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An internal histidine residue from the bacterial surface protein, PAM, mediates its binding to the kringle-2 domain

M M Schenone1, S E Warder, J A Martin

  • 1Department of Chemistry and Biochemistry, University of Notre Dame, IN, USA.

The Journal of Peptide Research : Official Journal of the American Peptide Society
|January 11, 2001
PubMed

Insights

Histidine 12 is crucial for peptide binding to plasminogen

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Protein-Peptide Interactions

Background:

  • Kringle domains of plasminogen are key in protein-protein interactions.
  • Lysine binding is a known interaction mechanism for kringle domains.
  • Streptococcal surface proteins can interact with host plasminogen.

Purpose of the Study:

  • Investigate the binding determinants of a peptide to a plasminogen kringle domain.
  • Identify specific amino acid residues responsible for peptide-kringle interaction.
  • Characterize the binding affinity and specificity.

Main Methods:

  • Two-dimensional Nuclear Magnetic Resonance (2D-NMR) spectroscopy to detect chemical shifts.
  • Isothermal Titration Calorimetry (ITC) to quantify binding thermodynamics.
  • Surface-Enhanced Laser Desorption Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF MS) for high-throughput screening.

Main Results:

  • 2D-NMR revealed significant kringle-induced chemical shifts in the Histidine 12 side-chain of the peptide.
  • ITC confirmed the involvement of Histidine 12 in the peptide-protein complex.
  • SELDI screening identified peptides with Histidine 12 as having the strongest binding.
  • Minor binding was observed for peptides with Lysine, Arginine, or Tryptophan at position 12.

Conclusions:

  • Histidine 12 is a primary determinant for the binding of this peptide to the plasminogen kringle domain.
  • The study elucidates a novel binding mechanism beyond lysine interactions.
  • Findings contribute to understanding pathogen-host interactions involving plasminogen.

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