title: On the biosynthesis of guanidinosuccinate.
abstract: We report a study motivated by a report that guanidinosuccinate is formed by transamidination from arginine to aspartate by perfused liver [J. Clin. Invest 57, 807 (1976)]. We prepared viable liver cells and incubated them with [14C]arginine labeled at the guanidino carbon and aspartate labeled at the methylene groups with tritium. A diacetyl-reacting band, similar to that reported with the perfusate in the above reference, was obtained by column chromatography. This band did not give a Sakaguchi reaction and contained no measurable tritium or 14C. Thus it did not derive from aspartate or arginine. On electrophoresis at pH 5.0, the diacetyl-reacting material moves to the cathode, guanidinosuccinate to the anode. The absorption spectrum of the diacetyl-reacting band showed a double peak, with maxima at 539 and 432 nm; guanidinosuccinate has only one maximum, at 533 nm. The diacetyl reagent reacts with sulfhydryl compounds and polypyrroles (e.g., bilirubin) to produce blue colors with significant absorbance in the 432-nm range. We saw no evidence for guanidinosuccinate formation by transamidination in these experiments with viable liver cells.
mesh_terms: D000818:Animals; D001120:Arginine / Q000378:metabolism; D001224:Aspartic Acid / Q000378:metabolism; D003124:Colorimetry; D006146:Guanidines / Q000096:biosynthesis*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D013053:Spectrophotometry; D013386:Succinates / Q000096:biosynthesis*
chemical_list: D006146:Guanidines; D013386:Succinates; D001224:Aspartic Acid; D001120:Arginine