Hemocyanins in Spiders, X. Limited Proteolysis of ChaineofEurypelmaHemocyanin and Partial Sequence of Two Large Fragments

Abstract

The polypeptide chain e of the hemocyanin from the spider E. californicum was isolated by ion exchange chromatography. Incubation of the undenatured protein with chymotrypsin [EC 3.4.21.1], subtilisin [EC 3.4.21.14] or trypsin [EC 3.4.21.4] resulted in a small number of large fragments which were easily isolated after denaturation. Of the chymotryptic peptides e-Chn-29 was N-terminal and e-Chn-42 C-terminal. These peptides were characterized by their N-terminal amino acid sequences. The N-terminal sequence of subunit e shows homologies with other arthropod hemocyanins.