Naoko Yamano

Expression of salmon growth hormone in the cyanobacteriumAgmenellum quadruplicatum

SummaryThe salmon growth hormone gene was introduced into the cyanobactriumAgmenellum quadruplicatum PR-6 by plasmid transformation. The gene expressed the hormone under thetrp promoter ofEscherichia. coli. The amount was estimated to be approximately 0.1% of the total cell protein.

Production of N-Acetylglucosamine Deacetylase by Vibrio cholerae Non-O1

Vibrio cholerae non-O1 (1148 A) produced β-N-acetylglucosamini-dase and N-acetylglucosamine (GlcNAc) deacetylase intracellularly when grown in chitin or GlcNAc containing medium. It also secreted chitinase only in the chitin-containing medium. The partially purified GlcNAc deacetylase deacetylated GlcNAc but not chitin oligosaccharides, the dimer to hexamer of GlcNAc. We also detected the reaction product by capillary electrophoresis.

Purification and Characterization of N-Acetylglucosamine-6-phosphate Deacetylase from a Psychrotrophic Marine Bacterium, Alteromonas Species.

Abstract: A psychrotrophic bacterium, strain Mct-9, which produced an N-acetylglucosamine-6-phosphate deacetylase, was isolated from a deep-seawater sample in the Mariana Trough. The Mct-9 strain was identified as Alteromonas sp. The native enzyme had a molecular mass of 164,000 Da, and was predicted to be composed of four identical subunits with molecular masses of 41,000 Da. The purified enzyme hydrolyzed N-acetylglucosamine (GlcNAc), GlcNAc-6-phosphate, and GlcNAc-6-sulfate. Considering the low Km and high kcat/Km for GlcNAc-6-phosphate, it probably acts as a GlcNAc-6-phosphate deacetylase in vivo. The enzyme was functional in the temperature range of 5° to 70°C and displayed optimal activity at 55°C. The optimal temperature was higher than that of the deacetylase from the mesophilic bacterium Vibrio cholerae non-O1. The characteristics of the GlcNAc-6-phosphate deacetylase from Alteromonas sp. are unique among psychrotrophs and psychrophiles, whose intracellular enzymes are mostly thermolabile.