Induced conformational states of amphipathic peptides in aqueous/lipid environments.
Specific conformational effects have been reported for amphipathic model peptides upon binding of defined hydrophobic domains to nonpolar stationary phases during reversed-phase high performance liquid chromatography (RP-HPLC). Such induced conformations are found to be especially pronounced for peptides that are amphipathic in an alpha-helical conformation. Such induced amphipathic conformations resulted in substantially later elution than predicted using amino acid-based retention coefficients. In the present study, the induced conformational behavior of model peptides observed during RP-HPLC was correlated with their secondary structure as determined by circular dichroism (CD) spectroscopy in both aqueous solution and C18-mimetic environments. The experimental retention times of the peptides studied were found to correlate with their CD spectra in the presence of lipids, whereas a poor correlation was observed with their CD spectra in the presence of trifluoroethanol. A new approach was developed to evaluate the induction of secondary structure in peptides due to interactions at aqueous/lipid interfaces, which involves the measurement of the CD ellipticities of peptides bound to a set of C18-coated quartz plates. An excellent correlation was found in this environment between the RP-HPLC retention times and CD ellipticities of the bound peptides.
Blondelle
S E
SE
Torrey Pines Institute for Molecular Studies, San Diego, California 92121.
Ostresh
J M
JM
Houghten
R A
RA
Pérez-Payá
E
E
D000595:Amino Acid Sequence; D055592:Biophysical Phenomena; D001703:Biophysics; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D015195:Drug Design; D008055:Lipids; D008555:Melitten / Q000737:chemistry; D008956:Models, Chemical; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012996:Solutions; D014364:Tryptophan / Q000737:chemistry; D014867:Water
D008055:Lipids; D010455:Peptides; D012996:Solutions; D014867:Water; D008555:Melitten; D014364:Tryptophan