Structure-Function Analysis of a Phage Display-Derived Peptide That Binds to Insulin-like Growth Factor Binding Protein 1

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• 作者：Nicholas J. Skelton ; Yvonne M. Chen ; Nathan Dubree ; Clifford Quan ; David Y. Jackson ; Andrea Cochran ; Kerry Zobel ; Kurt Deshayes ; Manuel Baca ; M. Teresa Pisabarro ; and Henry B. Lowman
• 刊名：Biochemistry
• 出版年：2001
• 出版时间：July 24, 2001
• 年：2001
• 卷：40
• 期：29
• 页码：8487 - 8498
• 全文大小：582K
• 年卷期：v.40,no.29(July 24, 2001)
• ISSN：1520-4995

文摘

Highly structured, peptide antagonists of the interaction between insulin-like growth factor 1(IGF-I) and IGF binding protein 1 (IGFBP-1) have recently been discovered by phage display of naïvepeptide libraries [Lowman, H. B., et al. (1998) Biochemistry 37, 8870-8878]. We now report a detailedanalysis of the features of this turn-helix peptide motif that are necessary for IGFBP-1 binding andstructural integrity. Further rounds of phage randomization indicate the importance of residues contributingto a hydrophobic patch on one face of the helix. Alanine-scanning substitutions confirm that the hydrophobicresidues are necessary for binding. However, structural analysis by NMR spectroscopy indicates thatsome of these analogues are less well folded. Structured, high-affinity analogues that lack the disulfidebond were prepared by introducing a covalent constraint between side chains at positions i and i + 7 ori + 8 within the helix. Analogues based on this scaffold demonstrate that a helical conformation is presentin the bound state, and that hydrophobic side chains in this helix, and residues immediately preceding it,interact with IGFBP-1. By comparison of alanine scanning data for IGF-I and the turn-helix peptide, wepropose a model for common surface features of these molecules that recognize IGFBP-1.