Angiotensin-converting activity of tissue kallikrein.
This study examined the ability of tissue kallikreins, purified from both rat submandibular gland (SMG) and human urine, to form angiotensin II from synthetic angiotensin I. Both kallikreins converted angiotensin I to angiotensin II at neutral pH with the following kinetic constants: SMG kallikrein, Km = 9.43 x 10(-5) mol/l, Kcat = 1.58 mumols/mg protein/min; human urinary kallikrein, Km = 1.71 x 10(-4) mol/l, Kcat = 0.06 mumol/mg protein/min. These activities were not affected by angiotensin-converting enzyme (ACE) inhibitor. These results suggest that tissue kallikrein might participate in the formation of angiotensin II during administration of an ACE inhibitor.
Department of Internal Medicine, Fukuoka University School of Medicine, Japan.
M
M
Ideishi
M
M
Sasaguri
M
M
Ikeda
K
K
Arakawa
D000803:Angiotensin I / Q000378:metabolism*; D000804:Angiotensin II / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D007611:Aprotinin / Q000494:pharmacology; D002216:Captopril / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007610:Kallikreins / Q000378:metabolism*; D051381:Rats
D000804:Angiotensin II; D000803:Angiotensin I; D007611:Aprotinin; D002216:Captopril; D007610:Kallikreins