Transmembrane organization of the Na+,K+-ATPase molecule

N. Modyanov, S. Lutsenko, E. Chertova, R. Efremov, D. Gulyaev

Research output: Contribution to journalArticlepeer-review

Abstract

The organization of the hydrophobic domain of the Na,K-ATPase in the E1 and E2 form of the enzyme has been studied by labelling with two hydrophobic photoactivable reagents 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID) and 1-palmitoyl-2-[11-[4-[3-(trifluoromethyl) diazirinyl] phenyl] [2-H3]undecanoyl]-sn-glycero-3-phosphorylcholine ([3H]PTPC/11). The incorporation of the reagents into the α-subunit but not into the β-subunit in the E1-conformation was shown to be lower than that in the E2 form. This indicated the structural rearrangement of the α-subunit, which resulted in a change in the accessibility of the membrane-bound fragments for the hydrophobic labels. The set of the [125I]TID-labelled peptides of the α-subunit was shown to be the same for the E1 and E2 form of the enzyme: Asp68-Lys142, Ile265-Lys341, Val545-Lys589, Ser770-Lys826, Leu842-Arg880, Asn936-Arg972 and Met97-Arg999, which points to the different level of modification of the same fragments. The first results of molecular modelling of the spatial organization of the intramembrane part of Na+,K+-ATPase are also presented.

Original languageEnglish (US)
Pages (from-to)49-58
Number of pages10
JournalActa Physiologica Scandinavica, Supplement
Volume146
Issue number607
StatePublished - Jan 1 1992
Externally publishedYes

Keywords

  • Na,K ATPase
  • hydrophobic photolabelling
  • molecular modelling
  • protein spatial organization

ASJC Scopus subject areas

  • Physiology

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