title: Rotational orientation of monomers within a designed homo-oligomer transmembrane helical bundle.
abstract: A peptide designed to form a homo-oligomeric transmembrane helical bundle was reconstituted into lipid bilayers and studied by using (2)H NMR (nuclear magnetic resonance) with magic angle spinning to confirm that the helical interface corresponds to the interface intended in the design. The peptide belongs to a family of model peptides derived from a membrane-solubilized version of the water-soluble coiled-coil GCN4-P1. The variant studied here contains two asparagines thought to engage in interhelical hydrogen bonding critical to the formation of a stable trimer. For the NMR studies, three different peptides were synthesized, each with one of three consecutive leucines in the transmembrane region deuterium labeled. Prior to NMR data collection, polarized infrared spectroscopy was used to establish that the peptides were reconstituted in lipid bilayers in a transmembrane helical conformation. The (2)H NMR line shapes of the three different peptides are consistent with a trimer structure formed by the designed peptide that is stabilized by inter-helical hydrogen bonding of asparagines at positions 7 and 14.
authors.affiliation: Department of Chemistry, Swarthmore College, Swarthmore, PA 19081, USA. khoward1@swarthmore.edu
authors.forename: Kathleen P
authors.initials: KP
authors.lastname: Howard
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Evan
authors.initials: E
authors.lastname: Crocker
authors.forename: Vikas
authors.initials: V
authors.lastname: Nanda
authors.forename: James
authors.initials: J
authors.lastname: Lear
authors.forename: William F
authors.initials: WF
authors.lastname: Degrado
authors.forename: Steven O
authors.initials: SO
authors.lastname: Smith
mesh_terms: D000595:Amino Acid Sequence; D019295:Computational Biology; D003903:Deuterium / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry; D017433:Protein Structure, Secondary; D012399:Rotation; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D008565:Membrane Proteins; D010455:Peptides; D003903:Deuterium
references.citation: J Magn Reson. 2000 Dec;147(2):296-330
references.pmid: 11097821
references.citation: Nature. 1992 Apr 9;356(6369):539-42
references.pmid: 21488406
references.citation: Biochemistry. 2001 May 29;40(21):6352-60
references.pmid: 11371197
references.citation: Biophys J. 2002 May;82(5):2476-86
references.pmid: 11964235
references.citation: Biophys J. 2002 Sep;83(3):1613-9
references.pmid: 12202385
references.citation: Protein Sci. 2003 Apr;12(4):647-65
references.pmid: 12649422
references.citation: Biochemistry. 2003 Jun 3;42(21):6400-7
references.pmid: 12767221
references.citation: Protein Sci. 2004 Feb;13(2):555-9
references.pmid: 14739334
references.citation: J Mol Biol. 1981 Jan 5;145(1):215-50
references.pmid: 7265198
references.citation: Proc Natl Acad Sci U S A. 1982 Jan;79(2):386-9
references.pmid: 6952191
references.citation: Methods Enzymol. 1989;176:376-86
references.pmid: 2811694
references.citation: Biochemistry. 1994 May 24;33(20):6334-41
references.pmid: 8193149
references.citation: Biophys J. 1994 May;66(5):1335-40
references.pmid: 8061189
references.citation: J Biol Chem. 1996 Mar 8;271(10):5941-6
references.pmid: 8621468
references.citation: Biochemistry. 1996 May 28;35(21):6955-62
references.pmid: 8639647
references.citation: J Mol Biol. 1997 Apr 18;267(5):1268-82
references.pmid: 9150411
references.citation: Curr Opin Struct Biol. 1997 Aug;7(4):486-94
references.pmid: 9266169
references.citation: Proc Natl Acad Sci U S A. 1997 Oct 14;94(21):11301-6
references.pmid: 9326604
references.citation: Q Rev Biophys. 1997 Nov;30(4):365-429
references.pmid: 9634652
references.citation: Biochim Biophys Acta. 1999 Jul 6;1422(2):105-85
references.pmid: 10393271
references.citation: Curr Opin Struct Biol. 1999 Aug;9(4):509-13
references.pmid: 10449371
references.citation: Proc Natl Acad Sci U S A. 2001 Feb 27;98(5):2250-5
references.pmid: 11226225