Cardiac Troponin I Protein (Active)

Troponin I is one of 3 subunits that form the troponin complex of the thin filaments of striated muscle, the others are troponin T and troponin C. Human troponin I is presented in cardiac muscle tissue by a single isoform with molecular weight 23876 Da and it consists of 209 amino acid residues. It binds actin and inhibits actomyosin ATPase activity in the absence of calcium. In 2000, Labarrere et al. found that persistent elevation of cardiac troponin I levels after heart transplantation were associated with high risk for developing coronary artery disease and graft failure after cardiac transplantation. The cardiac troponin I may be a useful tool in identifying patients with heart failure who are at increased risk for progressive ventricular dysfunction and death.

Horwich, T. B., Patel, J., MacLellan, W. R., Fonarow, G. C. Cardiac troponin I is associated with impaired hemodynamics, progressive left ventricular dysfunction, and increased mortality rates in advanced heart failure. Circulation 108: 833-838, 2003. Labarrere, C. A., Nelson, D. R., Cox, C. J., Pitts, D., Kirlin, P., Halbrook, H. Cardiac-specific troponin I levels and risk of coronary artery disease and graft failure following heart transplantation. JAMA 284: 457-464, 2000.