Structure and Dynamics of the Hiv-1 Vpu Transmembrane Domain Revealed by Solid-state Nmr with Magic-angle Spinning.
From: Laboratory of Chemical Physics, National Institutes of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.
Biochemistry
- Publish Date: Jan 2006
- ISSN: 0006-2960
- Volume: 45
- Issue: 3
- Pages: 918-33
- Medium: Print
- Language: English
- Citation (JAMA): Sharpe Simon, Yau Wai-Ming, Tycko Robert, et al. Structure and Dynamics of the Hiv-1 Vpu Transmembrane Domain Revealed by Solid-state Nmr with Magic-angle Spinning.. Biochemistry Jan 2006;45:918-33
Abstract
We report solid-state nuclear magnetic resonance (NMR) measurements on the peptide Vpu(1-40), comprising residues 1-40 of the 81-residue type 1 integral membrane protein Vpu encoded by the HIV-1 genome. On the basis of a combination of 13C and 15N NMR chemical shifts under magic-angle spinning (MAS), effects of local mobility on NMR signal intensities, site-specific MAS NMR line widths, and NMR-detected hydrogen-deuterium exchange, we develop a model for the structure and dynamics of the Vpu(1-40) monomer in phospholipid bilayer membranes. Our data are largely consistent with earlier structural studies of Vpu peptides by Opella and co-workers, in which solution NMR and solid-state NMR without MAS were used, but our data provide new information about local variations in the degree of mobility and structural order. In addition, our data indicate that the transmembrane alpha-helix of Vpu(1-40) extends beyond the hydrophobic core of the bilayer. We find no evidence for heterogeneity in the conformation and intermolecular contacts of the transmembrane alpha-helix, with the exception of two distinct chemical shifts observed for the C alpha and C beta atoms of A18 that may reflect distinct modes of helix-helix interaction. These results have possible implications for the supramolecular structure of Vpu oligomers that form cation-selective ion channels.
Mesh Headings (Keywords): Amino Acid Sequence, Binding Sites, Cell Membrane, HIV-1, Human Immunodeficiency Virus Proteins, Isotope Labeling, Kinetics, Membrane Proteins, Models, Molecular, Molecular Sequence Data, Nuclear Magnetic Resonance, Biomolecular, Phosphorus Isotopes, Protein Structure, Tertiary, Viral Regulatory and Accessory Proteins
Check for Full Text / PubMed Unique Identifier (PMID): 16411768
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.