Enolase: human tissue distribution and evidence for three different loci.

Four different cellogel electrophoretic patterns of enolase were found in human tissue extracts. They consisted of: (A) one strongly stained band (I) and two minor bands (II and III) found in haemolysates, white cell, skin fibroblast and kidney extracts; (B) a three-banded pattern in brain resembling that of haemolysates except for heavier concentrations of bands II and III; (C) a single component corresponding to band I, found in liver, heart, intestine spleen and placenta; (D) a single band with slightly faster mobility than band I, found in adult muscle extracts. The haemolysate of an individual with the heterozygous ENO1/ENO2 genotype had a triple banded pattern replacing band I, a double-banded pattern replacing band II and a single weakly staining band III. This finding, as well as the results of dissociation and recombination experiments, supports the hypothesis that the enzyme is a dimer formed by random interaction of two polypeptide chains (alpha and beta) synthesized by two independent gene loci (ENO1 and ENO2). Evidence for a third locus, ENO3, is supplied by the electrophoretic pattern of muscle extracts.