title: Isolation of an electrogenic K+/Ca2+ ionophore from an ionophoroprotein of beef heart mitochondria.
abstract: A K+/Ca2+ electrogenic ionophore has been isolated from an ionophoroprotein of beef heart mitochondria and identified as a neutral peptide of molecular weight 1600. The amino acid composition and cationic specificity of the ionophore have been determined. The free ionophore was released from the ionophoroprotein as a consequence of tryptic digestion. The ionophoroprotein can be converted to an ionophoro peptide (molecular weight 5,100) by proteolysis without release of the free ionophore. The isolation of a K+/Ca2+ ionophore thus provides an introduction to the general technology of extracting ionophoro proteins and ofreleasing ionophores from these proteins by proteolytic digestion.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D007476:Ionophores; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008566:Membranes / Q000378:metabolism / Q000648:ultrastructure; D008929:Mitochondria, Heart / Q000378:metabolism*; D009124:Muscle Proteins / Q000302:isolation & purification / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
chemical_list: D007476:Ionophores; D009124:Muscle Proteins; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium
references.citation: Can J Biochem Physiol. 1959 Aug;37(8):911-7
references.pmid: 13671378
references.citation: Proc Natl Acad Sci U S A. 1977 Sep;74(9):3662-6
references.pmid: 198794
references.citation: FEBS Lett. 1977 Mar 15;75(1):281-4
references.pmid: 15866
references.citation: Proc Natl Acad Sci U S A. 1977 Jun;74(6):2241-5
references.pmid: 142250
references.citation: Ann N Y Acad Sci. 1974;242(0):389-405
references.pmid: 4279597
references.citation: Ann N Y Acad Sci. 1974 Feb 18;227:380-91
references.pmid: 4524339
references.citation: Proc Natl Acad Sci U S A. 1974 Dec;71(12):4850-4
references.pmid: 4531024
references.citation: J Membr Biol. 1974;19(1):129-40
references.pmid: 4431039
references.citation: Proc Natl Acad Sci U S A. 1971 Sep;68(9):2037-41
references.pmid: 5289363
references.citation: Proc Natl Acad Sci U S A. 1975 Mar;72(3):896-900
references.pmid: 1055388
references.citation: Ann N Y Acad Sci. 1975 Dec 30;264:98-111
references.pmid: 1062966
references.citation: J Biol Chem. 1976 Mar 10;251(5):1326-32
references.pmid: 1254569
references.citation: Biochem Biophys Res Commun. 1971 Apr 2;43(1):28-35
references.pmid: 5579947