A Method for the Determination of Formiminoglutamic Acid in Urine1

Tabor, Herbert; Wyngarden, Lillian J.

doi:10.1172/jci103670

Cited by 186 publications

(52 citation statements)

References 22 publications

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“…Perhaps the extramitochondrial pool expands because of interference with mitochondrial one-carbon metabolism and then drives compensating fluxes through non-mitochondrial reactions. Although 10-CHO-THF and 5,10-CHϭTHF could not be distinguished analytically, it seems probable that 10-CHO-THF predominates in vivo because the chemical equilibrium between the two forms lies strongly (ϳ95%) toward 10-CHO-THF at physiological pH (30).…”

Section: -Formyltetrahydrofolate In Arabidopsismentioning

confidence: 94%

“…These procedures do not distinguish between 10-CHO-THF and 5,10-CHϭTHF, which are interconverted during sample processing and finally both measured as 5,10-CHϭTHF (27). (Efforts were made to preserve 5,10-CHϭTHF by extraction in maleate buffer (30) and to estimate it as an increase in 5-CH 3 -THF following NaBH 4 reduction (31), but this maneuver gave poor results with plant samples.) Other HPLC-based procedures likewise fail to distinguish 10-CHO-THF from 5,10-CHϭTHF, measuring both as 10-CHO-THF (30).…”

Section: -Formyltetrahydrofolate In Arabidopsismentioning

confidence: 99%

“…(Efforts were made to preserve 5,10-CHϭTHF by extraction in maleate buffer (30) and to estimate it as an increase in 5-CH 3 -THF following NaBH 4 reduction (31), but this maneuver gave poor results with plant samples.) Other HPLC-based procedures likewise fail to distinguish 10-CHO-THF from 5,10-CHϭTHF, measuring both as 10-CHO-THF (30). It is thus currently not feasible to determine the individual amounts of 10-CHO-THF and 5,10-CHϭTHF present in vivo, but only their sum (henceforth termed 10-CHO-/5,10-CHϭTHF).…”

Section: -Formyltetrahydrofolate In Arabidopsismentioning

confidence: 99%

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5-Formyltetrahydrofolate Is an Inhibitory but Well Tolerated Metabolite in Arabidopsis Leaves

Goyer

Collakova

Garza

et al. 2005

Journal of Biological Chemistry

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5-Formyltetrahydrofolate (5-CHO-THF) is formed viaa second catalytic activity of serine hydroxymethyltransferase (SHMT) and strongly inhibits SHMT and other folate-dependent enzymes in vitro. The only enzyme known to metabolize 5-CHO-THF is 5-CHO-THF cycloligase (5-FCL), which catalyzes its conversion to 5,10-methenyltetrahydrofolate. Because 5-FCL is mitochondrial in plants and mitochondrial SHMT is central to photorespiration, we examined the impact of an insertional mutation in the Arabidopsis 5-FCL gene (At5g13050) under photorespiratory (30 and 370 mol of CO 2 mol ؊1 ) and non-photorespiratory (3200 mol of CO 2 mol ؊1 ) conditions. The mutation had only mild visible effects at 370 mol of CO 2 mol ؊1 , reducing growth rate by ϳ20% and delaying flowering by 1 week. However, the mutation doubled leaf 5-CHO-THF level under all conditions and, under photorespiratory conditions, quadrupled the pool of 10-formyl-/5,10-methenyltetrahydrofolates (which could not be distinguished analytically). At 370 mol of CO 2 mol ؊1 , the mitochondrial 5-CHO-THF pool was 8-fold larger in the mutant and contained most of the 5-CHO-THF in the leaf. In contrast, the buildup of 10-formyl-/5,10-methenyltetrahydrofolates was extramitochondrial. In photorespiratory conditions, leaf glycine levels were up to 46-fold higher in the mutant than in the wild type. Furthermore, when leaves were supplied with 5-CHO-THF, glycine accumulated in both wild type and mutant. These data establish that 5-CHO-THF can inhibit SHMT in vivo and thereby influence glycine pool size. However, the near-normal growth of the mutant shows that even exceptionally high 5-CHO-THF levels do not much affect fluxes through SHMT or any other folate-dependent reaction, i.e. that 5-CHO-THF is well tolerated in plants. 5-Formyltetrahydrofolate (5-CHO-THF)1 is formed from 5,10-methenyltetrahydrofolate (5,10-CHϭTHF) by a hydrolytic reaction catalyzed by serine hydroxymethyltransferase (SHMT) in the presence of glycine (1, 2). Spontaneous chemical hydrolysis of 5,10-CHϭTHF may be a minor additional source (3). 5-CHO-THF is the most stable natural folate and the most enigmatic, for it is the only one that does not serve as a cofactor in one-carbon metabolism. Instead, 5-CHO-THF is a potent inhibitor of SHMT and most other folate-dependent enzymes in vitro (4, 5). 5-CHO-THF probably acts as a stable storage form of folate in seeds and fungal spores (5-7), but it is not clear what role, if any, it plays in metabolically active tissues (8). This question is particularly pertinent for leaves. Leaf mitochondria have very high levels of SHMT and, during photorespiration, receive a massive influx of glycine (which leads to a matching SHMT-mediated glycine 3 serine flux) (9). Conditions in leaf mitochondria therefore favor 5-CHO-THF formation (Fig. 1). Indeed, 5-CHO-THF can comprise 50% of the folate pool in leaf mitochondria (10, 11), which is far more than in mammalian mitochondria (12)(13)(14). Furthermore, 5-CHO-THF is reported to make up 14 -40% of the folate pool in leaves and o...

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Section: -Formyltetrahydrofolate In Arabidopsismentioning

confidence: 94%

Section: -Formyltetrahydrofolate In Arabidopsismentioning

confidence: 99%

Section: -Formyltetrahydrofolate In Arabidopsismentioning

confidence: 99%

See 1 more Smart Citation

5-Formyltetrahydrofolate Is an Inhibitory but Well Tolerated Metabolite in Arabidopsis Leaves

Goyer

Collakova

Garza

et al. 2005

Journal of Biological Chemistry

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“…The autoclaved samples were prepared as follows. To 1 ml of urine, 1 drop of 1.0 M potassium hydroxide was added and the urine autoclaved at 15 (19) but leaves the UA intact.…”

Section: Methodsmentioning

confidence: 99%

Urinary Urocanic Acid in Man: The Identification of Urocanic Acid and the Comparative Excretions of Urocanic Acid and N-Formiminoglutamic Acid After Oral Histidine in Patients With Liver Disease

Merritt¹,

Rucknagel²,

Silverman³

et al. 1962

J. Clin. Invest.

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“…Bermett and Chanarin (1961) reported finding urocanic acid and Figlu in the mine of patients with Addisonian Pernicious Anaemia, postgastrectomy megaloblastic anaemia, idiopathic steatorrhoea, iron-deficient anaemia, haemolytic anaemia, carcinomatosis and acute leukaemia. Various methods have been described for the estimation of Figlu (Tabor and Wyngarden, 1958;Davis and Onesti, 1960;Knowles, Prankerd and Westall, 1960) but these methods are insensitive to urocanic acid. Two methods are available for estimating both urocanic acid and Figlu (Silverman, Gardiner and Condit, 1958;Chanarin and Bennett, 1962).…”

Section: Introductionmentioning

confidence: 99%

Urocanic and Formiminoglutamic Acid Excretion

Kelly

1963

Aust J Exp Biol Med

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SUMMARY.The normal range for the urinary excretion of histidine metabolites after an oral loading dose of 15 grams of histidine monohydrochloride was 0-22-3 mg./5 hour urine. The excretion rates of the individual metabolites were formiminoglutamic acid 0-16'6 mg./5 hour urine and urocanic acid 0-9-6 mg./5 hour urine. No significant difference was found between the levels in males and females.The urines of 31 patients were examined for histidine metabolites after oral loading with 15 grams of histidine monohydrochloride. Twenty-one patients excreted abnormal quantities of Figlu, and eight also excreted an excess of urocanic acid. Urocanic acid may make a significant contribution to the total histidine metabolites excreted.INTRODUCTION.

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A Method for the Determination of Formiminoglutamic Acid in Urine1

Cited by 186 publications

References 22 publications

5-Formyltetrahydrofolate Is an Inhibitory but Well Tolerated Metabolite in Arabidopsis Leaves

5-Formyltetrahydrofolate Is an Inhibitory but Well Tolerated Metabolite in Arabidopsis Leaves

Urinary Urocanic Acid in Man: The Identification of Urocanic Acid and the Comparative Excretions of Urocanic Acid and N-Formiminoglutamic Acid After Oral Histidine in Patients With Liver Disease

Urocanic and Formiminoglutamic Acid Excretion

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