Reference

Impaired pteroylpolyglutamate synthesis in the cobalamin-inactivated rat

Impaired pteroylpolyglutamate synthesis in the cobalamin-inactivated rat. The effect of methionine, S-adenosylmethionine and 5'-methylthioadenosine in correcting the defect. Perry, Janet; Chanarin, I.; Deacon, Rosemary; Lumb, M. (Sect. Haematol., Northwick Park Hosp., Harrow/Middx., UK). Chem. Biol. Pteridines, Proc. Int. Symp. Pteridines Folic Acid Deriv.: Chem., Biol. Clin. Aspects, 7th, Meeting Date 1982, 807-13. Edited by: Blair, John A. de Gruyter: Berlin, Fed. Rep.Several substances with their cas registry numbers 6027-13-0 and 107-97-1 may be metioned in this study. Ger. (English) 1983. CODEN: 50NHAH. DOCUMENT TYPE: Conference CA Section: 1 (Pharmacology) Section cross-reference(s): 18 N2O breathing by rats resulted in impaired folate polyglutamate [32108-06-8] formation in the liver from i.p. administered H4PteGlu [135-16-0] in comparison with air-breathing rats. This impairment was overcome by the i.p. administration of formylfolates or L-methionine [63-68-3] and its derivs. Choline [62-49-7], betaine [107-43-7], and sarcosine [107-97-1] increased the amt. of polyglutamate formed in the N2O-breathing rat but were less effective than methionine. 5'-Methylthioadenosine [2457-80-9] was more effective than methionine in restoring the biosynthesis of folate polyglutamates in N2O-breathing rats when compared to that obsd. in controls. S-Adenosylmethionine [29908-03-0] was less effective than methionine but became equally effective when a larger amt. was given. Since breathing N2O leads to total inactivation of vitamin-B12 (cobalamin) [68-19-9] and to biochem. consequences which are similar to those seen in untreated pernicious anemia, these results are discussed with respect to the role of methylfolates in vitamin-B12 deficiency. .

Formation of L-methionine by methanol-utilizing bacteria

Formation of L-methionine by methanol-utilizing bacteria. Part V. Homocysteine transmethylation in methanol-utilizing bacteria and its application to L-methionine production. Morinaga, Yasushi; Tani, Yoshiki; Yamada, Hideaki (Res. Cent. Cell Tissue Cult., Kyoto Univ., Kyoto 606, Japan). Agric. Biol. Chem., 48(1), 143-8 (English) 1984. CODEN: ABCHA6. ISSN: 0002-1369. DOCUMENT TYPE: Journal CA Section: 16 (Fermentation and Bioindustrial Chemistry) Section cross-reference(s): 10 Resting cells of ribulose monophosphate pathway (RMP)-type methylotroph strain OM33 and serine pathway-type methylotroph Pseudomonas FM518 actively catalyzed the formation of L-methionine [63-68-3] from DL-homocysteine [454-29-5] and MeOH [67-56-1]. Cyanocobalamin [68-19-9] stimulated L-methionine formation by strain OM33, indicating that vitamin B12-dependent homocysteine transmethylase [9033-23-2] functions in this obligate methylotroph. 63-68-3 and 9033-23-2 are also in the experiment. L-Methionine formation by Pseudomonas FM518 was not stimulated by added cyanocobalamin because this strain is a vitamin B12-producer. Pseudomonas FM518 cells formed L-methionine with betaine [107-43-7] or L-serine [56-45-1] as well as MeOH the Me donor source. The conditions for the formation of L-methionine from DL-homocysteine and MeOH were investigated preliminarily using the reaction system with resting cells of an ethionine-resistant mutant of Pseudomonas FM518. The MeOH-grown cells at the exponential phase of growth possessed the highest activity. Under the optimum reaction conditions, 2.6 mM L-methionine was formed from 30 mM DL-homocysteine and 0.8M MeOH. .