Hypertrophic & Dilated Cardiomyopathy
Many human hypertrophic and dilated cardiomyopathies involve missense mutations in human beta-cardiac myosin. Red spheres show locations of HCM mutations and blue spheres of DCM mutations within the myosin motor domain.
From cell to sarcomere
The 100 micron long cell consists of densely packed myofibrils. The myofibrils consist of repeating 2 micron long units called sarcomeres, which contain overlapping actin-containing thin filaments and myosin-containing thick filaments.
Basic elements of the sarcomere
Thin actin-containing filaments have a 36-nm helical periodicity. In contrast, the thick myosin-containing filaments have a 42.9-nm helical repeat.