¹H, ¹³C and ¹⁵N chemical shift assignments of Na-FAR-1, a helix-rich fatty acid and retinol binding protein of the parasitic nematode Necator americanus

Biomol NMR Assign. 2014 Apr;8(1):19-21. doi: 10.1007/s12104-012-9444-4. Epub 2012 Nov 20.

Abstract

The fatty acid and retinol-binding (FAR) proteins are a family of unusual helix-rich lipid binding proteins found exclusively in nematodes, and are secreted by a range of parasites of humans, animals and plants. Na-FAR-1 is from the parasitic nematode Necator americanus, an intestinal blood-feeding parasite of humans. Sequence-specific (1)H, (13)C and (15)N resonance assignments have been obtained for the recombinant 170 amino acid protein, using three-dimensional triple-resonance heteronuclear magnetic resonance experiments. Backbone assignments have been obtained for 99.3% of the non-proline HN/N pairs (146 out of 147). The amide resonance of T45 was not observed, probably due to rapid exchange with solvent water. A total of 96.9% of backbone resonances were identified, while 97.7% assignment of amino acid sidechain protons is complete. All Hα(166), Hβ(250) and Hγ(160) and 98.4% of the Hδ (126 out of 128) atoms were assigned. In addition, 99.4% Cα (154 out of 155) and 99.3% Cβ (143 out of 144) resonances have been assigned. No resonances were observed for the NH(n) groups of R93 NεHε, arginine, N(η1)H2, N(η2)H2, histidine N(δ1)H(δ1), N(ε1)H(ε1) and lysine N(ζ3)H3. Na-FAR-1 has a similar overall arrangement of α-helices to Ce-FAR-7 of the free-living Caeorhabditis elegans, but with an extra C-terminal helix.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbon Isotopes
  • Fatty Acids / metabolism*
  • Helminth Proteins / chemistry*
  • Hydrogen
  • Necator americanus / metabolism*
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular
  • Parasites / metabolism*
  • Protein Structure, Secondary
  • Recombinant Proteins / chemistry
  • Retinol-Binding Proteins / chemistry*

Substances

  • Carbon Isotopes
  • Fatty Acids
  • Helminth Proteins
  • Nitrogen Isotopes
  • Recombinant Proteins
  • Retinol-Binding Proteins
  • Hydrogen