Differences in conformation stability of lactate dehydrogenase from skeletal muscles of fishes adapted to different temperatures

摘要

The effect of temperature on the secondary structure of lactate dehydrogenase from skeletal muscles of loaches adapted for 25 days at 5 deg C (cold enzyme) and 18 deg C (warm enzyme) was studied. The two forms of lactate dehydrogenase have a different course of thermal denaturation, and these differences are determined by the melting of #alpha#-helical structures. The melting of #alpha#-helices of the cold enzyme exhibits a high cooperativity and occurs in a temperature range 70-85 deg C. The melting of warm lactate dehydrogenase is observed in a broader temperature (40-85 deg C) and consists of two phases: predenaturation in the range from 40 to 75 deg C and cooperative melting in tile range from 75 to 85 deg C.