Lactate dehydrogenase isoenzymes in Aedes aegypti

Abstract

Lactate dehydrogenase (LDH) isoenzymes from Aedes aegypti were separated by acrylamide electrophoresis. Five isoenzymes were found in the head, abdomen, and thorax with those moving fastest (LDH 1 and LDH 2) located predominantly in the head. The slow moving isoenzymes (LDH 4 and LDH 5) were found in high concentrations in both the abdomen and thorax. In whole mosquito extracts, the relative activities of LDH 1 and LDH 2 decreased while the slow moving LDH 4 and LDH 5 increased in relative activity as the mosquito became older. Following a blood meal, both the relative and specific activities of LDH 1 and LDH 2 rose sharply while the specific activity of LDH 4 and LDH 5 remained constant. It seems likely that the blood meal stimulates the genetic loci which regulate the synthesis of the H subunits of LDH. However, the loci which regulate synthesis of the M subunits do not appear to be affected.