Hybridization Experiments Using Fish Myosin Light Chains and Desensitized Akazara Myosin

Abstract

A light chain mixture was obtained from the dorsal muscle myosin of Pacific pomfret Brama japonica and Alaska pollack Theragra chalcogramma by subsequent treatments witn 4M urea (+EDTA) and 33% (v/v) acetone. Three light chains designated LC-a, LC-b and LC-c were isolated from each mixture by DEAE-cellulose column chromatography.
LC-b of each myosin was found to bind to desensitized akazara myosin at a maximum molar ratio of 2:1, as did the molluscan regulatory light chain or rabbit DTNB-light chain.
Hybridization of each fish myosin LC-b with desensitized akazara myosin resulted in the decrease of Mg-ATPase activity in the presence and absence of Ca²⁺, along with loss of Ca²⁺ sensitivity.
It was concluded from these results that LC-b from each fish species has a similar property to that of rabbit skeletal DTNB-light chain.