Proteolytic Preparation of a Heme Binding Fragment from Sperm Whale Myoglobin: Micro-Myoglobin

Summary.  Clostripain digestion of sperm whale apomyoglobin does not yield a heme binding fragment, contrary to horse heart apomyoglobin, from which mini-myoglobin has been obtained by this approach. However, in pepsin digests of sperm whale apomyoglobin we identified two fragments closely corresponding to the polypeptide encoded by the central exon of the myoglobin gene. One of these fragments consisting of 77 amino acid residues was purified. Spectroscopic data indicate that it has heme binding properties. Received October 28, 1999. Accepted November 23, 1999