Effects of detergent alkyl chain length and chemical structure on the properties of a micelle-bound bacterial membrane targeting peptide.
The effects of phospholipid or detergent chain length on the structure and translational diffusion coefficient of the membrane-targeting peptide corresponding to the N-terminal amphipathic sequence of Escherichia coli enzyme IIA(Glc) were investigated by nuclear magnetic resonance (NMR) spectroscopy. Three anionic phospholipids (dihexanoyl phosphatidylglycerol, dioctanoyl phosphatidylglycerol, and didecanoyl phosphatidylglycerol) and four lipid-mimicking anionic detergents (sodium hexanesulfonate, 2,2-dimethyl-silapentane-5-sulfonate, sodium nonanesulfonate, and sodium dodecylsulfate) were evaluated. In all cases, the cationic peptide adopts an amphipathic helical structure. While the chain length of the two-chain phospholipids has a negligible effect on the peptide conformation, the effect of chain length of those single-chain detergents on the helix length is more pronounced. The diffusion coefficients of the peptide/micelle complexes were found to correlate with the chain lengths of both the lipid and the detergent groups. Taken together, short-chain anionic phospholipids are proposed to be useful membrane-mimetic models for the structural elucidation of membrane-binding peptides such as cationic antimicrobial peptides. DSS does not form micelles by itself according to the diffusion coefficient data, but it does associate with this cationic peptide. Consequently, both DSS and its analog may be chosen as NMR chemical shift reference compounds depending on the nature of the biomolecules under investigation.
Keifer
Paul A
PA
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, NE 68198-6805, USA.
Peterkofsky
Alan
A
Wang
Guangshun
G
D000473:Alkanes / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry; D003902:Detergents / Q000737:chemistry*; D004058:Diffusion; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D008823:Micelles; D019906:Nuclear Magnetic Resonance, Biomolecular; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D017433:Protein Structure, Secondary
D000473:Alkanes; D003902:Detergents; D029968:Escherichia coli Proteins; D008823:Micelles; D010743:Phospholipids; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase