標題: | Citrullination and deamidation affect aggregation properties of amyloid -proteins |
作者: | Osaki, Dai Hiramatsu, Hirotsugu 應用化學系 Department of Applied Chemistry |
關鍵字: | Charge;oligomer;pH dependence;salt bridge;secondary structure |
公開日期: | Dec-2016 |
摘要: | Citrullination and deamidation, which are aging-related posttranslational modifications, increase the number of negative charges on amyloid -protein (A) at neutral pH. We investigated the effects of these modifications on the fibrillation properties of A. The Arg5Cit modification of A(1-40) did not affect the fibrillation rate, and brought -sheet structures unlike that in the A(1-40) fibril. The Asn27Asp modification of A(1-40) stopped the fibrillation and induced the formation of aggregates that involved an anti-parallel -sheet. A(1-42) with the Arg5Cit modification showed increased solubility in aqueous media, and its fibril formation became slower than that of A(1-42). The modification did not change the parallel -sheet structure of the fibrils. A(1-42) with the Asn27Asp modification partially formed fibrils that involved the parallel -sheet structure. Using the thioflavin T (ThT) assay, an increased fraction of the soluble oligomer of each A analog was transiently detected during fibrillation. An increase in the number of negative charges at basic pH affected the aggregation properties of A in a manner different from that with the modifications, suggesting that change in properties of the posttanslationally modified residues rather than the number of charges in the peptide was important. |
URI: | http://dx.doi.org/10.1080/13506129.2016.1240076 http://hdl.handle.net/11536/132991 |
ISSN: | 1350-6129 |
DOI: | 10.1080/13506129.2016.1240076 |
期刊: | AMYLOID-JOURNAL OF PROTEIN FOLDING DISORDERS |
Volume: | 23 |
Issue: | 4 |
起始頁: | 234 |
結束頁: | 241 |
Appears in Collections: | Articles |