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Biochimica et Biophysica Acta | 1980

Kinetic studies on the action of Mucor pusillus, Mucor miehei acid proteases and chymosins A and B on a synthetic chromophoric hexapeptide

Patrice Martin; M.N. Raymond; Evanghelos Bricas; B.Ribadeau Dumas

The action of two milk-clotting fungal proteases from Mucos pusillus and Mucor miehei and of chymosins A and B on the hexapeptide, Leu-Ser-Phe(NO2)-Nle-Ala-Leu-OMe, and on kappa-casein were studied. The effects of pH and temperature on the initial rates of hydrolysis of the hexapeptide were examined. Crystalline chymosin and M. pusillus protease exhibited optimal activities around 49 and 55 degrees C, respectively, whereas the optimum temperature for M. miehei protease is higher than 63 degrees C. The optimum pH was about 4.7 for both fungal proteases whereas chymosin A and chymosin B exhibited optimal activities around 4.2 and 3.7, respectively. Kinetic parameters were then determined under optimal conditions and/or at pH 4.7. Fungal proteases had kcat/Km ratios that were similar to each other and that were significantly greater than the ratios obtained for the chymosins. Nevertheless, chymosins had much greater clotting activities towards kappa-casein relative to their proteolytic activities towards the synthetic peptide.


Biochimica et Biophysica Acta | 1975

13C-nuclear magnetic resonance studies of 85% 13C-enriched amino acids and small peptides: pH effects on the chemical shifts, coupling constants, kinetics of cis-trans isomerisation and conformation aspects

Serge Fermandjian; S. Tran-Dinh; J. Šavrda; E. Sala; R. Mermet-Bouvier; Evanghelos Bricas; Pierre Fromageot

The 13C chemical shifts of several 85% 13C-enriched amino acids and small peptides were studied as a function of pH. The results show that the chemical shifts of carbon atoms of ionizable groups vary significantly within the zone of their pK. Generally with the pH GOING FROM 7 to 1 all the deltaC are shifted more or less upfield with the exception of the carbonyl group carbon of the second last residue which is shifted slightly downfield. This suggests the formation of an hydrogen bond at acid pH involving in a seven-membered ring the C=O in question and the COOH terminal. The percentage of cis and trans conformers of glycyl-L-proline and glycyl-L-prolylglycine were studied as a function of pH. The trans form is always preponderant whatever the pH. The accessibility of the carbonyl group to protonation of the proline residue strongly influences the cis-trans equilibrium. Thus, with the pH varying from 7 to 1, the trans isomer changes from 61 to 85% for glycyl-L-proline and only from 77 to 80% for glycyl-L-prolylglycine. The proton NMR studies underline the important differences existing between the two molecular forms of glycyl-L-proline. The cis conformation is characterized with regard to the trans form by the non-equivalence of the alpha-protons of the glycine residue, by a lower pK(1) and by a larger deltadeltaHalpha of the proline residue as a function of pH. These results could suggest an end-to-end interaction in the cis form of the glycyl-L-proline molecule. The 13C-13C coupling constants were also studied as a function of pH. The results show that J(Co-Calpha) of a C-terminal residue, varying from 5 to 6 Hz and reflecting thhe pK of the carboxylate group, is a linear function of delta(Co) and delta(Calpha) as in the case of the amino acids. The total variation of the electron density of those two carbons in an amino acid is approximately 40% weaker than in a C-terminal residue. The charge distribution along the Calpha-C(o) bond, however, is practically the same in both cases. Finally the ratios of the conversion rate constants of the two isomers cis-trans of glycyl-proline were calculated at different pH values; the relations between the isomer percentages and delta(Co), delta(Calpha) on the one hand and the J(Co-Calpha) on the other were established.


Biochimica et Biophysica Acta | 1982

High affinity binding sites on plasma membrane obtained from the lymphoblastoid cultured 1301 cell line for highly radioactive serum thymic factor

Louis Noël Gastinel; Jean-Marie Pleau; Mireille Dardenne; André Sasaki; Evanghelos Bricas; Jean-Louis Morgat; Jean-François Bach

The interaction of the synthetic serum thymic factor (FTS, facteur thymique sérique) with a plasma membrane preparation of human T lymphocytes from the lymphoblastoid T cell line 1301 was studied using 3H-labelled FTS (specific activity 120 Ci/mmol). The binding is temperature dependent and function of the concentration of both 3H-labelled FTS and membrane proteins. At 37 degrees C, using 1 nM of 3H-labelled FTS as steady state is observed within 80 min. The binding is reversible, specific and saturable. Scatchard analysis reveals the existence of at least two binding sites with respective Kd of the order of 0.516 +/- 0.2 nM and 110 +/- 27.8 nM with concentration of 0.186 +/- 0.045 pmol and 2.026 +/- 0.367 pmol per mg of membrane protein.


Biochimie | 1976

Synthesis of the monomer and dimer peptide fragments of the Micrococcus lysodeikticus cell wall peptidoglycan

M. Mulliez; Didier Blanot; J. Savrda; Evanghelos Bricas

Three branched peptides, namely pentapeptide A and the two decapeptides B and C corresponding respectively to the monomer and the two dimer peptide fragments of the M. lysodeikticus cell wall peptidoglycan, were synthetized by adequate methods of peptide synthesis in homogeneous phase. The synthetized peptides showed the same electrophoretic and chromatographic behavior as the natural peptide fragments. Only decapeptide B was hydrolysed by the Myxobacter AL-1 protease by cleavage of the D-Ala-L-Ala bond and inversely, only decapeptide C was digested by the Streptomyces albus ML endopeptidase by cleavage of the D-Ala-epsilon-Lys linkage. In both enzymatic hydrolyses the pentapeptide monomer was formed.


International Journal of Peptide and Protein Research | 2009

Synthesis of analogs of the serum thymic nonapeptide, "facteur thymique serique" (FTS). Part II.

Didier Blanot; Jean Martinez; Geneviève Auger; Evanghelos Bricas


Archive | 1978

Novel polypeptides having thymic activity or an antagonistic activity and processes for their synthesis

Jean-Francois Bach; Mireille Dardenne; Jean-Marie Pleau; Jean Hamburger; Evanghelos Bricas; Jean Martinez; Didier Blanot; Geneviève Auger


Biological Chemistry | 1982

Synthesis of an Immunogenic Conjugate and of Two 125I-Labelled Derivatives of the “Facteur Thymique Serique”

Geneviève Auger; Didier Blanot; Evanghelos Bricas; Jean-Marie Pleau; Mireille Dardenne; Jean-François Bach


Archive | 1978

Neue polypeptide mit thymusaktivitaet oder antagonistischer aktivitaet und verfahren zu ihrer herstellung New aktivitaet with thymic polypeptide or antagonistic and process for their production

Jean-Francois Bach; Mireille Dardenne; Jean-Marie Pleau; Jean Hamburger; Evanghelos Bricas; Jean Marinez; Didier Blanot; Geneviève Auger


Archive | 1978

New thymic polypeptides or antagonistic activity and process for their manufacture

Jean-Francois Bach; Mireille Dardenne; Jean-Marie Pleau; Jean Hamburger; Evanghelos Bricas; Jean Marinez; Didier Blanot; Geneviève Auger


Archive | 1978

POLYPEPTIDES AND PROCESSES FOR THE SYNTHESIS THEREOF

Jean-Francois Bach; Mireille Dardenne; Jean-Marie Pleau; Jean Hamburger; Evanghelos Bricas; Jean Martinez; Didier Blanot; Geneviève Auger

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Didier Blanot

Centre national de la recherche scientifique

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Jean-Marie Pleau

Necker-Enfants Malades Hospital

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Geneviève Auger

Centre national de la recherche scientifique

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Mireille Dardenne

Centre national de la recherche scientifique

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Jean Martinez

École nationale supérieure de chimie de Montpellier

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Mireille Dardenne

Centre national de la recherche scientifique

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B.Ribadeau Dumas

Institut national de la recherche agronomique

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