what does the a-band do during muscle contraction
The M-band proteins myomesin as well as C-protein crosslink the thick filament system (myosins) and the M-band part of titin (the elastic filaments). The interaction between actin and myosin filaments in the A-band of the sarcomere is responsible for the muscle contraction (sliding filament model). [edit] Contraction Main article: Muscle contraction Upon muscle contraction, the A-bands do not change their length (1.85 micrometer in mammalian skeletal muscle) whereas the I-bands and the H-zone shorten. The protein tropomyosin covers the myosin binding sites of the actin molecules in the muscle cell.