ABSTRACT
A new oxidative reaction of ethylene glycol was found with two alcohol oxidases from methanol yeast, Candida sp. and Pichia pastoris. Both alcohol oxidases oxidized ethylene glycol to glyoxal via glycolaldehyde. The optimum pHs for the oxidation of ethylene glycol and glycolaldehyde by the Candida alcohol oxidase were around 8.5 and 5.5, respectively, and their apparent Kms were 2.96 m and 28.6 mm, respectively. The optimum temperature was 40°C at pH 7.0. The optimum pHs for the oxidation of ethylene glycol and glycolaldehyde by the Pichia alcohol oxidase were around 8.0 and 6.0, respectively, and their optimum temperatures were 50 and 45°C, respectively, at pH 7.0. The apparent Km for glycolaldehyde was found to be 83.3 mm. For the accumulation of glyoxal, addition of catalase was effective, and a higher amount of glyoxal was obtained at a much lower temperature than the optimum for the alcohol oxidase. When 0.1 m ethylene glycol and glycolaldehyde were incubated with 80 units of the Pichia enzyme at 10°C, both substrates were almost completely converted to glyoxal after 10 and 3h of incubation, respectively.
ABSTRACT
The nucleotide sequence of a BglII fragment (3188 bp) from the plasmid pKY1 of Rhodospirillum rubrum was determined. A significant similarity was found between the amino acid sequences deduced from the nucleotide sequence of BglII fragment with that of algA, encoding the bifunctional enzyme with both the activities of phosphomannose isomerase and guanosine diphospho-D-mannose pyrophosphorylase of Pseudomonas aeruginosa.
Subject(s)
Bacterial Proteins , Mannose-6-Phosphate Isomerase/genetics , Multienzyme Complexes/genetics , Nucleotidyltransferases/genetics , Rhodospirillum/genetics , Amino Acid Sequence , Base Sequence , Molecular Sequence Data , Open Reading Frames , Plasmids , Pseudomonas aeruginosa/genetics , Sequence Homology, Amino AcidABSTRACT
An enzyme which reduces glycolate to glycolaldehyde as the first step of the biosynthesis of vitamin B6 was studied using the particulate fraction of Flavobacterium sp. 238-7, a vitamin B6 producer. The enzyme catalyzes the reduction of glycolate in the presence of NADPH, but not the oxidation of glycolaldehyde, and is designated as glycolate reductase. There is a positive correlation between the activity of the enzyme and vitamin B6 biosynthesis. The activity and the formation of the enzyme were not affected by vitamin B6. This enzyme probably plays a role in the extraordinary accumulation of vitamin B6 by the bacterium.