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Semi-automated Biopanning of Bacterial Display Libraries for Peptide Affinity Reagent Discovery and Analysis of Resulting Isolates
Published on: December 6, 2017
Structure-function analysis of a phage display-derived peptide that binds to insulin-like growth factor binding
N J Skelton1, Y M Chen, N Dubree
1Department of Protein Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA. skelly@gene.com
Biochemistry
|July 18, 2001
Summary
Researchers identified key features of peptide antagonists that bind to insulin-like growth factor binding protein 1 (IGFBP-1). These findings reveal structural requirements for effective IGFBP-1 binding and antagonism.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Phage display identified peptide antagonists for insulin-like growth factor 1 (IGF-I) and IGF binding protein 1 (IGFBP-1) interaction.
- Understanding the structural basis of this antagonism is crucial for developing therapeutic agents.
Purpose of the Study:
- To analyze the structural features of a turn-helix peptide motif essential for IGFBP-1 binding.
- To investigate the role of specific residues and structural integrity in peptide-IGFBP-1 interactions.
Main Methods:
- Phage randomization and alanine-scanning substitutions to identify critical residues.
- Nuclear Magnetic Resonance (NMR) spectroscopy to assess structural integrity and conformation.
- Design and synthesis of constrained analogues to stabilize helical structure.
Main Results:
- Hydrophobic residues on the helix face are crucial for IGFBP-1 binding.
- Some alanine substitutions compromised peptide folding, as shown by NMR.
- Constrained analogues confirmed a helical conformation in the bound state.
- Specific hydrophobic residues and preceding residues mediate IGFBP-1 interaction.
Conclusions:
- A helical conformation is essential for peptide antagonists binding to IGFBP-1.
- Hydrophobic interactions within the helix are critical for high-affinity binding.
- A model for common surface features recognizing IGFBP-1 was proposed by comparing IGF-I and peptide data.
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