Preparation of native connectin from chicken breast muscle

Connectin, an elastic protein of striated muscle, was isolated in a native state from chicken breast muscle. Myofibrils were well washed with 5 mM NaHCO3 and extracted with 0.1 M sodium phosphate buffer, pH 5.6. After washing with water, myofibrils were extracted with 0.1 M phosphate buffer, pH 6.6. The filtrate contained native connectin. The yield of connectin was as high as 200 mg, starting from 50 g of muscle. Since connectin had been isolated only in a denatured state before, the new preparation method enables investigation of possible interactions of connectin with other myofibrillar structural proteins.