Variation of proteins in myofibrils and connective tissue of chicken red and white skeletal muscles influenced by under-nutrition.

Abstract

The influence of under-nutrition (sub-maintenance feeding) and ad libitum feeding on myofibrillar and connective tissue (collagen-like) proteins of red (leg) and white (breast) muscle of growing broilers was studied. The content of 0.3 m KCl-extractable myofibrillar proteins was lower, and that of 6 m guanidine-HCl- and 1% Triton X-100-soluble proteins and connective tissue proteins was higher in red than in white muscle of ad libitum fed broilers. The relative amount of some specific proteins in 0.3 M KCl-, 0.6 m KI-, and Triton X-100-extracts differed by more than 20 to 50% between red and white muscle.Under-nutrition caused some decrease in KCl-extractable proteins of red muscle, and an increase in the connective tissue content of red muscle and in KI-, guanidine-HCl-extractable proteins, and connective tissue of white muscle. SDS-polyacrylamide gel electrophoretograms of 0.3 m KCl extracts showed that the relative concentration of 95 K protein (α-actinin) in both muscles and 59 K protein in red muscle...