Primary structure of hemoglobin from cobra Naja naja naja.

Cobra snake Naja naja naja hemoglobin shows four bands on Triton electrophoresis. We present the primary structure of one alpha and one beta chain. The separation of polypeptide chains was achieved by ion exchange chromatography on carboxymethyl cellulose column. The amino acid sequence was established by automatic Edman degradation of the native chains and tryptic and hydrolytic peptides in a gas-phase sequencer. The structural data are compared with those of human and other reptile hemoglobins and reveal not only large variations from human but within reptiles. The amino acid exchanges involve several subunit contacts and heme binding sites. This is the first study on the hemoglobin of a land snake. There are only two amino acid sequences of sea snake hemoglobin (Microcephalophis gracilis gracilis and Liophis miliaris) reported in the literature.