Isolation of Carp Myosin Rod and Its Structural Stability.

Abstract

Carp myosin rod was isolated from the chymotryptic digest of myosin by using DEAE-Toyopearl chromatography. The carp rod thus prepared was very similar to rabbit rod in its molecular mass, viscosity, sedimentation velocity, and amino acid composition. Changes in tryptophan fluorescence intensity indicated that carp rod more easily unfolded upon addition of urea or guanidine-HCI, and thus was structurally less stable than rabbit rod. It was found that the addition of 8-anilino-1-naphthalene sulfonate (ANS) to carp rod solution resulted in no change in fluorerescence intensity, providing no information on its structural stability. However, ANS was an excellent probe for detecting the structural change of myosin subfragment-1 (S-1) portion; namely carp S-1 required a lower urea concentration than rabbit S-1 for inducing an increase in the ANS fluorescence intensity.