Conformational change of a synthetic amyloid analogue des[Ala21,30]A42 upon binding to octyl glucoside micelles.
The secondary structure of a synthetic amyloid fragment des [Ala21,30]A42 was studied by circular dichroism and Fourier transformed infrared spectroscopy. Measurements were performed in trifluoroethanol/water and octyl beta-D-glucopyranoside solutions. The spectra of the peptide in trifluoroethanol indicate a high percentage of alpha-helical structure. However, in octyl glucoside, at and above the critical micelle concentration, the peptide adopts a beta-sheet conformation. Secondary structure analysis yields a predominant (> 70%) beta-sheet content. Our data suggest that the peptide backbone or polar side groups of des[Ala21,30]A42 interact with the sugar-coated surface of micelles, which promotes an alpha to beta conformational transition.
Laczkó-Hollósi
I
I
Institute of Biophysics, Biological Research Center, Szeged, Hungary.
Hollósi
M
M
Lee
V M
VM
Mantsch
H H
HH
D016229:Amyloid beta-Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D002942:Circular Dichroism; D005960:Glucosides; D008823:Micelles; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D013055:Spectrophotometry, Infrared / Q000379:methods
D016229:Amyloid beta-Peptides; D005960:Glucosides; D008823:Micelles; D010455:Peptides; C018619:octyl-beta-D-glucoside