Biomaterial Database

Kininase II of human seminal fluid: kinetics and inhibition. 1986

M van Sande, and H Neels, and S Scharpé, and B Holmquist

The activity of kininase II in crude human sperm was measured continuously by measuring the hydrolysis of a blocked tripeptide 3-(2-furylacryloyl)-L- phenylalanyl-glycyl-glycine (1 mmol/l). Mean seminal plasma activity was 335 +/- 61 U/g protein; the Km was 0.7 mmol/l; pH optimum was 8.8 in a 50 mmol/l HEPES buffer and the chloride optimum was 300 mmol/l. This male genital tract enzyme is inhibited by several kininase II inhibitors. Captopril (SQ 14225) showed IC50 = 1.6 X 10(-8) mol/l, with a competitive pattern (Ki = 7.3 X 10(-9)). 3-(Mercaptomethyl)-oxo-piperidineacetic acid showed the same kind of inhibition with an IC50 = 1.8 X 10(-6) mol/l (Ki = 6.8 X 10(-7) mol/l). Enalapril diacid was the most potent inhibitor and had an IC50 of 4.1 X 10(-9) mol/l and showed a mixed competitive and non-competitive inhibition (Ki = 10(-9) mol/Ki' = 9.5 X 10(-10) mol/l). These in vitro inhibition data suggest that, in vivo, such drugs may effect the function of kininase II in the male reproductive system. The observed 50% inhibition constants are comparable to those observed in lung enzyme suggesting similar kinetic properties.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007703	Peptidyl-Dipeptidase A	A peptidyl-dipeptidase that catalyzes the release of a C-terminal dipeptide, oligopeptide-\|-Xaa-Yaa, when Xaa is not Pro, and Yaa is neither Asp nor Glu. Thus, conversion of ANGIOTENSIN I to ANGIOTENSIN II, with increase in vasoconstrictor activity, but no action on angiotensin II. It is also able to inactivate BRADYKININ, a potent vasodilator; and has a glycosidase activity which releases GPI-anchored proteins from the membrane by cleaving the mannose linkage in the GPI moiety. (From https://www.uniprot.org April 15, 2020).	ACE1 Angiotensin-Converting Enzyme 1,ACE1 Protein,Angiotensin Converting Enzyme,Angiotensin Converting Enzyme 1,Antigens, CD143,CD143 Antigens,Dipeptidyl Carboxypeptidase I,Kininase II,Peptidase P,Angiotensin I-Converting Enzyme,Carboxycathepsin,Dipeptidyl Peptidase A,Kininase A,ACE1 Angiotensin Converting Enzyme 1,Angiotensin I Converting Enzyme,Carboxypeptidase I, Dipeptidyl,Peptidyl Dipeptidase A
D008297	Male		Males
D010880	Piperidines	A family of hexahydropyridines.
D010881	Piperidones	A family of saturated heterocyclic organic compounds which contain one nitrogen atom and a carbonyl group in the ring structure.	Piperidone
D002216	Captopril	A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.	(S)-1-(3-Mercapto-2-methyl-1-oxopropyl)-L-proline,Capoten,Lopirin,SQ-14,225,SQ-14,534,SQ-14225,SQ-14534,SQ 14,225,SQ 14,534,SQ 14225,SQ 14534,SQ14,225,SQ14,534,SQ14225,SQ14534
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D004656	Enalapril	An angiotensin-converting enzyme inhibitor that is used to treat HYPERTENSION and HEART FAILURE.	Enalapril Maleate,MK-421,MK421,Renitec,Renitek,MK 421,Maleate, Enalapril
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000806	Angiotensin-Converting Enzyme Inhibitors	A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility.	ACE Inhibitor,ACE Inhibitors,Angiotensin Converting Enzyme Inhibitor,Angiotensin I-Converting Enzyme Inhibitor,Angiotensin-Converting Enzyme Inhibitor,Kininase II Inhibitor,Kininase II Inhibitors,Angiotensin I-Converting Enzyme Inhibitors,Angiotensin-Converting Enzyme Antagonists,Antagonists, Angiotensin-Converting Enzyme,Antagonists, Kininase II,Inhibitors, ACE,Inhibitors, Angiotensin-Converting Enzyme,Inhibitors, Kininase II,Kininase II Antagonists,Angiotensin Converting Enzyme Antagonists,Angiotensin Converting Enzyme Inhibitors,Angiotensin I Converting Enzyme Inhibitor,Angiotensin I Converting Enzyme Inhibitors,Antagonists, Angiotensin Converting Enzyme,Enzyme Antagonists, Angiotensin-Converting,Enzyme Inhibitor, Angiotensin-Converting,Enzyme Inhibitors, Angiotensin-Converting,II Inhibitor, Kininase,Inhibitor, ACE,Inhibitor, Angiotensin-Converting Enzyme,Inhibitor, Kininase II,Inhibitors, Angiotensin Converting Enzyme