RELATIONSHIP BETWEEN CONTRACTILITY AND SOME BIOCHEMICAL PROPERTIES OF MYOFIBRILS PREPARED FROM NORMAL AND PSE PORCINE MUSCLE

ABSTRACT Contractility and ATPase activity of myofibrils from normal and PSE porcine muscles were studied Studies were also made on the extractability of proteins from myofibrils isolated from normal and PSE muscles. Normal muscles contracted instantaneously after the addition of Mg 2+ ‐ATP, while PSE muscles contracted in part or did not contract. ATPase activity of myofibrils isolated from muscle having higher pH value was higher than that of myofibrils isolated from muscle having lower pH value. When using either Hasselbach‐Schneider or KI solutions to extract myofibrillar proteins, the proportion of protein extracted was significantly higher for normal muscles when compared to those from PSE muscles.