Biochemical and functional characteristics of myosin from red and white muscles of chicken as influenced by nutritional stress.

Abstract

Physicochemical and functional properties of myosin from red (red-myosin) and white (white-myosin) muscles of broilers, grown at different planes of nutrition, were studied. The red- and white-myosin from well-nourished broilers exhibited characteristic difference in certain physicochemical properties. The specific viscosity of red-myosin was lower and sedimentation coefficient (s20, w) was higher than that of white-myosin. The transition of monomer⇔filament phase of white-myosin seemed to occur in a narrower range of ionic strength than that of red-myosin. Under identical conditions (ionic strength, pH, protein concentration, temperature) of the model system, white-myosin always exhibited greater gel strength than that of red-myosin. Characteristic differences were also observed in the three-dimensional structure of red- and white-myosin gel. Heat-induced gel strength of red-myosin from under-fed broilers was about 50% less than that of control, whereas the gelling property of white-myosin was not influenced by the nutritional states. Myosin from under-fed chicken had low Ca2+-activated ATPase activity, although EDTA-activated ATPase, specific viscosity, and helicity of myosin were not different between the nutritional states.