Oxygen transport proteins: I. Structure and organization of hemocyanin from scorpion (Buthus sindicus)

Scorpions are regarded as the oldest terrestrial arthropods. Scorpion Buthus sindicus (Buthidae) is commonly found in Pakistan and the Mediterranean region. The hemolymph of most arthropods contains large multisubunit, extracellular metalloprotein commonly known as hemocyanin which performs the important function of oxygen transport. The literature available to date shows that no attempt has been made to study hemocyanins or hemolymph proteins from this species. This communication presents the isolation, characterization and partial structural studies on hemocyanin from scorpion Buthus sindicus. (1) The hemolymph was collected by cardiac puncture, centrifuged and subjected to polyacrylamide gel electrophoresis and isoelectric focussing. (2) Crude hemolymph was subjected to gel filtration and high performance ion-exchange chromatography. (3) Purified hemocyanin subunits Bsin 1, 2 and 3 have been analysed for their amino acid composition and N-terminal sequence. The sequence homology was determined by comparison with other arthropod hemocyanin. The results are discussed.