Honey bee odorant-binding protein 14: effects on thermal stability upon odorant binding revealed by FT-IR spectroscopy and CD measurements

Eur Biophys J. 2014 Mar;43(2-3):105-12. doi: 10.1007/s00249-013-0939-4. Epub 2013 Dec 21.

Abstract

In the present work, we study the effect of odorant binding on the thermal stability of honey bee (Apis mellifera L.) odorant-binding protein 14. Thermal denaturation of the protein in the absence and presence of different odorant molecules was monitored by Fourier transform infrared spectroscopy (FT-IR) and circular dichroism (CD). FT-IR spectra show characteristic bands for intermolecular aggregation through the formation of intermolecular β-sheets during the heating process. Transition temperatures in the FT-IR spectra were evaluated using moving-window 2D correlation maps and confirmed by CD measurements. The obtained results reveal an increase of the denaturation temperature of the protein when bound to an odorant molecule. We could also discriminate between high- and low-affinity odorants by determining transition temperatures, as demonstrated independently by the two applied methodologies. The increased thermal stability in the presence of ligands is attributed to a stabilizing effect of non-covalent interactions between odorant-binding protein 14 and the odorant molecule.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyclic Monoterpenes
  • Animals
  • Bees / chemistry
  • Bees / drug effects
  • Bees / metabolism*
  • Circular Dichroism
  • Eugenol / pharmacology
  • Hot Temperature
  • Insect Proteins / chemistry*
  • Insect Proteins / metabolism
  • Protein Binding
  • Protein Denaturation
  • Protein Stability
  • Receptors, Odorant / chemistry*
  • Receptors, Odorant / metabolism
  • Spectroscopy, Fourier Transform Infrared
  • Terpenes / pharmacology

Substances

  • Acyclic Monoterpenes
  • Insect Proteins
  • Receptors, Odorant
  • Terpenes
  • odorant-binding protein
  • Eugenol
  • geraniol