Change in Titin Position in Postmortem Bovine Muscle

ABSTRACT Myofibrils were prepared from bovine psoas muscles removed from the carcass at 3 and 48 hr postmortem and subsequently stained with a monoclonal antibody against titin. The antibody stained 2 bands per sarcomere (perpendicular to the fiber direction) in myofibrils from 3‐hr muscle but often revealed 4 bands per sarcomere in the 48‐hr samples. The results suggested that (1) the titin shape might be altered within the first 2 days postmortem, or (2) proteolysis of titin or a protein to which it was attached occurred.