Cell-free extracts of Pseudomonas M.A., a nonphotosynthetic bacterium which grows on methylamine as its sole source of carbon, nitrogen, and energy, have been shown to catalyze a reaction between methylamine and a-ketoglutaric acid. The product of this reaction has been identified as the cyclic amide, 5-hydroxy-N-methylpyroglutamic acid. This reaction is catalyzed by an enzyme which diEers from...

The activity of five liver enzymes involved in amino acid metabolism was found to be markedly increased in coldexposed rats. However, the activity of three of the enzymes, arginase, glutamic-oxalacetic and glutamic-pyruvic transaminase, was increased only as a result of a cold-induced higher protein intake. In contrast, the activity of tryptophan pyrrolase and tyrosine alpha ketoglutaric transm...

A method for isolating organic acids from acidified urine on an equivolume mixture of Porapak Q and Porapak T is described, and results are compared with extraction with ethyl acetate and ion exchange on DEAE-Sephadex. Average recoveries of 14C-labeled oxalic acid, lactic acid, succinic acid, alpha-ketoglutaric acid, citric acid, and cinnamic acid were equal to or better than those obtained wit...

Pyruvic and alpha-ketoglutaric acids were quantitatively and rapidly converted to quinoxalones by a new method, to enhance their detectability in the ultraviolet. The quinoxalones were separated by reversed-phase chromatography with use of 10 micronm particles packed in a 30-cm (length) column. An aqueous solution of ammonium acetate and methanol was used for linear gradient elution. The urinar...

The specific activities of isocitric dehydrogenase, alpha-ketoglutaric dehydrogenase, succinic dehydrogenase, malic dehydrogenase, and reduced nicotinamide adenine dinucleotide (NADH) oxidase were determined in extracts of Nitrosomonas europaea and compared with the corresponding values for Anacystis nidulans and autotrophically grown Hydrogenomonas eutropha. In common with other obligate autot...