title: Angiotensin-producing enzyme I of serum: formation by immunization with renin.
abstract: Immunization with renin from the kidneys of hog, beef, dog, rabbit and man induced the formation of a highly active enzyme (enzyme I) in the serum of dogs, guinea pigs, rabbits and rats. Enzyme I produces angiotensin I maximally at pH 4.7, up to 2900 ng/ml serum/h, i.e. at a rate 2500 times higher than the endogenous renin of normal serum. At pH 7.2 the angiotensin I production by enzyme I is about 16 to 28 times higher than that of plasma renin. Enzyme I is produced by immunization with renin and not by other kidney proteins. Enzymatically-active renin is required and separate mechanisms are involved in the formation of enzyme I and antirenin. Enzyme I is not identical to renin, pepsin, cathepsin D, plasmin, tonin or cathepsin G and it is inhibited by pepstatin, but not by diisopropyl fluorophosphate.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000502:physiology; D002268:Carboxypeptidases / Q000096:biosynthesis*; D002402:Cathepsin D / Q000037:antagonists & inhibitors / Q000378:metabolism; D056649:Cathepsin G; D002403:Cathepsins / Q000378:metabolism; D002417:Cattle; D004285:Dogs; D005341:Fibrinolysin / Q000378:metabolism; D006168:Guinea Pigs; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007114:Immunization; D001121:Lysine Carboxypeptidase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000097:blood; D010434:Pepsin A / Q000037:antagonists & inhibitors / Q000378:metabolism; D010436:Pepstatins / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D012083:Renin / Q000276:immunology* / Q000378:metabolism; D012697:Serine Endopeptidases; D013379:Substrate Specificity; D013552:Swine
chemical_list: D000906:Antibodies; D010436:Pepstatins; C014195:Streptomyces pepsin inhibitor; D002268:Carboxypeptidases; D002403:Cathepsins; D007703:Peptidyl-Dipeptidase A; D001121:Lysine Carboxypeptidase; D012697:Serine Endopeptidases; C534094:CTSG protein, human; D056649:Cathepsin G; C534097:Ctsg protein, rat; D005341:Fibrinolysin; D010434:Pepsin A; D012083:Renin; D002402:Cathepsin D; C031375:pepstatin