A new vasopeptide formed by the action of a Murphy-Sturm lymphosarcoma acid protease on rat plasma kininogen.
A new vasoactive peptide, formed by the action of a Murphy-Sturm lymphosarcoma acid protease on rat plasma kininogen was purified by gel filtration on Sephadex G-50 (fine) and fractions assayed on the isolated rat uterus for smooth muscle stimulating activity. The most active fraction was purified further by CM-cellulose chromatography. High voltage electrophoresis showed the peptide to be one component (Mgly 2.49) with an electrophoretic mobility different from bradykinin, lysyl-bradykinin and methionyl-lysyl-bradykinin. The molecular weight of the peptide was estimated on Sephadex G-25 column to be 1460. The amino acid composition was determined and the carboxyl terminal sequence identified by carboxypeptidase Y treatment to be Pro-Phe-Arg-Leu. Dansyl-Edman procedure yielded an amino terminal sequence of Ile-Ser-Arg-Pro. The peptide produced a dose-dependent contraction of the isolated guinea pig anterior mesenteric vein and relaxed the rabbit superior mesenteric artery contracted by phenylephrine.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D010450:Endopeptidases / Q000302:isolation & purification* / Q000502:physiology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007704:Kininogens / Q000097:blood*; D008228:Lymphoma, Non-Hodgkin / Q000201:enzymology*; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D010446:Peptide Fragments / Q000378:metabolism* / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D012513:Sarcoma, Experimental / Q000201:enzymology
D000596:Amino Acids; D007704:Kininogens; D010446:Peptide Fragments; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases