Novel cholinesterase expression in the HuH-7 cell line.

On polyacrylamide gradient gel electrophoresis, normal serum cholinesterase was separated into seven isozymes (I-VII from the anodic to the cathodic side). The enzyme of the conditioned medium of the HuH-7 cell line, established from a human hepatoma, had two main isozymes. The one migrating faster was located slightly to the cathodic side of band II of the normal serum enzyme, and the other, a slower one, electrophoresed at the same position as that of band VI of the normal serum enzyme. Aside from these two isozymes, a faint band with enzyme activity sometimes appeared at a position just cathodic or very close to the position of band I of the normal serum isozymes. The effect of some inhibitors and activators on both the normal serum enzyme and the enzyme of the conditioned medium was similar, but lectin-binding properties of the two enzymes were different with Ricinus communis agglutinin I, concanavalin A and wheat germ agglutinin. These results suggest that the difference in sugar moieties of both enzymes is expressed in D-galactose, D-mannose and N-acetylglucosamine.