M.; Frère, Jean-Marie ULg et al

in Annals of the New York Academy of Sciences (1974), 235

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See detailComment la Pénicilline tue les bactéries
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina; Frère, Jean-Marie ULg et al

in Annales de Microbiologie (1974), 125 B(2), 209-210

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See detailThe penicillin Target in Bacteria
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina; Frère, Jean-Marie ULg et al

in Spencer, B. (Ed.) Industrial Aspects of Biochemistry (FEBS Proceedings) (1974)

The bacterial target of beta-lactam antibiotics consists of a set of multiple, membrane-bound receptors. Some of them have been characterized as DD-carboxypeptidases. The DD-carboxypeptidases catalyse the ... [more ▼]

The bacterial target of beta-lactam antibiotics consists of a set of multiple, membrane-bound receptors. Some of them have been characterized as DD-carboxypeptidases. The DD-carboxypeptidases catalyse the opening of amide bonds and transfer the carbonyl carbon to an exogenous nucleophile, and are specifically designed to operate on the D-Ala-D-Ala linkageof L-R-D-Ala-D-Ala terminated peptides (where R is most often a diamino acid residue). The R61, R39 and several Bacilli DD-carboxypeptidases are known to be serine-enzymes and the G DD-carboxypeptidase has been characterized as a metallo (Zn ions) enzyme. Both the R61 and the G enzymes have been crystallized. In turn, the S. faecalis 43,000-Mr DD-carboxypeptidase, which is inhibited by low dose levels of pCMB, might be a thiol-enzyme. The goal pursued is the understanding of the mechanistic properties and functioning of the active centers of the DD-carboxypeptidases at the molecular and atomic levels. The research program involves 1) further characterization of the S. faecalis enzyme (which can be obtained in a water-soluble form); 2) isolation of various Streptomyces membrane-bound enzymes in a truly water-soluble form; 3) sequencing of the G and R61 enzymes; 4) the 2.8 A structure analysis of the G enzyme. (A similar study is conducted by Dr. J.R. Knox at the University of Connecticut, on the R61 enzyme, which enzyme is prepared and purified in this laboratory and then sent to Storrs); 5) conformational studies and quantitative structure activity relationships (QSAR). Source du résumé : http://www.researchcrossroads.org/index.php?view=article&id=50%3Agrant-details&option=com_content&Itemid=64&grant_id=4296130 [less ▲]

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See detailBinding of beta-lactam antibiotics to the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R39
Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg; Reynolds, Peter E. et al

in Biochemical Journal (1974), 143(1), 241-249

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 beta-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 beta-lactam ring. In Tris-NaCl-MgCl(2) buffer at pH7.7 and 37 degrees C, the rate constants for the dissociation of the antibiotic-enzyme complexes were 2.8x10(-6), 1.5x10(-6) and 0.63x10(-6)s(-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 [(14)C]benzylpenicillin, the released radioactive compound was neither benzylpenicillin nor benzylpenicilloic acid. The Streptomyces R39 enzyme thus behaved as a beta-lactam-antibiotic-destroying enzyme but did not function as a beta-lactamase. Incubation at 37 degrees 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 [(14)C]benzylpenicillin-enzyme complex. The rate constants were 1.6x10(-5)s(-1) and 0.8x10(-4)s(-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 detailKinetics of concomitant transfer and hydrolysis reactions catalysed by the exocellular DD-carboxypeptidase-transpeptidase of streptomyces R61
Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg; Perkins, Harnold R. et al

in Biochemical Journal (1973), 135(3), 483-492

When Ac(2)-l-Lys-d-Ala-d-Ala and either meso-diaminopimelic acid or Gly-l-Ala are exposed to the exocellular dd-carboxypeptidase-transpeptidase of Streptomyces R61, transpeptidation reactions yielding Ac ... [more ▼]

When Ac(2)-l-Lys-d-Ala-d-Ala and either meso-diaminopimelic acid or Gly-l-Ala are exposed to the exocellular dd-carboxypeptidase-transpeptidase of Streptomyces R61, transpeptidation reactions yielding Ac(2)-l-Lys-d-Ala-(d)-meso- diaminopimelic acid and Ac(2)-l-Lys-d-Ala-Gly-l-Ala occur concomitantly with the hydrolysis of the tripeptide into Ac(2)-l-Lys-d-Ala. The proportion of the enzyme activity which can be channelled in the transpeptidation and the hydrolysis pathways depends upon the pH and the polarity of the environment. Transpeptidation is favoured both by increasing the pH and by decreasing the water content of the reaction mixtures. Kinetics suggest that the reactions proceed through an ordered mechanism in which the acceptor molecule (meso-diaminopimelic acid or Gly-l-Ala) binds first to the enzyme. Both acceptors behave as non-competitive inhibitors of the hydrolysis pathway. Transpeptidation is inhibited by high concentrations of Gly-l-Ala but not by high concentrations of meso-diaminopimelic acid. The occurrence on the enzyme of an additional inhibitory binding site for Gly-l-Ala is suggested. [less ▲]

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See detailMolecular weight and amino acid composition of the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61
Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg; Perkins, Harnold R. et al

in Biochemical Journal (1973), 135(3), 463-468

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 ... [more ▼]

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. [less ▲]

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See detailFluorescence and circular dichroism studies on the Streptomyces R61 DD-carboxypeptidase-transpeptidase. Penicillin binding by the enzyme
Nieto, Manuel; Perkins, Harnold R.; Frère, Jean-Marie ULg et al

in Biochemical Journal (1973), 135(3), 493-505

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 ... [more ▼]

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 approx. 3.4:1 ratio. The enzyme is fluorescent with a maximum emission at 318-320nm. The near-u.v. circular dichroism of the protein is extensively affected by binding of penicillin G, but the far u.v. is unaffected. Binding of the antibiotic also causes quenching of the fluorescence of the enzyme. The latter effect has been used to study the binding of penicillin G to the enzyme and the influence exerted upon it by salts, denaturants and peptide substrates and inhibitors. High-affinity binding of penicillin appears to be comparatively slow and reversible, and can occur under conditions in which the protein is enzymically inactive. The thermal denaturation of the enzyme in guanidinium chloride at pH7 is affected by binding of the antibiotic. The presence of even large concentrations of beta-mercaptoethanol neither impaired the activity of the enzyme nor prevented its inhibition by penicillin G or cephalosporin C. A new hypothesis for the molecular mechanism of the interaction of the enzyme with penicillin is proposed. [less ▲]

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See detailStreptomyces DD-carboxypeptidases as transpeptidases. The specificity for amino compounds acting as carboxyl acceptors
Perkins, Harnold R.; Nieto, Manuel; Frère, Jean-Marie ULg et al

in Biochemical Journal (1973), 131(4), 707-718

The ability of the water-soluble dd-carboxypeptidases of Streptomyces strains albus G, R61, K11 and R39 to perform transpeptidation was studied. The donor was diacetyl-l-lysyl-d-alanyl-d-alanine, and a ... [more ▼]

The ability of the water-soluble dd-carboxypeptidases of Streptomyces strains albus G, R61, K11 and R39 to perform transpeptidation was studied. The donor was diacetyl-l-lysyl-d-alanyl-d-alanine, and a whole range of amino acids, peptides and structurally related amino compounds were tested for acceptor function. No compound tested was an acceptor for the enzyme from strain albus G whereas the enzymes from strains R61 and K11 could utilize with varying efficiency a wide range of substances including peptides with N-terminal glycine or d-alanine, omega-amino acids, aminohexuronic acids, 6-aminopenicillanic acid and d-cycloserine. Certain peptides, when present in higher concentration, inhibited the transpeptidation observed at lower concentration. The enzyme from strain R39 would not use any dipeptide as an acceptor, but a few compounds that were not glycine or alpha-amino acids of the d-configuration did function thus. These were d-cycloserine and the lactams of meso- or racemic-diaminoadipic acid. [less ▲]

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