A globular protein complex involved in muscle contraction. It occurs with tropomyosin in the thin filaments of muscle tissue.
- ‘Actin, myosin, and troponin and tropomyosin were isolated from rabbit back muscle.’
- ‘The tropomyosin and troponin proteins on the actin filament provide the switch.’
- ‘Together with the associated protein troponin, TM on actin can switch between two laterally shifted conformations.’
- ‘The onset of contractile activity involves activating troponin, the second accessory protein of thin filaments.’
- ‘The addition of regulatory proteins, troponin and tropomyosin, is known to increase the sliding speed of thin filaments in the in vitro motility assay.’
1960s: from tropomyosin + -n- + -in.