Salmonella typhimurium methylated

The lipopolysaccharides have been isolated from two wild-type strains of E. coli K12, two core-deficient mutants, and an SR recombinant with Salmonella typhimurium Methylation analysis of the oligosaccharides released on dephosphorylation of the lipopolysaccharides revealed differences in the extents of completion of the core structures. The non-reducing end of the complete core structure of lipopolysaccharides from the E. coli K12 wild-type strains is substituted with either 2-acetamido-2-deoxy-D-glucose or, possibly, 2-acetamido-2-deoxy-D-mannopyranosyluronic acid, whereas the complete K12 core in the SR recombinant is substituted with an S-specific oligosaccharide of S. typhimurium. These substituents are attached to 0-6 of the D-glucopyranosyl residue at the non-reducing end of the core oligosaccharide, as shown in (8). 

When methyl parathion was tested in Salmonella typhimurium, eontradictory results were reported with or without using metabolie aetivation (Rashid and Mumma 1984 Shigaeva and Savitskaya 1981 Waters... 

Using PTLC six major fractions of lipids (phospholipids, free sterols, free fatty acids, triacylglycerols, methyl esters, and sterol esters) were separated from the skin lipids of chicken to smdy the penetration responses of Schistosoma cercaria and Austrobilharzia variglandis [79a]. To determine the structure of nontoxic lipids in lipopolysaccharides of Salmonella typhimurium, monophosphoryl lipids were separated from these lipids using PTLC. The separated fractions were used in FAB-MS to determine [3-hydroxymyristic acid, lauric acid, and 3-hydroxymyristic acids [79b]. 

Desmutagenic activity. Fresh plant juice, on agar plate at a concentration of 0.5 mL/ disc, was inactive on Salmonella typhimurium TA98 L Homogenate of the fresh root, at a concentration of 100 pL/disc on agar plate, was active on Salmonella typhimurium TA98 and TAIOO vs l,4-dinitro-2-methyl pyrrole mutagenesis ". 

Methyl bromide induced SOS repair in Salmonella typhimurium and gene mutation... 

Penman, B.W., Hoppe, H.T. Thilly, W.G. (1979) Concentration-dependent mutation by alkylating agents in human lymphoblasts and Salmonella typhimurium. V-methyl-V-nitrosoure-thane and P-propiolactone. J. natl Cancer Inst., 63, 903-907... 

K. El-Bayoumy et al., The effects of bay-region methyl substitution on 6-nitrochrysene mutagenicity in Salmonella typhimurium and tumorigenicity in newborn mice. Carcinogenesis 10, 1685-1689 (1989)... 

A methylesterase which catalyzes the hydrolysis of y-glu-tamyl methyl esters of membrane bound proteins in Salmonella typhimurium and JJ. coli has recently been identified (25). Apparently, these membrane-bound proteins undergo methylation by a S-adenosylmethionine requiring methyltransferase (similar to transferase II). In this case the methylation and demethylation are directly associated with the chemotactic mobility of the microorganisms. When the cells are exposed to a chemotactic attractant, methylation of the membrane-bound proteins increases and straight-line movement up the gradient is induced. When the attractant is removed or a repellent substituted, the esterase decreases the methylation and random movement results. These control mechanisms are analogous in regulation to some of the reversible processes such as adenylation (26), uridylation (27) and phosphorylation (28). 

Andre, V, Boissart, C, Sichel, F., Gauduchon, R, Le, T.J., Lancelot, J.C., Mercier, C., Chemtob, S., Raoult, E. and Tallec, A. (1997). Mutagenicity of Nitro- and Amino-Substituted Carbazoles in Salmonella typhimurium. III. Methylated Derivatives of 9H-carbazole. MutRes., 389, 2A1-260. 

McGregor DB, Cruzan G, Callander RD, May K, Banton M (2005) The mutagenicity testing of tertiary-butyl alcohol, tertiary-butyl acetate, and methyl tertiary-butyl ether in Salmonella typhimurium. Mutat Res 565 181-189... 

Since the discovery in 1959 of a methylated lysine derivative in flagella protein of Salmonella typhimurium (181), many methylated amino acid derivatives have been found in a large number of proteins (Table VII). Three excellent recent reviews are available on this subject (182,183,184). 

Cooper, M.T. and T.D. Porter (2001). Cytochrome b(5) coexpression increases the CYP2E1-dependent mutagenicity of dialkylnitrosamines in methyl-transferase-deficient strains of Salmonella typhimurium. Mutat. Res. 484, 61-68. 

Eisenstark et al. (15A11), nearly a decade before Ames 1973 presentation on the use of Salmonella typhimurium to test for mutagenicity, described the high mutagenicity obtained with NNAs in tests with Salmonella typhimurium. Several potent NNAs became positive standards, e.g., A-methyl-A -nitro-A-nitrosoguanidine in the Ames test with Salmonella typhimurium. 

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