Cardiac troponin T progressively degrades after acute myocardial infarction into 23 proteolytic fragments, with major degradation sites between amino acid residues 68-69 and 189-223.
Observational (n=37)
cTnT progressively degrades after MI into 23 fragments, indicating that the central region (aar 69-158) is the most stable and promising target for total cTnT immunodetection.
BACKGROUND: Blood measurement of cardiac troponin T (cTnT) is one of the most widespread methods of acute myocardial infarction (MI) diagnosis. cTnT degradation may have a significant influence on the precision of cTnT immunodetection; however, there are no consistent data describing the level and sites of cTnT proteolysis in the blood of MI patients. In this study, we bordered major cTnT fragments and quantified their relative abundance in the blood at different times after MI. METHODS: Serial heparin plasma samples were collected from 37 MI patients 2-37 h following the onset of MI. cTnT and its fragments were studied by western blotting and immunofluorescence analysis using monoclonal antibodies specific to various cTnT epitopes. RESULTS: cTnT was present in the blood of MI patients as 23 proteolytic fragments with an apparent molecular mass of ∼ 8-37 kDa. Two major sites of cTnT degradation were identified: between amino acid residues (aar) 68 and 69 and between aar 189 and 223. Analysis of the abundance of cTnT fragments showed an increase in the fraction of free central fragments in the first few hours after MI, while the fraction of the C-terminal fragments of cTnT remained almost unchanged. CONCLUSION: cTnT progressively degrades after MI and appears in the blood as a mixture of 23 proteolytic fragments. The cTnT region approximately bordered by aar 69-158 is a promising target for antibodies used for measurement of total cTnT.
Katrukha et al. (Wed,) conducted a observational in Acute myocardial infarction (n=37). Cardiac troponin T fragment analysis was evaluated on Level and sites of cTnT proteolysis. Cardiac troponin T progressively degrades after acute myocardial infarction into 23 proteolytic fragments, with major degradation sites between amino acid residues 68-69 and 189-223.