Pflügers Archiv - European Journal of Physiology

, Volume 456, Issue 6, pp 1085–1095

Oxidation of multiple methionine residues impairs rapid sodium channel inactivation

  • Mario Kassmann
  • Alfred Hansel
  • Enrico Leipold
  • Jan Birkenbeil
  • Song-Qing Lu
  • Toshinori Hoshi
  • Stefan H. Heinemann
Ion Channels

DOI: 10.1007/s00424-008-0477-6

Cite this article as:
Kassmann, M., Hansel, A., Leipold, E. et al. Pflugers Arch - Eur J Physiol (2008) 456: 1085. doi:10.1007/s00424-008-0477-6

Abstract

Reactive oxygen species (ROS) readily oxidize the sulfur-containing amino acids cysteine and methionine (Met). The impact of Met oxidation on the fast inactivation of the skeletal muscle sodium channel NaV1.4 expressed in mammalian cells was studied by applying the Met-preferring oxidant chloramine-T or by irradiating the ROS-producing dye Lucifer Yellow in the patch pipettes. Both interventions dramatically slowed down inactivation of the sodium channels. Replacement of Met in the Ile–Phe–Met inactivation motif with Leu (M1305L) strongly attenuated the oxidizing effect on inactivation but did not eliminate it completely. Mutagenesis of Met1470 in the putative receptor of the inactivation lid also markedly diminished the oxidation sensitivity of the channel, while that of other conserved Met residues in intracellular linkers connecting the membrane-spanning segments (442, 1139, 1154, 1316, 1469) were of minor importance. The results of mutagenesis, assays of other NaV channel isoforms (NaV1.2, NaV1.5, NaV1.7), and the kinetics of the oxidation-induced removal of inactivation collectively indicate that multiple Met residues need to be oxidized to completely impair inactivation. This arrangement using multiple Met residues confers a finely graded oxidative modulation of NaV channels and allows organisms to adapt to a variety of oxidative stress conditions, such as ischemic reperfusion.

Keywords

Sodium channel Na+ channel Inactivation Methionine oxidation Chloramine-T Lucifer Yellow Patch clamp 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Mario Kassmann
    • 1
  • Alfred Hansel
    • 1
  • Enrico Leipold
    • 1
  • Jan Birkenbeil
    • 1
  • Song-Qing Lu
    • 1
  • Toshinori Hoshi
    • 2
  • Stefan H. Heinemann
    • 1
  1. 1.Center for Molecular Biomedicine, Department of BiophysicsFriedrich Schiller University JenaJenaGermany
  2. 2.Department of PhysiologyUniversity of PennsylvaniaPhiladelphiaUSA