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See detailThe peptidoglycan crosslinking enzyme system in Streptomyces R61, K15 and rimosus. Immunological studies
Nguyen-Distèche, Martine ULg; Frère, Jean-Marie ULg; Dusart, Jean et al

in European Journal of Biochemistry (1977), 81(1), 29-32

The exocellular DD-carboxypeptidases from Streptomyces R61, K 15, the lysozyme-releasable DD-carboxypeptidases from Streptomyces R61, K15 and rimosus, and the membrane-bound DD-carboxypeptidase of ... [more ▼]

The exocellular DD-carboxypeptidases from Streptomyces R61, K 15, the lysozyme-releasable DD-carboxypeptidases from Streptomyces R61, K15 and rimosus, and the membrane-bound DD-carboxypeptidase of Streptomyces K15 are immunologically related to each other. [less ▲]

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See detailThe concept of the penicillin target from 1965 until today. The thirteenth marjory stephenson memorial lecture
Ghuysen, Jean-Marie ULg

in Journal of General Microbiology (1977, July 01), 101(1), 13-33

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See detailThe exchange reaction of peptides R-D-alanyl-D-alanine with D-[14C]alanine to R-D-alanyl-D-[14C]alanine and D-alanine, catalysed by the membranes of Streptococcus faecalis ATCC 9790
Coyette, Jacques; Ghuysen, Jean-Marie ULg; Perkins, Harold R.

in European Journal of Biochemistry (1977), 75(1), 225-229

Under alkaline conditions, the membrane-bound DD-carboxypeptidase of Streptococcus faecalis ATCC 9790 catalyses exchange reactions in which the X-L-R3-D-Ala moiety of peptides of the type X-L-R3-D-Ala-D ... [more ▼]

Under alkaline conditions, the membrane-bound DD-carboxypeptidase of Streptococcus faecalis ATCC 9790 catalyses exchange reactions in which the X-L-R3-D-Ala moiety of peptides of the type X-L-R3-D-Ala-D-Ala is transferred to simple amino compounds such as D-alanine, glycine and glycyl-glycine. The enzyme system is unable, however, to catalyse complex reactions that would simulate the natural transpeptidation reaction. [less ▲]

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See detailInteractions between beta-lactam antibiotics and isolated membranes of Streptococcus faecalis ATCC 9790
Coyette, Jacques; Ghuysen, Jean-Marie ULg; Binot, Françoise ULg et al

in European Journal of Biochemistry (1977), 75(1), 231-239

The DD-carboxypeptidase-exchange membrane-bound enzyme in Streptococcus faecalis ATCC 9790 reacts with beta-lactam antibiotics to form complexes with rather long half-lives. Depending upon the antibiotic ... [more ▼]

The DD-carboxypeptidase-exchange membrane-bound enzyme in Streptococcus faecalis ATCC 9790 reacts with beta-lactam antibiotics to form complexes with rather long half-lives. Depending upon the antibiotic, the second-order rate constants for complex formation range from 0.75-560 M-1 S-1 (at 37 degrees C and in water) and the first-order rate constants for complex breakdown range from 1.3 to 26 x 10(-5) s-1 (at 37 degrees C and in 5 mM phosphate buffer pH 7.5). There are about 30 pmol of DD-carboxypeptidase-exchange enzyme per mg of membrane protein. The degradation products arising from benzylpenicillin are phenylacetylglycine and probably N-formyl-D-penicillamine. Isolated membranes also contain other penicillin binding sites (about 70 pmol/mg membrane protein). That part of benzylpenicillin which reacts with at least some of these latter sites is slowly degraded into penicilloic acid. Normal functioning of the DD-carboxypeptidase-exchange membrane-bound enzyme is important, if not essential, for cell growth. With the beta-lactam antibiotics tested inhibition of cell growth is mainly related to the rates of formation of the inactive enzyme-antibiotic complexes. The relationship, however, is not a direct one probably due to the competitive effect exerted by the other penicillin binding sites. [less ▲]

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See detailBiosynthèse de la paroi bactérienne
Tinelli, Regina; Ghuysen, Jean-Marie ULg

in Bulletin de l'Association des Anciens Elèves de l’Institut Pasteur [=Bulletin de l'AAEIP] (1977), 71

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See detailBiosynthesis and assembly of bacterial cell walls
Ghuysen, Jean-Marie ULg

in Poste, George; Nicolson, Garth L (Eds.) The synthesis, assembly and turnover of celle surface components. (1977)

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See detailThe peptidoglycan crosslinking enzyme system in Streptomyces strains R61, K15 and rimosus. Exocellular, lysozyme-releasable and membrane-bound enzymes.
Leyh-Bouille, Mélina; Dusart, Jean; Nguyen Van, Martine ULg et al

in European Journal of Biochemistry (1977), 81(1), 19-28

The DD-carboxypeptidase (I)-transpeptidase (II) system in Streptomyces strain K15 consists of: (1) a membrane-bound II capable of performing low I activity; and (2) a set of I: (a) membrane-bound, (b ... [more ▼]

The DD-carboxypeptidase (I)-transpeptidase (II) system in Streptomyces strain K15 consists of: (1) a membrane-bound II capable of performing low I activity; and (2) a set of I: (a) membrane-bound, (b) lysozyme-releasable, and (c) exocellular, having low II activities in aq. media and at low acceptor concns. The I are related to each other and may belong to the same pathway leading to enzyme excretion. A similar system occurs in Streptomyces strain R61 except that the membrane-bound I activity is low when compared with the membrane-bound II activity. In S. rimosus, the system consists almost exclusively of the membrane-bound II and the levels of membrane-bound, lysozyme-releasable, and exocellular I are very low. [on SciFinder(R)] [less ▲]

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See detailLe récepteur de la penicilline chez les bactéries
Ghuysen, Jean-Marie ULg

in Bulletin de l'Académie Royale de Médecine de Belgique (1977), 132(1), 101-108

The β-lactam antibiotics are both substrates and inhibitors of the DD-carboxypeptidase-transpeptidase enzyme system involved in the closure of the interpeptide bridges during the biosynthesis of the wall ... [more ▼]

The β-lactam antibiotics are both substrates and inhibitors of the DD-carboxypeptidase-transpeptidase enzyme system involved in the closure of the interpeptide bridges during the biosynthesis of the wall peptidoglycan in bacteria. [less ▲]

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See detailPenicillin-Sensitive Enzymes of Peptidoglycan Metabolism
Ghuysen, Jean-Marie ULg

in Critical Reviews in Microbiology (1977)

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See detailFate of thiazolidine ring during fragmentation of penicillin by exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61
Frère, Jean-Marie ULg; Ghuysen, Jean-Marie ULg; Vanderhaeghe, Hubert et al

in Nature (1976), 260(5550), 451-454

LIKE various beta-lactamases, acylases and esterases1, the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61 degrades benzylpenicillin and other beta-lactam antibiotics2-4. The R61 enzyme ... [more ▼]

LIKE various beta-lactamases, acylases and esterases1, the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces R61 degrades benzylpenicillin and other beta-lactam antibiotics2-4. The R61 enzyme, however, markedly differs from the other penicillin-degrading enzymes in causing fragmentation of the penicillin nucleus. By using 8-14C-benzylpenicillin (benzyl labelled) as substrate, one of the fragments produced was shown to be 14C-phenylacetylglycine5. The reaction with the R61 enzyme is also peculiar in that it is a slow process. This is because of the long half life of the stoichiometnc complex transitorily formed between the antibiotic and the enzyme. Thus, for example, the value of the half life for the complex formed with benzylpenicillin is 80 min in 10 mM phosphate buffer (pH 7.0) and at 37 °C. As breakdown of the complex proceeds, however, phenylacetylglycine (when benzylpenicillin is used as substrate) is released and the enzyme concomitantly recovers its ability to bind penicillin. We have now characterised the fragment (hereby designated as the Y product) arising from the thiazolidine ring of penicillin as a result of the fragmentation of the antibiotic molecule by the R61 enzyme. [less ▲]

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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 detailPréparation enzymatique de peptides du type (L)meso-diaminopimélyl(L)-D-Ala[14C]: par réactions d'échange entre les peptides correspondants non radioactifs et la D-alanine [14C]
Arminjon, François; Guinand, Micheline; Michel, Georges et al

in Biochimie (1976), 58(10), 1167-1172

Membrane bound LD-transpeptidase of Streptococcus faecalis ATCC 9790 was used to catalyse transpeptidation reactions between non radioactive peptide donors of the general type: L-Ala-D-Glu (L)meso-A2pm(L ... [more ▼]

Membrane bound LD-transpeptidase of Streptococcus faecalis ATCC 9790 was used to catalyse transpeptidation reactions between non radioactive peptide donors of the general type: L-Ala-D-Glu (L)meso-A2pm(L)-D-Ala and D-(14C) alanine acceptor. The presence of one or two amide residues on the carboxyl groups of glutamic acid and meso-diaminopimelic acid increases the transfer reactions and subsequently the yield in radioactive peptides L-Ala-D-Glu (L)meso-A2pm(L)-D-(14C) Ala. [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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