Entrapment of Water at the Transmembrane Helix-Helix Interface of Quiescin Sulfhydryl Oxidase 2

Biochemistry. 2016 Mar 8;55(9):1287-90. doi: 10.1021/acs.biochem.5b01239. Epub 2016 Feb 22.

Abstract

Little is known about how a membrane can regulate interactions between transmembrane helices. Here, we show that strong self-interaction of the transmembrane helix of human quiescin sulfhydryl oxidase 2 rests on a motif of conserved amino acids comprising one face of the helix. Atomistic molecular dynamics simulations suggest that water molecules enter the helix-helix interface and connect serine residues of both partner helices. In addition, an interfacial tyrosine can interact with noninterfacial water or lipid. Dimerization of this transmembrane helix might therefore be controlled by membrane properties controlling water permeation and/or by the lipid composition of the membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Helix-Loop-Helix Motifs / physiology*
  • Humans
  • Molecular Sequence Data
  • Oxidoreductases Acting on Sulfur Group Donors / chemistry*
  • Oxidoreductases Acting on Sulfur Group Donors / genetics
  • Oxidoreductases Acting on Sulfur Group Donors / metabolism*
  • Protein Structure, Secondary
  • Water / metabolism*

Substances

  • Water
  • Oxidoreductases Acting on Sulfur Group Donors
  • QSOX2 protein, human