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Fourier transform infrared spectroscopic study on the Ca 2+ ‐bound coordination structures of synthetic peptide analogues of the calcium‐binding site III of troponin C
Author(s) -
Nara Masayuki,
Morii Hisayuki,
Yumoto Fumiaki,
Kagi Hiroyuki,
Tanokura Masaru
Publication year - 2006
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20477
Subject(s) - chemistry , peptide , troponin c , denticity , stereochemistry , crystallography , residue (chemistry) , infrared spectroscopy , crystal structure , troponin i , biochemistry , organic chemistry , psychology , psychiatry , myocardial infarction
The coordination structures of Ca 2+ ion bound to synthetic peptide analogues of the calcium‐binding site III of rabbit skeletal muscle troponin C (TnC) were investigated by Fourier transform infrared (FTIR) spectroscopy. The region of the COO − antisymmetric stretching vibration provides information about the coordination modes of a COO − group to a metal ion. The 34‐residue peptide corresponding to the EF hand motif (helix–loop–helix) showed a band at 1552 cm −1 in the Ca 2+ ‐loaded state, indicating that the side‐chain COO − group of Glu at the 12th position serves as a ligand for Ca 2+ in the bidentate coordination mode. On the other hand, the 13‐residue peptide (Ac‐DRDADGYIDAEEL‐NH 2 ) containing the Ca 2+ ‐binding site III (DRDADGYIDAEE) did not show such spectral patterns in the Ca 2+ ‐loaded state, meaning that shorter synthetic peptide corresponding to the site III has less or no affinity for Ca 2+ . It was found that the 17‐residue peptide (Ac‐DRDADGYIDAEELAEIF‐NH 2 ) is the minimum peptide necessary for the interaction of side‐chain COO − of Glu at the 12th position with Ca 2+ in the bidentate coordination mode. We discuss the relationship between the amino acid length of synthetic peptide analogues and the formation of Ca 2+ ‐bound coordination structure. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 339–343, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com