The Amino Acid Sequence of the Monomeric Hemoglobin Component from the Bloodworm, G&era dibranchiata*

The complete ammo acid sequence of 147 residues has been determined for the major monomeric component of the hemoglobin of the bloodworm, Glycera dibranchiata. The residues at 34 sites (23 %) appear to be identical with those in sperm whale myoglobin. Of the 7 “invariant” residues found in vertebrate hemoglobins only three are present in this molecule: the glycine and phenylalanine residues at positions 27 (B6) and 45 (CDl), respectively, and the proximal heme-linked histidyl residue; the distal heme-linked histidine in vertebrate hemoglobins has been replaced by leucine.