HAEMPROTEINS IN HEART MICROSOMES. I. ISOLATION AND PROPERTIES OF HAEMPROTEOLIPID.

Abstract A haem-containing proteolipid was extracted with chloroform-methanol from beef-heart microsomes and purified by salting-out. The purified haem-containing proteolipid which sedimented as a single peak on ultracentrifugation in α , α ′-dichlorhydrin showed absorption bands at 278, 400, 491 and 598 mμ. It showed absorption bands of amide linkages, ester carbonyl and covalent phosphate groups in the infrared spectrum. The compound consists of approx. 35% of lipid and 65% of protein and protoheam. The protein moiety is rich in valine, leucine and acidic amino acids. Haem-containing proteolipid was extracted only from microsomes and not from mitochondria. It was found in the microsomes of beef heart, liver, spleen and probably mung bean seedlings.