Biochemical studies on siphonaria (Gastropoda: Pulmonata) from the Karachi Coast of North Arabian Sea

The present study showed the occurrence of three species of siphonaria,namely,s. ashgar,s,belcheri and s. kurracheensis on the rocky coast of mubarak village,karachi,pakistan. keeping in view the biomedical interest in the high molecular mass hemocyanin of the marine mollusc,the study provides for the first time,the basic knowledge about the presence and chemical composition of oxygen transport protein hemocyanin in siphonaria species. the tissue homogenates of s. ashgar,s. belcheri and s. kurracheensis when subjected to polyacrylmaide gel electrophoresis under dissociating conditions showed one major band (ca. 400kda) which corresponds to two hemocyanin subunits (named as siphonaria subunit s1 and s2). under reducing conditions this band splits into three major bands,one major approximately 400kda corresponding to the subunit s1,while s2 splits to produce two i.e. a 280kda fragment s2.1 (corresponding to six-fus) and the other 100-120kda fragment s2.2 (corresponding to two-fus). the size exclusion and ion-exchange chromatography results further revealed two specific major peaks corresponding to the two hemocyanin subunits. we conclude that the subunit composition of hemocyanin from siphonaria resembles to the hemocyanin of other reported gastropods and thus could also be subjected for further immunological investigations for their possible biomedical application. © 2011 zoological society of pakistan.