Characterization of acetylcholinesterase from Korean electric ray and comparison withTorpedo californica

Abstract

This study has been undertaken to examine the acetylcholinesterase (AChE) of electric organ from korean electric ray (Narke japonica). Korean electric ray was caughted at Chungmu sea and transported to the laboratory, where electric organs were removed and stored at −70°C until used. Acetylcholinesterase(AChE) of electric organ was purified by affinity column that was prepared with dicaproyl-methylpyridinium linked to Sepharose 4B. Upon purification, the specific activities in Ellman unit were increased by 52 and 39 times for high salt soluble AChE (HSSE, 870.86 ΔOD/min/gram of tissue) and detergent soluble AChE(DSE, 105.42 ΔOD/min/gram of tissue), respectively. Each subunit of AChE separated by SDS polyacrylamide gel electrophoresis(SDS-PAGE) was transferred to immobilon P by western blotting and detected by mAbs raised against each subunit of AChE from electric organ ofTorpedo californica. Collagenic tail of AChE fromNarke japonica were identified by monoclonal antibody specific to collagenic tail of AChE fromTorpedo californica, likewise 103Kd protein of AChE fromNarke japonica was detected by monoclonal antibody specific to 103Kd of AChE fromTorpedo californica. However, molar ratio of three subunits of AChE fromNarke japonica is different from that ofTorpedo californica. Furthermore, catalytic subniit of AChE fromNarke japonica was not identified by monoclnal antibody specific to catalytic subunit of AChE fromTorpedo californica. These results showed differences in molecular structure of AChE fromNarke japonica and AChE fromTorpedo californica eventhough they showed same enzymatic activities.