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R Y Stanier

Publications and source records attributed to R Y Stanier.

At least 19 recordsLinked to original sources
PubMed1978

Glucose-6-phosphate dehydrogenase of Anabaena sp. Kinetic and molecular properties.

The kinetic and molecular properties of cyanobacterial glucose-6-phosphate dehydrogenase, partly purified from Anabaena sp. ATCC 27893, show that it undergoes relatively slow, reversible transitions between different aggregation states which differ in catalytic activity. Sucrose gradient centrifugation and polyacrylamide gel electrophoresis reveal three pincipal forms, with approximate molecular weights of 120 000 (M1), 240 000 (M2) and 345 000 (M3). The relative catalytic activities are: M1 less than M2 less than M3. In concentrated solutions of the enzyme, the equilibrium favors the more active, oligomeric forms. Dilution in the absence of effectors shifts the equilibrium in favor of the M1 form, with a marked diminution of catalytic activity. This transition is prevented by a substrate, glucose-6-phosphate, and also by glutamine. The other substrate, nicotinamide adenine dinucleotide phosphate (NADP+), and (in crude cell-free extracts) ribulose-1,5-diphosphate are negative effectors, which tend to maintain the enzyme in the M1 form. The equilibrium state between different forms of the enzyme is also strongly dependent on hydrogen ion concentration. Although the optimal pH for catalytic activity is 7.4, dissociation to the hypoactive M1 form is favored at pH values above 7; a pH of 6.5 is optimal for maintenance of the enzyme in the active state. Reduced nicotamide adenine dinucleotide phosphate (NADPH) and adenosine 5'-triphosphate (ATP), inhibit catalytic activity, but do not significantly affect the equilibrium state. The relevance of these findings to the regulation of enzyme activity in vivo is discussed.

Adenosine Triphosphate↗
PubMed1971

Comparative immunology of algal biliproteins.

The three spectroscopically distinct classes of phycobiliproteins characteristic of the Cyanophyta and Rhodophyta-phycocyanins, allophycocyanins, and phycoerythrins-share no common antigenic determinants detectable by the Ouchterlony double diffusion technique. Each class of phycobiliprotein, from both Cyanophyta and Rhodophyta, possesses a strong determinant common to all members of that class. With respect to an antiserum directed against a specific cyanophytan biliprotein, all heterologous biliproteins of the same class are immunologically identical, as shown by the fact that absorption with a given heterologous antigen simultaneously eliminates crossreactions with other heterologous antigens. A cryptophytan phycoerythrin was found to be immunologically unrelated to any of the cyanophytan or rhodophytan biliproteins examined.

Cross Reactions↗
PubMed1971

Dissimilation of aromatic compounds by Alcaligenes eutrophus.

The range of aromatic compounds that support the growth of Alcaligenes eutrophus has been determined, and the pathways used for the dissimilation of these substrates have been explored, largely by enzymatic analyses. The beta-ketoadipate pathway operates in the dissimilation of benzoate and p-hydroxybenzoate; the genetisate pathway, in the dissimilation of m-hydroxybenzoate; and the meta cleavage pathway, in the dissimilation of phenol and p-cresol. l-Tryptophan is oxidized via anthranilate; but the metabolic fate of anthranilate was not established. The metabolism of the three stereoisomers of muconic acid was also examined.

Adipates↗
PubMed1971

Regulation of the -ketoadipate pathway in Alcaligenes eutrophus.

The regulation of the synthesis of the inducible enzymes that mediate the reactions of the beta-ketoadipate pathway in Alcaligenes eutrophus has been examined by determining the inductive responses of the wild type and of mutants derived from it to metabolites of the pathway. The system of control differs in many respects from those which operate in the genera Pseudomonas and Acinetobacter.

Adipates↗