title: Spectrometric determination of urokinase in urine after gel filtration, using the chromogenic substrate S-2444.
abstract: Using the chromogenic substrate S-2444, the spectrometric determination of urokinase (EC 3.4.21.31) in urine subjected to gel filtration was evaluated. Pure urokinase solutions were used to standardize analytical conditions. A low molecular mass (relative molecular mass < 5000) heat resistant (60 min, 97 degrees C) activity could be removed from urine by gel filtration (Sephadex G 25 Medium). In the analysis of the high molecular mass fraction (relative molecular mass > 5000) of urine, amidolysis remained linear during a period of 3 hours. The relation between enzyme activity and substrate turnover was linear in the range from 0.05-12 U/l. The coefficients of variation for within-run precision ranged from 1.4-3.8%. The analytical recovery was 98-104%. Average urokinase excretion in morning urines (collection period 1-3 hours) of 10 healthy males and 10 healthy females was respectively 0.82 and 0.68 U/g creatinine.
mesh_terms: D002850:Chromatography, Gel; D002863:Chromogenic Compounds; D003404:Creatinine / Q000652:urine; D010450:Endopeptidases / Q000652:urine*; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D009842:Oligopeptides; D012016:Reference Values; D013053:Spectrophotometry / Q000379:methods; D014568:Urokinase-Type Plasminogen Activator / Q000302:isolation & purification / Q000652:urine*
chemical_list: D002863:Chromogenic Compounds; D009842:Oligopeptides; D003404:Creatinine; D010450:Endopeptidases; D014568:Urokinase-Type Plasminogen Activator