The impact of antibody selection on the detection of cardiac troponin I.

Background: Cardiac troponin I (cTnI) is the current standard biomarker for diagnosing acute myocardial infarction and for risk-stratification of acute coronary syndromes in patients. However, it remains unclear how the epitope specificity of antibodies in immunoassays influences the detection of various modified forms of cTnI.

Methods: Four mouse anti-human cTnI monoclonal antibodies targeting different regions of human cTnI were chosen for immunoaffinity purification of cTnI from human and swine cardiac tissue.

Top-down quantitative proteomics identified phosphorylation of cardiac troponin I as a candidate biomarker for chronic heart failure.

The rapid increase in the prevalence of chronic heart failure (CHF) worldwide underscores an urgent need to identify biomarkers for the early detection of CHF. Post-translational modifications (PTMs) are associated with many critical signaling events during disease progression and thus offer a plethora of candidate biomarkers. We have employed a top-down quantitative proteomics methodology for comprehensive assessment of PTMs in whole proteins extracted from normal and diseased tissues.