Identification of troponin C antagonists from a phage-displayed random peptide library.

Published

Journal Article

Affinity purification of a phage-displayed library, expressing random peptide 12-mers at the N terminus of protein III, has identified 10 distinct novel sequences which bind troponin C specifically. The troponin C-selected peptides yield a consensus binding sequence of (V/L)(D/E)XLKXXLXXLA. Sequence comparison revealed as much as a 62.5% similarity between phiT5, the peptide sequence of the phage clone with the highest level of binding to troponin C, and the N-terminal region of troponin I isoforms. Biotinylated peptides corresponding to library-derived sequences and similar sequences from various isoforms of troponin I were synthesized shown to bind troponin C specifically. Alkaline phosphatase fusion proteins of two of the phage clone sequences bound troponin C specifically, and were specifically competed by both library-derived and native troponin I peptides. Measurement of equilibrium dissociation constants of the peptides by surface plasmon resonance yielded dissociation constants for troponin C as low as 0.43 microM for pT5; in contrast, dissociation constants for calmodulin were greater than 6 microM for all peptides studied. Nondenaturing polyacrylamide gel electrophoresis demonstrated that pT5 formed a stable complex with troponin C in the presence of calcium. We also found that the pT5 peptide inhibited the maximal calcium-activated tension of rabbit psoas muscle fibers.

Full Text

Duke Authors

Cited Authors

  • Pierce, HH; Schachat, F; Brandt, PW; Lombardo, CR; Kay, BK

Published Date

  • September 4, 1998

Published In

Volume / Issue

  • 273 / 36

Start / End Page

  • 23448 - 23453

PubMed ID

  • 9722581

Pubmed Central ID

  • 9722581

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.273.36.23448

Language

  • eng

Conference Location

  • United States