MULTIPLE FORMS OF LACTATE DEHYDROGENASE AND ASPARTATE AMINOTRANSFERASE IN HERRING (CLUPEA HARENGUS HARENGUS L.)

Abstract

The distribution of isoenzymes of lactate dehydrogenase (LDH) and aspartate aminotransferase (AAT) in the tissues of 189 herring (Clupea harengus harengus L.) were examined. Starch-gel electrophoresis of the LDH isoenzymes of the herring revealed the presence of two hybrid forms representing mutant alleles at the B locus. These mutants gave rise to two genotypes, BB′ and BB″, whose LDH staining patterns revealed a binomial distribution of the tetramer combinations formed from a free and random association of the A, B, and B′, and the A, B, and B″ monomers respectively.A hybrid form of soluble AAT was found. Its electrophoretic pattern showed a 1:2:1 binomial distribution of bands. It is postulated that these bands represent AAT dimers formed from normal S and mutant S′ monomers of a heterozygous SS′ genotype. The normal homozygous SS genotype showed only one band of activity.The normal levels of LDH and AAT activity in plasma and in heart and skeletal muscles were determined. During frozen storage LDH-5 activity gradually disappeared, while LDH-1 activity changed least; LDH-1 was also most stable at higher temperatures. Frozen storage rapidly destroyed AAT activity.