TEMPERATURE-ACCLIMATION INDUCES LIGHT-MEROMYOSIN ISOFORMS WITH DIFFERENT PRIMARY STRUCTURES IN CARP FAST SKELETAL-MUSCLE

Carp acclimated to 10 degrees C gave 69k, 66k, and 62kDa light meromyo sin (LMM) fragments In SDS-PAGE, while fish acclimated to 30 degrees C gave 74k, 69k, 66k, and 62kDa fragments. The microsequence analysis r evealed that the 69k and 66kDa components from the 10 degrees C-acclim ated carp contained an N-terminal amino acid sequence different from t hat of 62kDa. The four fragments from the 30 degrees C-acclimated carp showed the same sequence as that of the 69k and 66kDa components from the 10 degrees C-acclimated carp, except that the 2nd amino acid, Ala , of the 10 degrees C-acclimated LMM was replaced by Thr. DNA fragment s encoding an N-terminal region of LMM were amplified by PCR or revers e transcriptase PCR, demonstrating that the two acclimated groups furt her contained several amino acids substituted. (C) 1995 Academic Press , Inc.