Secretion of tyrosinase in Streptomyces glaucescens.

In Streptomyces glaucescens, the intracellular and the extracellular enzyme forms of tyrosinase were found to be indentical in molecular weight (29 000), in copper content (0.21%), in the 19 amino acids at the amino-terminal end and in the ratio of cresolase to catecholase activity (0,005). The tyrosinase secretion process exhibited a constant rate of 0.

A new rearrangement reaction in tyrosine metabolism.

Human faecal specimens were incubated under anaerobic conditions with several dideuterated tyrosine metabolites. 3-(4-Hydroxy[3,5-2H2]phenyl)propionic acid and 3-(4-hydroxy[3,5-2H2]phenyl)lactic acid yielded the rearrangment product 3-(3-hydroxy[2,4-2H2]phenyl)propionic acid. The starting materials as well as the product all contained two deuterium atoms both ortho to the hydroxyl group.

Glucose metabolism in Acetobacter aceti.

Acetobacter aceti NCIB 8554 grows on a minimal medium with ethanol but not with glucose as carbon and energy source. Addition of glucose to a wild type culture on ethanol has no influence on growth of the organism. Growth of a glucose sensitive mutant A5 is inhibited by the addition of glucose until all glucose has disappeared from the medium.

Characterization of the acetyl-CoA synthetase of Acetobacter aceti.

The acetate activating system of Acetobacter aceti has been studied. The enzyme responsible, acetyl-CoA synthetase, has been purified about 500-fold from crude cell extracts and was approximately 85% pure as judged by polyacrylamide gel electrophoresis in sodium dodecyl sulphate. The purified enzyme showed optimal activity at pH 7.

Study of the intestinal tyrosine metabolism using stable isotopes and gas chromatography-mass spectrometry.

Deuterated tyrosine, 4-hydroxyphenyllactic acid, 4-hydroxyphenylpropionic acid, 4-hydroxyphenylacetic acid and 4-hydroxybenzoic acid were incubated under anaerobic conditions with human faecal specimens for the in vitro study of their respective metabolisms. After 1 week, aromatic acids and phenols were extracted and analyzed by gas chromatography-mass spectrometry. [3',5'-2H2]Tyrosine produced 4-hydroxyphenyllactic acid, 4-hydroxyphenylpropionic acid and 4-hydroxyphenylacetic acid; [3',5'-2H2]-4'-hydroxyphenyllactic acid produced 4-hydroxyphenylpropionic acid, 3-hydroxyphenylpropionic acid, 4-hydroxyphenylacetic acid and phenylproionic acid; [3',5'-2H2]-4'-hydroxyphenyl-propionic acid produced 3-hydroxyphenylpropionic acid and phenylpropionic acid; [3',5',2,2-2H4]-4'-Hydroxyphenylacetic acid produced p-cresol; and [3',5'-2H2]-4'-hydroxybenzoic acid produced phenol.