Regulation of -Sheet Structures within Amyloid-Like 详细信息    查看全文

• 作者：Norihiro Yamada ; Katsuhiko Ariga ; Masanobu Naito ; Kazuhiro Matsubara ; and Emiko Koyama
• 刊名：Journal of the American Chemical Society
• 出版年：1998
• 出版时间：December 2, 1998
• 年：1998
• 卷：120
• 期：47
• 页码：12192 - 12199
• 全文大小：235K
• 年卷期：v.120,no.47(December 2, 1998)
• ISSN：1520-5126

文摘

N-(11-Trimethylammonioundecanoyl)-O,O'-didodecyl tripeptide bromides and N-(11-trimethylammonioundecanyl)-O-dodecyl tripeptide bromides formed a parallel -sheet structure when they aggregated inwater and in CCl₄. The parallel -sheet was distinguished from the antiparallel counterpart by Fourier transforminfrared spectroscopy because the former lacks a weak band at about 1690 cm^-1 that is characteristic for thelatter. The FT-IR spectra of the aggregate in CCl₄ remained unchanged if the solution was diluted to 0.01mM, condensed to dryness, or heated to 60 C, and hence, the -sheet was easily formed and thermodynamicallystable. The parallel -sheet was also possible to transform into an antiparallel -sheet, for example, by mixingwith another tripeptide-containing amphiphile whose tripeptide part had an opposite direction. Transmissionelectron microscope (TEM) and atomic force microscope (AFM) pictures revealed that the aggregate in CCl₄is a bundle of small filaments whose diameters are 70-80 Å. Developed interpeptide hydrogen bondingshould be formed along the long axis of the filament. The morphological structures and stable peptidearrangements of the present assemblages are similar to those of the amyloid fiber whose accumulation causesfatal diseases.