A few different types of troponins exist—troponin I, troponin T, and troponin C. Each individual subunit has a unique functionality: Troponin T binds the troponin parts to tropomyosin, troponin I inhibits the interaction of myosin with actin, and troponin C is made up of the binding web sites for Ca2+ that assists initiate contraction. [1]Dukunga