期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：44
页码：12473-12477
DOI：10.1073/pnas.1610371113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In type-2 diabetes (T2D) and Parkinson’s disease (PD), polypeptide assembly into amyloid fibers plays central roles: in PD, α-synuclein (aS) forms amyloids and in T2D, amylin [islet amyloid polypeptide (IAPP)] forms amyloids. Using a combination of biophysical methods in vitro we have investigated whether aS, IAPP, and unprocessed IAPP, pro-IAPP, polypeptides can cross-react. Whereas IAPP forms amyloids within minutes, aS takes many hours to assemble into amyloids and pro-IAPP aggregates even slower under the same conditions. We discovered that preformed amyloids of pro-IAPP inhibit, whereas IAPP amyloids promote, aS amyloid formation. Amyloids of aS promote pro-IAPP amyloid formation, whereas they inhibit IAPP amyloid formation. In contrast, mixing of IAPP and aS monomers results in coaggregation that is faster than either protein alone; moreover, pro-IAPP can incorporate aS monomers into its amyloid fibers. From this intricate network of cross-reactivity, it is clear that the presence of IAPP can accelerate aS amyloid formation. This observation may explain why T2D patients are susceptible to developing PD.
