The vasoactive proteins in human urine

We have purified vasoactive polypeptides from the urine of normotensive humans by gel filtration on Sephadex G150 superfine ionic exchange chromatography on DEAE-cellulose and isoelectric focusing in polyacrylamide gels using a pharmalyte pH range of 2.5-5.0. The purified polypeptide fraction yielded four bands by isoelectric focusing with isoelectric points at pH 4.15, 4.05, 3.9 and 3.8. On dodecyl sulphate/polyacrylamide gel electrophoresis (page) two bands appeared, one small band with a Mr of 29 000 and one broad band ranging from Mr 49 000 to Mr 42 500. The polypeptides lower the blood pressure of rabbits in a bioassay and cleave D-valyl-L-leucyl-L-arginine-4-nitroanilide with a specific activity comparable to that of kallikrein.