title: Isolation and identification of urinary beta-aspartyl dipeptides and their concentrations in human urine.
abstract: beta-Aspartyl-methionine, -aspartic acid and -glutamic acid and gamma-glutamyl-threonine and -glycine were isolated and identified in human urine by ion-exchange chromatography, high-voltage paper electrophoresis, acid hydrolysis and determination of N-terminal amino acids of the isolated compounds, and comparison of their behaviors in paper electrophoresis and chromatography with those of the authentic compounds. The concentrations of acidic beta-aspartyl dipeptides in human urine were determined using an amino acid analyzer. Their concentrations were as follows: beta-aspartyl-glycine, male, 44.4 +/- 8.5, female, 61.4 +/- 18.9, child, 83.7 +/- 27.1; -alanine, male, 11.0 +/- 4.9, female, 20.7 +/- 12.0, child, 25.3 +/- 9.1; -glutamic acid, male, 10.0 +/- 3.7, female, 23.0 +/- 8.5, child, 20.4 +/- 7.5; -serine, male, 9.9 +/- 2.8, female, 13.6 +/- 3.8, child, 14.9 +/- 4.7; -aspartic acid, male, 4.3 +/- 1.0, female, 9.1 +/- 2.2, child, 18.4 +/- 6.5; -threonine, male 3.9 +/- 0.9, female, 5.8 +/- 1.1, child, 13.2 +/- 4.9 mumol/g creatinine (mean +/- S.D.). The order of the sum of their concentrations tended to be child greater than female greater than male. Patients receiving intravenous hyperalimentation also excreted acidic beta-aspartyl dipeptides into urine in amounts similar to those in females and in a pattern similar to that observed in healthy persons. This finding indicates that urinary beta-aspartyl dipeptides were probably of endogenous origin because oral nutrition was stringently excluded in these patients.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging; D001224:Aspartic Acid / Q000652:urine*; D002648:Child; D004151:Dipeptides / Q000302:isolation & purification / Q000652:urine*; D005260:Female; D005971:Glutamates / Q000652:urine; D005998:Glycine / Q000652:urine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008715:Methionine / Q000652:urine; D008875:Middle Aged; D009369:Neoplasms / Q000652:urine; D010289:Parenteral Nutrition, Total; D012737:Sex Factors; D013912:Threonine / Q000652:urine; D014511:Uremia / Q000652:urine
chemical_list: D004151:Dipeptides; D005971:Glutamates; D013912:Threonine; D001224:Aspartic Acid; D008715:Methionine; D005998:Glycine