 An improved technique for the preparation of Streptomyces peptidases and N-acetylmuramyl-l-alanine amidase active on bacterial wall peptidoglycansGhuysen, Jean-Marie  ; ; et alin Biochemistry (1969), 8(1), 213-222 Detailed reference viewed: 7 (1 ULg) Structure des parois de Bacillus megaterium KM II. étude des complexes mucopeptidique et phosphomucopolysaccharidiqueGhuysen, Jean-Marie ; ; in Biochimica et Biophysica Acta (1962), 63 Bacillus megaterium KM cell walls are composed of two distinct heteropolymers. The first, referred as to X-teichoic acid, presents a molecular weight of about 11000. It consists of about 10 subunits ... [more ▼] Bacillus megaterium KM cell walls are composed of two distinct heteropolymers. The first, referred as to X-teichoic acid, presents a molecular weight of about 11000. It consists of about 10 subunits containing P, glucose and GlcNHAc in the molar ratio 1/2/1.3 as well as a polyol compound. It does not play any role in maintaining the rigidity of the wall. The second can be visualized as a three-dimensional network of structural subunits consisting of four mucopeptide residues with an average composition GlcNHAc1- (N-acetylmuramic acid)1-Ala2.20-Glu1- ([alpha],[epsilon]-diaminopimelic acid)1. They also contain glucose. This mucopeptide is the basal structure of the wall. The two heteropolymers are present in equimolar proportions. They are covalently bound through glucosido-muraminyl bridges branched on some of the alanine residues of the basal mucopeptide thanks to amidic linkages. [less ▲] Detailed reference viewed: 19 (0 ULg)Purification de la [beta]-(1-4)-N-acétylhexosaminidase sécrétée par Streptomyces albus G et active sur les parois de Micrococus lysodeikticus; Ghuysen, Jean-Marie in Biochimica et Biophysica Acta (1962), 58 The N-acetylhexosaminidase (referred as Str) secreted by Streptomyces albus G. has been purified by zone electrophoresis. It is slightly less basic than egg-white lysozyme. Its isoelectric point is close ... [more ▼] The N-acetylhexosaminidase (referred as Str) secreted by Streptomyces albus G. has been purified by zone electrophoresis. It is slightly less basic than egg-white lysozyme. Its isoelectric point is close to pH 10.3. It has no action on the [alpha]- and [beta]-phenylglycosides of N-acetylglucosamine and on the disaccharides [beta]-(1-4)-di-N-acetylglucosamine (di-N-acetylchitobiose) and [beta]-(1-6)-N-acetylglucosaminyl-N-acetylmuramic acid but it splits the tetrasaccharide [beta]-(1-4)-tetra-N-acetylglucosamine(tetra-N-acetylchitotetraose) in di-N-acetylchitobiose. Contrary to lysozyme, it does not split the tetrasaccharide O-[beta]-N-acetylglucosaminyl-(1-6)-O-[beta]-N-acetylmuraminyl-(1-4)-O-[beta]-N-acetylglucosaminyl-(1-6)-[beta]-N-acetylmuramic acid in disaccharide by hydrolyzing the [beta](1-4) linkage. In those conditions the disaccharide liberated, as well as the tetrasaccharide, from Microccus lysodeikticus cell walls after incubation with the N-acetylhexosaminidase Str, can not be put down to a further digestion of some tetrasaccharidic fragments. A chitobiase only active on the [beta]-phenyl-glycoside of N-acetylglucosamine and on the di-N-acetylchitobiose is also present in contentrated culture filtrates. It is a protein acid at pH 6.6. [less ▲] Detailed reference viewed: 15 (0 ULg)Structure des parois de Bacillus megaterium KM I. Isolement de l'amidase et d'un enzyme nouveau sécrétés par Streptomyces albus G et actifs sur les parois de Bacillus megaterium KM et de Micrococcus lysodeikticusGhuysen, Jean-Marie ; ; in Biochimica et Biophysica Acta (1962), 63(2), 286-296 The Streptomyces albus G enzymic complex of the F2B preparation has been fractionated by zone electrophoresis in sucrose gradient. Five enzymes have been shown to be present and three of them have been ... [more ▼] The Streptomyces albus G enzymic complex of the F2B preparation has been fractionated by zone electrophoresis in sucrose gradient. Five enzymes have been shown to be present and three of them have been fully separated. Three distinct enzymes make the casein no further precipitable by the trichloroacetic acid. They are likely not to have any action on Bacillus megaterium KM and on Micrococcus lysodeikticus cell walls. A fourth enzyme is the amidase previously studied which splits the muraminyl-alanine linkages present in the bacterial walls. The amidase does not clarify by itself the wall suspensions so far examined but enhances the lytic activity of a fifth enzyme also present in the F2B preparation. As lysozyme and Streptomyces N-acetylhexosaminidase, this fifth enzyme seems to act at the level of the polysaccharide residues of the walls basal mucopeptide but, contrary to those enzymes, its hydrolyzing action does not induce the liberation of free oligosaccharides from Micrococcus lysodeikticus walls. This enzyme will be referred to as Enzyme “32”. [less ▲] Detailed reference viewed: 40 (0 ULg)Le carbamate de propynylcyclohexanol étude pharmacologique et biologique; ; et al in Archives Internationales de Pharmacodynamie et de Thérapie (1959), 119(1-2), 264-274 Propnylcyclohexanol carbamate (L.2103) has more intense hypnotic and sedative properties, and a better therapeutic index than the carbamates of homologous propargylic cycloaliphatic carbinols. The synergy ... [more ▼] Propnylcyclohexanol carbamate (L.2103) has more intense hypnotic and sedative properties, and a better therapeutic index than the carbamates of homologous propargylic cycloaliphatic carbinols. The synergy between L.2103 and chlorpromazine, barbiturates, and the promethazine-pethidine association is demonstrated, as well as the antagonism of L.2103 in regard to some convulsant drugs acting at various levels of the central nervous system. Although having sedative properties, L.2103 administered by oral and parental routes to the dog, has been studied. The percentage of reducing metabolites found in the urines is small and persists longer than hypnotic activity. The nature of these metabolites is discussed. [less ▲] Detailed reference viewed: 8 (1 ULg) |
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