Characterization of the direct interaction between KcsA-Kv1.3 and its inhibitors

Biochim Biophys Acta. 2015 Oct;1848(10 Pt A):1974-80. doi: 10.1016/j.bbamem.2015.06.011. Epub 2015 Jun 12.

Abstract

Integral membrane proteins (IMPs) are of therapeutic interest and are targeted by a majority of approved drugs. It's difficult to express, purify, and maintain the functional conformation of IMPs. Nanodisc presents a reliable method to solubilize and stabilize IMPs in detergent-free condition. In this study, we demonstrate the assembly and purification of a chimeric ion channel, KcsA-Kv1.3 Nanodisc. We further detail biophysical analysis of the assembled Nanodisc using analytical ultracentrifugation (AUC), surface plasmon resonance (SPR), and back scattering interferometry (BSI). AUC is employed to determine the molecular composition of the empty and KcsA-Kv1.3 Nanodisc. Combination of SPR and BSI overcomes each other's limitation and provides insight of equilibrium binding properties of peptide and small molecule ligands to KcsA-Kv1.3.

Keywords: Ion channel ligand binding; KcsA-Kv1.3; Nanodisc.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / antagonists & inhibitors
  • Bacterial Proteins / chemistry*
  • Binding Sites
  • Kv1.3 Potassium Channel / antagonists & inhibitors
  • Kv1.3 Potassium Channel / chemistry*
  • Molecular Sequence Data
  • Multiprotein Complexes / chemical synthesis
  • Multiprotein Complexes / ultrastructure
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure*
  • Potassium Channel Blockers / chemistry*
  • Potassium Channels / chemistry*
  • Protein Binding

Substances

  • Bacterial Proteins
  • Kv1.3 Potassium Channel
  • Multiprotein Complexes
  • Potassium Channel Blockers
  • Potassium Channels
  • prokaryotic potassium channel