Ca²⁺regulation of the cardiac thin filament

The physiological role of calcium in a cardiac myocyte is demonstrated in the coupling of excitation and contraction. Small extracellular calcium signals are amplified in the cardiac myocyte through calcium release from the sarcoplasmic reticulum. This amplified calcium signal is sensed by the thin filament heterotrimeric troponin complex. This is then transduced through a concerted series of inter- and intra-molecular conformational changes to ultimately allow the force generation required for the maintenance of normal cardiac pump function. This chapter seeks to delve into the biochemistry and biophysics that dictate the cellular physiology of the myofilaments.