Dataset Information

NMR study on the binding of neuropeptide achatin-I to phospholipid bilayer: the equilibrium, location, and peptide conformation.

ABSTRACT: Molecular mechanism of the binding of neuropeptide achatin-I (Gly-D-Phe-Ala-Asp) to large unilamellar vesicles of zwitterionic egg-yolk phosphatidylcholine (EPC) was investigated by means of natural-abundance (13)C and high-resolution (of 0.01 Hz order) (1)H NMR spectroscopy. The binding equilibrium was found to be sensitive to the ionization state of the N-terminal NH(3)(+) group in achatin-I; the de-ionization of NH(3)(+) decreases the bound fraction of the peptide from approximately 15% to nearly none. The electrostatic attraction between the N-terminal positive NH(3)(+) group and the negative PO(4)(-) group in the EPC headgroup plays an important role in controlling the equilibrium. Analysis of the (13)C chemical shifts (delta) of EPC showed that the binding location of the peptide within the bilayer is the polar region between the glycerol and ester groups. The binding caused upfield changes Delta delta of the (13)C resonance for almost all the carbon sites in achatin-I. The changes Delta delta for the ionic Asp at the C-terminus are more than five times as large as those for the other residues. The drastic changes for Asp result from the dehydration of the ionic CO(2)(-) groups, which are strongly hydrated by electrostatic interactions in bulk water. The side-chain conformational equilibria of the aromatic d-Phe and ionic Asp residues were both affected by the binding, and the induced changes in the equilibria appear to reflect the peptide-lipid hydrophobic interactions.

SUBMITTER: Kimura T

PROVIDER: S-EPMC1304359 | biostudies-literature | 2004 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

NMR study on the binding of neuropeptide achatin-I to phospholipid bilayer: the equilibrium, location, and peptide conformation.

Kimura Tomohiro T Okamura Emiko E Matubayasi Nobuyuki N Asami Koji K Nakahara Masaru M

Biophysical journal 20040701 1

Molecular mechanism of the binding of neuropeptide achatin-I (Gly-D-Phe-Ala-Asp) to large unilamellar vesicles of zwitterionic egg-yolk phosphatidylcholine (EPC) was investigated by means of natural-abundance (13)C and high-resolution (of 0.01 Hz order) (1)H NMR spectroscopy. The binding equilibrium was found to be sensitive to the ionization state of the N-terminal NH(3)(+) group in achatin-I; the de-ionization of NH(3)(+) decreases the bound fraction of the peptide from approximately 15% to ne ...[more]

PMID: 15240472

Similar Datasets

Project description:The human voltage dependent anion channel 1 (VDAC) is a 32 kDa ?-barrel integral membrane protein that controls the transport of ions across the outer mitochondrial membrane. Despite the determination of VDAC solution and diffraction structures, a structural basis for the mechanism of its function is not yet fully understood. Biophysical studies suggest VDAC requires a lipid bilayer to achieve full function, motivating the need for atomic resolution structural information of VDAC in a membrane environment. Here we report an essential step toward that goal: extensive assignments of backbone and side chain resonances for VDAC in DMPC lipid bilayers via magic angle spinning nuclear magnetic resonance (MAS NMR). VDAC reconstituted into DMPC lipid bilayers spontaneously forms two-dimensional lipid crystals, showing remarkable spectral resolution (0.5-0.3 ppm for (13)C line widths and <0.5 ppm (15)N line widths at 750 MHz). In addition to the benefits of working in a lipid bilayer, several distinct advantages are observed with the lipid crystalline preparation. First, the strong signals and sharp line widths facilitated extensive NMR resonance assignments for an integral membrane ?-barrel protein in lipid bilayers by MAS NMR. Second, a large number of residues in loop regions were readily observed and assigned, which can be challenging in detergent-solubilized membrane proteins where loop regions are often not detected due to line broadening from conformational exchange. Third, complete backbone and side chain chemical shift assignments could be obtained for the first 25 residues, which comprise the functionally important N-terminus. The reported assignments allow us to compare predicted torsion angles for VDAC prepared in DMPC 2D lipid crystals, DMPC liposomes, and LDAO-solubilized samples to address the possible effects of the membrane mimetic environment on the conformation of the protein. Concluding, we discuss the strengths and weaknesses of the reported assignment approach and the great potential for even more complete assignment studies and de novo structure determination via (1)H detected MAS NMR.

Dataset Information

NMR study on the binding of neuropeptide achatin-I to phospholipid bilayer: the equilibrium, location, and peptide conformation.

Publications

NMR study on the binding of neuropeptide achatin-I to phospholipid bilayer: the equilibrium, location, and peptide conformation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets