A cardiac tissue-specific binding agent of troponin I

Abstract

A fluorescently labeled, biphenylalanine-rich peptide was identified as a cTnI-specific binding agent with preferential staining affinity to myocardium tissues and extremely low staining to other stromal components. Fluorescence images demonstrate that this new peptide is an excellent contrast agent useful for examining troponin I structural distribution and expression density within heart tissue sections. It provides clear contrast between myocardial cells and the surrounding collagen matrix.

Exploring the structural requirements of collagen‐binding peptides

“…C1 is primarily composed of 16 amino acid residues, with an unnatural Bip at the C‐terminus, cyclized via a disulfide bond between two cysteine residues at positions 4 and 13. Previously, we demonstrated the critical role of Bip residue in cTnI recognition . To investigate the structural effect of the lead Bip containing peptide C1, a series of structurally related peptides were prepared (Figure ).…”

“…Previously, we demonstrated the critical role of Bip residue in cTnI recognition. 9 To investigate the structural effect of the lead Bip containing peptide C1, a series of structurally related peptides were prepared ( Figure 1). To examine the sequence preferences and the contribution of the Bip residue, peptides C2 and C3 were designed by reordering the amino acid sequence (C2) and eliminating Bip from the C-terminus (C3).…”

“…In conjunction with a myocyte targeting probe, detailed architecture of cardiovascular fibrosis could be clearly visualized. This myocyte targeting probe is a novel peptide‐based molecule comprising three biphenylalanine (Bip) residues that shows distinct binding selectivity to cardiac troponin I (cTnI) …”

“…This myocyte targeting probe is a novel peptide-based molecule comprising three biphenylalanine (Bip) residues that shows distinct binding selectivity to cardiac troponin I (cTnI). 9 Several collagen-binding proteins, including CNA35 used in our prior study, have been described. 8,[10][11][12][13] With an appropriate fluorescent label, collagen deposition within ECM could be clearly visualized in histological sections.…”

Development of a Troponin-Specific Probe for Early Detection of Cardiac Injuries

“…It is released into the bloodstream subsequently to heart damage; for this reason, it is widely used as a biomarker in the early detection of myocardial injuries [1,2]. Recently a novel peptide termed myocyte targeting peptide (MTP, Figure 1), which has unusual affinity to cardiomyocytes was identified by us [3,4]. This prototype MTP contains three residues of the non-natural amino acid biphenylalanine (Bip) and its selectivity towards cardiac tissues is thought to be due to the ability of Bip to bind cTnI.…”