Localization of paratropomyosin in chicken skeletal muscle myofibrils and its behavior during postmortem storage of muscles revealed by immunoelectron microscopy

摘要

Paratropomyosin is a minor myofibrillar protein which in freshly prepared myofibrils is exclusively localized at the A-I junction region of sarcomeres. We investigated the ultrastructural localization of paratropomyosin in intact and postrigor myofibrils by immunoelectron microscopy. Paratropomyosin was localized as two distinct stripes at the A-I junction in intact myofibrils. It also was localized at the position corresponding to the original A-I junction in thick filament-free myofibrils (I-Z-I brushes). However, following postmortem storage, paratropomyosin was found broadly distributed in thin filaments of myofibrils.