Synthesis of a Polyhistidine-bearing Amphipol and its Use for Immobilizing Membrane Proteins

Biomacromolecules. 2015 Dec 14;16(12):3751-61. doi: 10.1021/acs.biomac.5b01010. Epub 2015 Nov 5.

Abstract

Amphipols (APols) are short amphipathic polymers that stabilize membrane proteins (MPs) in aqueous solutions. In the present study, A8-35, a polyacrylate-based APol, was grafted with hexahistidine tags (His6-tags). The synthesis and characterization of this novel functionalized APol, named HistAPol, are described. Its ability to immobilize MPs on nickel ion-bearing surfaces was tested using two complementary methods, immobilized metal affinity chromatography (IMAC) and surface plasmon resonance (SPR). Compared to a single His6-tag fused at one extremity of a MP, the presence of several His6-tags carried by the APol belt surrounding the transmembrane domain of a MP increases remarkably the affinity of the protein/APol complex for nickel ion-bearing SPR chips, whereas it does not show such a strong effect on an IMAC resin. HistAPol-mediated immobilization, which allows reversibility of the interaction and easy regeneration of the supports and dispenses with any genetic modification of the target protein, provides a novel, promising tool for attaching MPs onto solid supports while stabilizing them.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cations, Divalent
  • Chromatography, Affinity
  • Histidine / chemistry*
  • Immobilized Proteins / chemistry*
  • Membrane Proteins / chemistry*
  • Nickel / chemistry
  • Oligopeptides / chemistry*
  • Polymers / chemical synthesis*
  • Polymers / chemistry
  • Propylamines / chemical synthesis*
  • Propylamines / chemistry
  • Protein Stability
  • Solutions
  • Surface Plasmon Resonance
  • Water

Substances

  • Cations, Divalent
  • His-His-His-His-His-His
  • Immobilized Proteins
  • Membrane Proteins
  • Oligopeptides
  • Polymers
  • Propylamines
  • Solutions
  • amphipol A8-35
  • Water
  • Histidine
  • Nickel