Characterization of serum cholinesterase variants by kinetic analysis and isoelectric focusing

Serum cholinesterase enzyme (E.C. 3.1.1.8) shows a considerable degree of genetically determined heterogeneity. In this communication we describe some kinetic properties of serum cholinesterase variants (Km and Vmax) from individuals predisposed to prolonged apneic periods after administration of the anesthetic, succinylcholine. Isoelectric focusing, in a narrow pH range (pH 4-6) of sera from normal and atypical phenotypes permitted the detection of differences in protein bands near the isoelectric pH of the enzyme.