Comparison of the conformation and electrostatic surface properties of magainin peptides bound to sodium dodecyl sulfate and dodecylphosphocholine micelles.
The role played by noncovalent interactions in inducing a stable secondary structure onto the sodium dodecyl sulfate (SDS) and dodecylphosphocholine (DPC) micelle-bound conformations of (Ala(8,13,18))magainin 2 amide and the DPC micelle bound conformation of magainin 1 were determined. Two-dimensional NMR and molecular modeling investigations indicated that (Ala(8,13,18))magainin 2 amide bound to DPC micelles adopts a alpha-helical secondary structure involving residues 2-16. The four C-terminal residues converge to a lose beta-turn structure. (Ala(8,13,18))magainin 2 amide bound to SDS miscelles adopts a alpha-helical secondary structure involving residues 7-18. The C- and N-terminal residues exhibited a great deal of conformational flexibility. Magainin 1 bound to DPC micelles adopts a alpha-helical secondary structure involving residues 4-19. The C-terminal residues converge to a lose beta-turn structure. The results of this investigation indicate hydrophobic interactions are the major contributors to stabilizing the induced helical structure of the micelle-bound peptides. Electrostatic interactions between the polar head groups of the micelle and the cationic side chains of the peptides define the positions along the peptide backbone where the helical structures begin and end.
Hicks
Rickey P
RP
Department of Medicinal Chemistry, Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA. Rickey.Hicks@NA.AMEDD.ARMY.MIL
Mones
Erin
E
Kim
Hanah
H
Koser
Brandon W
BW
Nichols
Daniel A
DA
Bhattacharjee
Apurba K
AK
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D001665:Binding Sites; D054806:Magainins; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008958:Models, Molecular; D010767:Phosphorylcholine / Q000031:analogs & derivatives*; D011487:Protein Conformation; D012967:Sodium Dodecyl Sulfate; D055672:Static Electricity; D013499:Surface Properties; D029867:Xenopus Proteins / Q000737:chemistry*; D014982:Xenopus laevis
D023181:Antimicrobial Cationic Peptides; D054806:Magainins; D008823:Micelles; D029867:Xenopus Proteins; D010767:Phosphorylcholine; C053301:magainin 2 peptide, Xenopus; C053300:magainin 1 peptide, Xenopus; D012967:Sodium Dodecyl Sulfate; C028810:dodecylphosphocholine