Methot_2001_J.Biol.Chem_276_23726

Reference

Title : Structure of the pore-forming transmembrane domain of a ligand-gated ion channel - Methot_2001_J.Biol.Chem_276_23726
Author(s) : Methot N , Ritchie BD , Blanton MP , Baenziger JE
Ref : Journal of Biological Chemistry , 276 :23726 , 2001
Abstract :

The structure of the pore-forming transmembrane domain of the nicotinic acetylcholine receptor from Torpedo has been investigated by infrared spectroscopy. Treatment of affinity-purified receptor with either Pronase or proteinase K digests the extramembranous domains (roughly 75% of the protein mass), leaving hydrophobic membrane-imbedded peptides 3-6 kDa in size that are resistant to peptide (1)H/(2)H exchange. Infrared spectra of the transmembrane domain preparations exhibit relatively sharp and symmetric amide I and amide II band contours centered near 1655 and 1545 cm(-)1, respectively, in both (1)H(2)O and (2)H(2)O. The amide I band is very similar to the amide I bands observed in the spectra of alpha-helical proteins, such as myoglobin and bacteriorhodopsin, that lack beta structure and exhibit much less beta-sheet character than is observed in proteins with as little as 20% beta sheet. Curve-fitting estimates 75-80% alpha-helical character, with the remaining peptides likely adopting extended and/or turn structures at the bilayer surface. Infrared dichroism spectra are consistent with transmembrane alpha-helices oriented perpendicular to the bilayer surface. The evidence strongly suggests that the transmembrane domain of the nicotinic receptor, the most intensively studied ligand-gated ion channel, is composed of five bundles of four transmembrane alpha-helices.

PubMedSearch : Methot_2001_J.Biol.Chem_276_23726
PubMedID: 11328815

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Citations formats

Methot N, Ritchie BD, Blanton MP, Baenziger JE (2001)
Structure of the pore-forming transmembrane domain of a ligand-gated ion channel
Journal of Biological Chemistry 276 :23726

Methot N, Ritchie BD, Blanton MP, Baenziger JE (2001)
Journal of Biological Chemistry 276 :23726