Epitope mapping of anti-troponin I monoclonal antibodies

Two groups of monoclonal antibodies (MAbs) specific to human cardiac troponin I (cTnI) were generated by immunization of mice by isolated cTnI (group I, 16 MAbs) or by the whole troponin complex (group II, 15 MAbs). Two sets of overlapping decapeptides covering the complete sequence of cTnI were prepared and used for epitope mapping by SPOT technique. Majority of MAbs (28 out of 31) interacts with synthetic peptides thus indicating that they recognize liner epitopes. MAbs raised against isolated cTnI preferentially recognize epitopes located at the N- or C-terminal ends of cTnI. Nine out of fifteen MAbs raised against whole troponin complex interact with epitopes located in the N-terminal part of cTnI. Generation of MAbs recognizing both isolated cTnI and cTnI inside of troponin complex and mapping their epitopes provides reliable detection of TnI in serum of patients with acute myocardial infarction.