Progressive inhibition of human glandular (urinary) kallikrein by human serum and identification of the progressive antikallikrein as alpha 1-antitrypsin (alpha 1-protease inhibitor).
Human urinary kallikrein was inhibited by human alpha 1-antitrypsin (alpha 1-protease inhibitor) in a similar way as by equivalent amounts of human serum. The inhibitor present in the kallikrein-inhibitor complex formed was identified as alpha 1-antitrypsin by two-dimensional immunoelectrophoresis. Under the experimental conditions applied, 90 mIU (= 185 microgram) alpha 1-antitrypsin inhibits about 9 microgram of human urinary kallikrein in 24 h at 37 degrees C, 1 ml of human serum, containing 2-4 mg alpha 1-antitrypsin, inhibits about 70 microgram kallikrein. At an incubation temperature of 25 degrees C, the rate of inactivation is significantly lower than at 37 degrees C. No inhibition was observed at 0 degrees C or when alpha 1-antitrypsin was presaturated with trypsin.
D006801:Humans; D007122:Immunoelectrophoresis; D007610:Kallikreins / Q000037:antagonists & inhibitors* / Q000097:blood / Q000652:urine; D000515:alpha 1-Antitrypsin / Q000502:physiology*
D000515:alpha 1-Antitrypsin; D007610:Kallikreins