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p67phox -derived self-assembled peptides prevent Nox2 NADPH oxidase activation by an auto-inhibitory mechanism

Edna Bechor1, Anat Zahavi1, Yevgeny Berdichevsky1

  • 1The Julius Friedrich Cohnheim Laboratory of Phagocyte Research, Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.

Journal of Leukocyte Biology
|July 9, 2020
PubMed

Insights

Researchers found that self-assembling peptides from p67phox inhibit Nox2-dependent NADPH oxidase activity by mimicking auto-inhibition. This novel mechanism involves specific binding and depletion of p67phox, highlighting the role of hydrophobic interactions.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cell Signaling

Background:

  • The Nox2-dependent NADPH oxidase is activated by conformational changes induced by p67phox.
  • Previous studies identified inhibitory peptides from p67phox (residues 259-279) in cell-free assays, but the mechanism was unclear.
  • An intramolecular auto-inhibitory bond in p67phox suggested a potential mechanism for peptide inhibition.

Purpose of the Study:

  • To investigate the mechanism by which p67phox-derived peptides inhibit Nox2-dependent NADPH oxidase activity.
  • To determine the key residues and structural features responsible for peptide-induced inhibition.
  • To explore the role of self-assembly and hydrophobic interactions in the inhibitory process.

Main Methods:

  • Truncation analysis of p67phox peptides to identify inhibitory sequences.
  • Assessment of oxidase activity inhibition in cell-free assays.
  • Centrifugation to pellet self-assembled peptides.
  • Analysis of peptide binding to p67phox and Nox2.
  • Scrambling and reversal of peptide sequences to assess the role of specific residues.

Main Results:

  • Inhibitory ability of p67phox peptides correlated with the presence of the hydrophobic motif 265 NIVFVL270.
  • Inhibition was exclusively observed with self-assembled peptides that pelleted upon centrifugation.
  • Self-assembled peptides inhibited oxidase activity by binding to and depleting p67phox, thus preventing its interaction with Nox2.
  • Scrambled or reversed peptides retained self-assembly and inhibitory activity, indicating hydrophobic character is key.

Conclusions:

  • Self-assembled peptides derived from p67phox can inhibit Nox2-dependent NADPH oxidase activity.
  • The mechanism involves mimicking intrinsic auto-inhibition through specific binding and depletion of p67phox.
  • Hydrophobic interactions of the 265 NIVFVL270 motif within self-assembled peptides are critical for inhibitory function.
Keywords:
NADPH oxidasecell-free assayintramolecular bondprotein- peptide interactionsynthetic peptides

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