The protein Troponin I is a component of the heteromeric protein complex responsible for regulating both skeletal and cardiac muscle contraction. Troponin complex is made up of three parts: troponin I (TnI), troponin T (TnT), and troponin C (TnC). Each of these proteins has a particular function. TnI is the inhibitory component that confers calcium-sensitivity to the ATPase activity of the myofibril contractile apparatus.
