Abstract
Enzymic formation of dimethylamine and formaldehyde from trimethylamine oxide by an extract of the acetone powder prepared from the pyloric caeca of Theragra chalcogramma was examined under various conditions, and a method was established for the assay of the enzyme activity., That is, under anaerobic condition in Thunberg tube, a mixture of 0.5ml of 0.1M trimethylamine oxide, 1.0ml of 0.1mM methylene blue, and 0.5ml of chicken liver extract was incubated with an aliquot of the crude enzyme at 30°C, pH 5.0, and the dimethylamine or formaldehyde formed during the incubation period was measured.
Some properties of the enzymic reaction were also investigated. Results obtained were as follows:
1) The optimum pH of the enzyme reaction was 5.0, but the enzyme was most stable at pH 6.2 on heating.
2) The enzyme was labile on heating at temperatures higher than 40°C.
3) As for the substances examined, the enzymic reaction was specific for tertiary amine N-oxide.
4) The enzymic reaction was stimulated by Fe2+, L-Ascorbic acid, FMN, or betaine, and inhibited by Fe3+, Cu2+, EDTA, trimethylamine, or choline.
