Fluorometric determination of alpha-ketosuccinamic acid in rat tissues.
A method for the fluorometric determination of alpha-ketosuccinamic acid, the alpha-keto acid analog of asparagine, is described. The procedure involves the hydrolysis of alpha-ketosuccinamate to oxaloacetate by omega-amidase followed by NADH-dependent reduction of oxaloacetate to malate by malate dehydrogenase. A correction for endogenous oxaloacetate is made by using control samples lacking omega-amidase. Of the rat tissues investigated, liver contained the highest concentration, followed by kidney (53 +/- 6 (n = 11) and 18 +/- 3 (n = 3) mumol/kg wet wt, respectively). alpha-Ketosuccinamate was not detected in brain (less than 8 mumol/kg wet wt). Some chemical properties of alpha-ketosuccinamate were investigated. Concentrated solutions of sodium alpha-ketosuccinamate frozen for extended periods and the solid sodium salt of alpha-ketosuccinamate dimer heated to 130 degrees C are converted to at least 10 products by processes involving dimerization, dehydration, and decarboxylation. Isobutane chemical ionization mass spectral analysis (170-230 degrees C) of the free acid monomer yielded similar products. Many of the breakdown products were identified as di- and monoheterocyclic compounds, some of which are known to be of biological importance.
Department of Neurology, Cornell University Medical College, New York, New York 10021.
A J
AJ
Cooper
S P
SP
Raps
A
A
Meister
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D006571:Heterocyclic Compounds / Q000032:analysis; D008099:Liver / Q000032:analysis; D008297:Male; D010071:Oxaloacetates / Q000032:analysis*; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains; D013050:Spectrometry, Fluorescence
D006571:Heterocyclic Compounds; D010071:Oxaloacetates; C013183:2-oxosuccinamic acid