Heme A of cytochrome c oxicase. Structure and properties: comparisons with hemes B, C, and S and derivatives.

Heme A, isolated from bovine heart muscle by procedures which include extractions into pyridine/chloroform and two-phase, liquid-liquid chromatography on Celite, has been converted to several derivatives. Examination of the proton nuclear magnetic resonance (PMR) spectra and other properties of these derivatives reveals heme A to be the iron complex of 8-formyl-6,-m-bis(2''-hydroxycarbonylethyl)-2-(1'-hydroxy-5',9',13'-trimethyl-4',8',12'-trans,trans-tetradecatrienyl)-1,3,5-trimethyl-4-vinylporphin. Substituents at the 2,4, and 8 positions are replaced by hydrogen in a resorcinol melt to give cytodeuteroporphin (8-demethyldeuteroporphyrin IX)...