The bound nucleotide of the isolated myofibril

Abstract

A non-enzymic method for the isolation of myofibrils from rabbit skeletal muscle was descr. Myofibrils from cardiac and skeletal muscle of the rabbit and skeletal muscle of the rat contained 90-140 [mu]g. of acid-labile P/g. Similar values were obtained with rigor muscle. The acid-labile P of myofibrils isolated from rabbit muscle arises from adeno-sinediphosphate, and to a lesser extent, ATP. These nucleotides are bound to the myofibril in such a way that they are not acted upon by the enzymes occurring in myofibrils which normally attack them.