Chemical Synthesis of the Highly Hydrophobic Antiviral Membrane-Associated Protein IFITM3 and Modified Variants

Angew Chem Int Ed Engl. 2017 Oct 2;56(41):12639-12643. doi: 10.1002/anie.201707554. Epub 2017 Sep 7.

Abstract

Interferon-induced transmembrane protein 3 (IFITM3) is an antiviral transmembrane protein that is thought to serve as the primary factor for inhibiting the replication of a large number of viruses, including West Nile virus, Dengue virus, Ebola virus, and Zika virus. Production of this 14.5 kDa, 133-residue transmembrane protein, especially with essential posttranslational modifications, by recombinant expression is challenging. In this report, we document the chemical synthesis of IFTIM3 in multi-milligram quantities (>15 mg) and the preparation of phosphorylated and fluorescent variants. The synthesis was accomplished by using KAHA ligations, which operate under acidic aqueous/organic mixtures that excel at solubilizing even the exceptionally hydrophobic C-terminal region of IFITM3. The synthetic material is readily incorporated into model vesicles and forms the basis for using synthetic, homogenous IFITM3 and its derivatives for further studying its structure and biological mode of action.

Keywords: IFITM3; KAHA ligation; chemical protein synthesis; membrane proteins; protein modifications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Chemistry Techniques, Synthetic / methods
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Membrane Proteins / chemical synthesis*
  • Membrane Proteins / chemistry
  • Models, Molecular
  • Phosphorylation
  • RNA-Binding Proteins / chemical synthesis*
  • RNA-Binding Proteins / chemistry

Substances

  • Fluorescent Dyes
  • IFITM3 protein, human
  • Membrane Proteins
  • RNA-Binding Proteins