tailieunhanh - Báo cáo khoa hoc : Hatching enzyme of Japanese eel Anguilla japonica and the possible evolution of the egg envelope digestion mechanism

We purified eel hatching enzyme (EHE) from the hatching liquid of Japa-nese eelAnguilla japonicabelonging to Elopomorpha to a single band on SDS⁄PAGE. TOF-MS analysis revealed that the purified EHE contained several isozymes with similar molecular masses. | IFEBS Journal Hatching enzyme of Japanese eel Anguilla japonica and the possible evolution of the egg envelope digestion mechanism Kaori Sano1 Mari Kawaguchi1 Masayuki Yoshikawa2 Toyoji Kaneko3 Toshiomi Tanaka4 Ichiro Iuchi1 and Shigeki Yasumasu1 1 Department of Materials and Life Sciences Faculty of Science and Technology Sophia University Tokyo Japan 2 Suruga-Bay Deep Sea Water Aquaculture Research Center Shizuoka PrefecturalResearch Institute of Fishery Japan 3 Department of Aquatic Bioscience Graduate Schoolof Agriculturaland Life Sciences University of Tokyo Japan 4 Hamanako Branch Shizuoka PrefecturalResearch Institute of Fishery Japan Keywords egg envelope digestion evolution of protein function fish hatching enzyme Japanese eel ZP protein Correspondence S. Yasumasu Department of Materials and Life Sciences Faculty of Science and Technology Sophia University 7-1 Kioi-cho Chiyoda-ku Tokyo 102-8554 Japan Fax 81 3 3238 3393 Tel 81 3 3238 3270 E-mail s-yasuma@ Received 26 April 2011 revised 19 July 2011 accepted 2 August 2011 doi We purified eel hatching enzyme EHE from the hatching liquid of Japanese eel Anguilla japonica belonging to Elopomorpha to a single band on SDS PAGE. TOF-MS analysis revealed that the purified EHE contained several isozymes with similar molecular masses. Comparison of the egg envelope digestion specificities of the purified EHE and of recombinant EHE4 one of the EHE isozymes suggested that the isozymes contained in the purified EHE were functionally the same in terms of egg envelope digestion. By electron microscopy the egg envelope became swollen after treatment with the purified EHE. The EHE cleavage sites on the zona pel-lucida ZP protein of the egg envelope were located in the N-terminal repeat regions. In previous phylogenetic analysis we suggested that fishes included in Elopomorpha as basal teleosts possess a single type of hatching enzyme genes and that fishes in Otocephala