In vivo 13C and 15N NMR studies of methylamine metabolism in Pseudomonas species MA.
 

In vivo 13C and 15N NMR studies of methylamine metabolism in Pseudomonas species MA.

Related Articles In vivo 13C and 15N NMR studies of methylamine metabolism in Pseudomonas species MA.

J Biol Chem. 1991 Jun 25;266(18):11705-13

Authors: Jones JG, Bellion E

Pseudomonas species MA was grown with methylamine as a sole source of carbon and nitrogen enabling the total flow of carbon and nitrogen into this organism to be simultaneously monitored in vivo using 13C and 15N NMR. [13C]Methylamine was rapidly and extensively incorporated into the methyl group of N-methylglutamate during high oxygenation of the cell suspension, but when the oxygenation rate was lower, a significant portion was also found in the methyl group of gamma-glutamylmethylamide. At later times the carbon label was found in intermediates of the serine assimilation pathway, with glutamate derived from the tricarboxylic acid cycle being the most abundant product. Incorporation of [15N]methylamine was only detected as N-methyl[15N]glutamate, but when protein synthesis was inhibited, the label was also detected in the amino nitrogen of glutamate. When oxygenation rates were lower, the 15N-labeled methylamine was found in the methylamide group of gamma-glutamylmethylamide in addition to being incorporated into N-methylglutamate. gamma-Glutamylmethylamide formation was linked to the overall energy state of the cell and was not affected by inhibition of the carbon assimilation pathway. Neither 5-hydroxy-N-methylpyroglutamate nor N-methyl-alpha-ketoglutaramate were detected to any significant extent. A mechanism was proposed for the role of gamma-glutamylmethylamide in the regulation of endogenous nitrogen supplies in this organism.

PMID: 2050672 [PubMed - indexed for MEDLINE]



Source: PubMed