Cardiac troponin I (cTnI) is a subunit of the troponin complex in cardiac muscle thin filaments, which plays a role in muscle activity.1 It is encoded by TNNI3 in humans and is expressed exclusively in the heart. cTnI is a multidomain protein composed of an N-terminal domain, IT-arm, inhibitory domain, regulatory domain, and C-terminal mobile domain. The N-terminal domain is exclusive to cTnI and is essential to the interaction of cTnI with troponin C and in the regulation of calcium-dependent muscle contraction. cTnI binds to actin to hold the troponin complex in place in thin myofilaments. Phosphorylation of cTnI at serines 22 and 23 in the N-terminus decreases sarcomere calcium sensitivity, promotes calcium dissociation from troponin C, and enhances diastolic relaxation.2,3 Cardiac systolic dysfunction in human and animal models of heart failure is linked to PKC phosphorylation of cTnI at serines 23, 24, 43, and 45, as well as threonine 144.3 Cayman’s Cardiac Troponin I Polyclonal Antibody can be used for Western blot (WB) applications. The antibody recognizes cTnI at approximately 25 kDa from human, mouse, and rat samples.WARNING This product is not for human or veterinary use.
