Aggregation of Abeta(1-42) in the presence of short peptides: conformational studies.
CD and infrared spectroscopic studies were performed on (i) the inhibitory effects of equimolar quantities of LPFFD-OH and LPYFD-NH(2) on the time-dependent aggregation of amyloid beta-protein (Abeta) (1-42) and (ii) the beta-sheet-breaker effects of two-fold molar excess of the pentapeptides on aggregated Abeta(1-42) aged 1 week. The data obtained from the time-dependent studies demonstrated that LPFFD-OH did not significantly influence, whereas LPYFD-NH(2) exerted some inhibitory effect on the aggregation of Abeta(1-42). When added to a solution of Abeta(1-42) aged 1 week, LPFFD-OH accelerated, while LPYFD-NH(2) delayed, but did not prevent further fibrillogenesis. The difference in the effects of these two pentapeptides on the aggregational profile of Abeta(1-42) is probably due to the difference in their conformational preferences: LPFFD-OH adopts a beta-turn and extended structures, while LPYFD-NH(2) adopts a prevailing beta-turn conformation.
Laczkó
Ilona
I
Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary. laczko@nucleus.szbk.u-szeged.hu
Vass
Elemér
E
Soós
Katalin
K
Fülöp
Livia
L
Zarándi
Márta
M
Penke
Botond
B
D016229:Amyloid beta-Peptides / Q000737:chemistry*; D002942:Circular Dichroism; D010446:Peptide Fragments / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D010455:Peptides; C075222:amyloid beta-protein (1-42)