Role of human Hv1 channels in sperm capacitation and white blood cell respiratory burst established by a designed peptide inhibitor

  • Proc Natl Acad Sci U S A. 2018 Dec 11;115(50):E11847-E11856. doi: 10.1073/pnas.1816189115.
Ruiming Zhao  1  2  3 ,  Kelleigh Kennedy  1 ,  Gerardo A De Blas  4 ,  Gerardo Orta  5 ,  Martín A Pavarotti  4 ,  Rodolfo J Arias  4 ,  José Luis de la Vega-Beltrán  5 ,  Qufei Li  6 ,  Hui Dai  1  2  3 ,  Eduardo Perozo  6 ,  Luis S Mayorga  4 ,  Alberto Darszon  5 ,  Steve A N Goldstein  7  2  3
Affiliations
  • 1. Department of Biochemistry, Brandeis University, Waltham, MA 02453.
  • 2. Department of Pediatrics, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153.
  • 3. Department of Cell and Molecular Physiology, Loyola University Chicago Stritch School of Medicine, Maywood, IL 60153.
  • 4. Instituto de Histología y Embriología de Mendoza (Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional de Cuyo), School of Medicine, National University of Cuyo, Mendoza CP 5500, Argentina.
  • 5. Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, 62250 Morelos, México.
  • 6. Department of Biochemistry and Molecular Biology, Gordon Center for Integrative Science, University of Chicago, Chicago, IL 60637.
  • 7. Department of Biochemistry, Brandeis University, Waltham, MA 02453; [email protected].
PMID: 30478045 DOI: 10.1073/pnas.1816189115
Abstract

Using a de novo peptide inhibitor, Corza6 (C6), we demonstrate that the human voltage-gated proton channel (hHv1) is the main pathway for H+ efflux that allows capacitation in sperm and permits sustained Reactive Oxygen Species (ROS) production in white blood cells (WBCs). C6 was identified by a phage-display strategy whereby ∼1 million novel peptides were fabricated on an inhibitor cysteine knot (ICK) scaffold and sorting on purified hHv1 protein. Two C6 peptides bind to each dimeric channel, one on the S3-S4 loop of each voltage sensor domain (VSD). Binding is cooperative with an equilibrium affinity (Kd) of ∼1 nM at -50 mV. As expected for a VSD-directed toxin, C6 inhibits by shifting hHv1 activation to more positive voltages, slowing opening and speeding closure, effects that diminish with membrane depolarization.

Keywords
C6; ICK; TIRF; proton channel; venom.
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