5- Amino-4-imidazolecarboxamide

Imidazole-4-catbonitrile, 5-amino-synthesis, 5, 463 Imidazolecarboxamide, cyano-reactions, 5, 436 Imidazole-4-carboxamide Hofmann reaction, 5, 435 Imidazole-4-carboxamide, 5-amino-in histidine biosynthesis, 1, 90 reactions... 

This enzyme [EC 4.3.2.2], also referred to as adenylosuc-cinase, catalyzes the conversion of A -(l,2-dicarboxy-ethyl)AMP (or, adenylosuccinate) to yield fumarate and AMP. The enzyme will also convert l-(5-phosphoribo-syl)-4-(A-succinocarboxamide)-5-aminoimidazole to 5 -phosphoribosyl-5-amino-4-imidazolecarboxamide. 

Amino-4-imidazolecarboxamide was isolated from sulfonamide-inhibited cultures of Escherichia coli. - ° This substance also accumulates when Escherichia coli are inhibited by aminopterin, and is found in the culture medium of a purine-requiring mutant of Escherichia coZf. °... 

Amino-N-D-ribofuranosyl-4-imidazolecarboxamide (XXII) has been detected and isolated by several workers. It was isolated, as crystal-... 

Small quantities of the 5-amino-4-imidazolecarboxamide nucleotide were also isolated from the culture medium of Escherichia coli grown under sulfonamide bacteriostasis.i i This substance is considered to be an intermediate in purine biosynthesis, both in micro-organisms and in mammalian cells. In sulfonamide-inhibited cells and in the purine-requiring mutant of Escherichia coli, there is a block in the conversion of 5-amino-4-imidazole-carboxamide n-ribonucleotide to inosinic acid. The accumulated nucleotide in the bacterial cell is probably attacked by phosphatases this would explain why the nucleoside is the main metabolite. 

It has been shown that the accumulation of 5-amino-iV-D-ribosyl-4-imidazolecarboxamide in a purine-requiring mutant of Escherichia coli ceases when the bacteria are supplied with an excess of purine. The site of inhibition is, apparently, before the formation of the imidazole ring occurs, but after the formation of the D-ribosyl moiety, since adenine has only a... 

The 2-deoxy-D-ribosyl derivative of 5-amino-4-imidazolecarboxamide is claimed to have been detected when 5-amino-4-imidazolecarboxamide was incubated with a cell suspension of Escherichia coli B. 

It is reported that a purine-requiring mutant of Escherichia coli accumulated a substance related to 5-amino-iV-D-ribosyl-4-imidazolecarboxamide. Its ultraviolet absorption spectrum and its diazo chromogen spectrum differed from those of the known D-ribosyl derivative. Escherichia coli (strain B-96) converts it to 5-amino-4-imidazolecarboxamide, and it can be utilized by Escherichia coli B. It was suggested that it is an amino-(D-ribosyl)-imidazole. The accumulation of this substance was, however, somewhat surprising, since bacterial extracts of the purine-requiring mutant effected synthesis of 5-amino-4-imidazolecarboxamide from o-ribose 5-phosphate together with adenosine 5-triphosphoric acid and an energy source. 

Wl3. W3mgaarden, J. B., Seegmiller, J. E., Raster, L., and Blair, A. E., Utilization of hypoxanthine, adenine and 4-amino-5-imidazolecarboxamide for uric acid synthesis in man. Metab., Clin. ExpU. 8, 455-464 (1959). 

AICAR, 5-d mitio-1-(S-O-phosphono-0-i>-ribo-juranosyil-IH-imidazole-4-carboxamide S-amino-l-ribo-juranosylimidazoie-4-carboxamide S -phosphate 5-amino -4-imidazo]ecarboxamide ribonucleotide 5-amino -4-imid-azolecarboxamide ribotide 5-amino-I-<5 -phosphofurano-ribosyl)-4-imidazolecarboxamide. C,H SN40,P mol wt 338.22. C 31.96%, H 4.47%, N 16.57%. O 37.85%, P 9.16%. Synthesis from AIR Lukens, Buchanan, J. Am. Chem. Soc. 79, [511 (1957) J. Biol. Chem. 234, 1791 (1959). 

Figure 6 Amadori rearrangements catalyzed by HisA [A/-(5 -phospho-L-ribosyl-formimino)-5-amino-1 -(5 -phosphoribosyl)-4-imidazolecarboxamide isomerase] and TrpF (phosphoribosylanthranilate isomerase).

AMP, ADP, and ATP = adenosine mono-, di-, and triphosphate IMP = inosine 5 -monophosphate AICAR = 5 -phosphotibos5d-5-amino-4-imidazolecarboxamide DAP = diaminopimeUc acid PRPP = phosphoribosyl pyrophosphate a — KG A = a-ketoglutaric acid Orn = ornithine Cit = citruUine represents the one carbon unit lost to tetrahydrofolate as serine is converted to glycine. 

F2. Flaks, J. G., Erwin, M. J., and Buchaium, J. M., Biosynthesis of the purines— the synthesis of adenosine 5 phosphate and 5-amino-4-imidazolecarboxamide ribotide by a nucleotide pyrophosphorylase. J. Biol. Chem. 288, 201 (1957). 

It is of interest that many of the reduced folic derivatives prepared as a result of chemical studies of growth factors have subsequently been foimd to serve directly as coenzymes in the transfer of single carbon units. Reversible enzymatic transfer of the single carbon unit from anhydrofolinic acid to glycineamide ribotide, from Ai -formyltetrahydrofolic acid to 5-amino-4-imidazolecarboxamide ribotide, and from folinic acid to glutamic acid have been observed to be specific for these respective formyl donors -. ... 

The isolation of a diazotizable amine which accumulates in E. colt cultures grown in the presence of sulfonamides and its subsequent identification as 4-amino-5-imidazolecarboxamide (Fig. 3) has been... 

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