Thioflavin T-Silent Denaturation Intermediates Support the Main-Chain-Dominated Architecture of Amyloid Fibrils

详细信息    查看全文

• 作者：Sayaka Noda ; Masatomo So ; Masayuki Adachi ; József Kardos ; Yoko Akazawa-Ogawa ; Yoshihisa Hagihara ; Yuji Goto
• 刊名：Biochemistry
• 出版年：2016
• 出版时间：July 19, 2016
• 年：2016
• 卷：55
• 期：28
• 页码：3937-3948
• 全文大小：749K
• 年卷期：0
• ISSN：1520-4995

文摘

Ultrasonication is considered one of the most effective agitations for inducing the spontaneous formation of amyloid fibrils. When we induced the ultrasonication-dependent fibrillation of β₂-microglobulin and insulin monitored by amyloid-specific thioflavin T (ThT) fluorescence, both proteins showed a significant decrease in ThT fluorescence after the burst-phase increase. The decrease in ThT fluorescence was accelerated when the ultrasonic power was stronger, suggesting that this decrease was caused by the partial denaturation of preformed fibrils. The possible intermediates of denaturation retained amyloid-like morphologies, secondary structures, and seeding potentials. Similar denaturation intermediates were also observed when fibrils were denatured by guanidine hydrochloride or sodium dodecyl sulfate. The presence of these denaturation intermediates is consistent with the main-chain-dominated architecture of amyloid fibrils. Moreover, in the three types of denaturation experiments conducted, insulin fibrils were more stable than β₂-microglobulin fibrils, suggesting that the relative stability of various fibrils is independent of the method of denaturation.