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H I Nakada

Publications and source records attributed to H I Nakada.

8 recordsLinked to original sources
PubMed1969

Structural analysis of colanic acid from Escherichia coli by using methylation and base-catalysed fragmentation. Comparison with polysaccharides from other bacterial sources.

Essentially the same methanolysis products were obtained after methylation of the slime and capsular polysaccharides from Escherichia coli K12 (S53 and S53C sub-strains) and the slime polysaccharides from E. coli K12 (S61), Aerobacter cloacae N.C.T.C. 5290 and Salmonella typhimurium SL1543. These were the methyl glycosides of 2-O-methyl-l-fucose, 2,3-di-O-methyl-l-fucose, 2,3-di-O-methyl-d-glucuronic acid methyl ester, 2,4,6-tri-O-methyl-d-glucose, 2,4,6-tri-O-methyl-d-galactose and the pyruvic acid ketal, 4,6-O-(1'-methoxycarbonylethylidene)-2,3-O-methyl-d-galactose. All were identified as crystalline derivatives from an E. coli polysaccharide. The structure of the ketal was proved by proton-magnetic-resonance and mass spectrometry, and by cleavage to pyruvic acid and 2,3-di-O-methyl-d-galactose. All these polysaccharides are therefore regarded as variants on the same fundamental structure for which the name colanic acid is adopted. Although containing the same sugar residues, quite different methanolysis products were obtained after methylation of the extracellular polysaccharide from Klebsiella aerogenes (1.2 strain). The hydroxypropyl ester of E. coli polysaccharide, when treated with base under anhydrous conditions, underwent beta-elimination at the uronate residues with release of a 4,6-O-(1'-alkoxycarbonylethylidene)-d-galactose. Together with the identification of 3-O-(d-glucopyranosyluronic acid)-d-galactose as a partial hydrolysis product, this establishes the nature of most, if not all, of the side chains as O-[4,6-O-(1'-carboxyethylidene)-d-galactopyranosyl]-(1-->4)-O-(d-glucopyranosyluronic acid)-(1-->3)-d-galactopyranosyl...

Chemical Phenomena↗
PubMed1964

Glucosamine-6-phosphate degradation by Proteus vulgaris and isolation of phosphoglucosaminisomerase.

Aron, H. (University of California, Santa Barbara), H. H. Yonenaka, and H. I. Nakada. Glucosamine-6-phosphate degradation by Proteus vulgaris and isolation of phosphoglucosaminisomerase. J. Bacteriol. 87:1123-1128. 1964.-The presence of the enzyme, phosphoglucosaminisomerase, was demonstrated in a strain of Proteus vulgaris. Fructose-6-phosphate and ammonia were shown to be the primary reaction products. The optimal pH was 7.2 with a broad peak. This differs from previously reported bacterial phosphoglucosaminisomerases which had a pH optimum of about 5.8. Other properties of the enzyme are presented.

Ammonia↗