National Natural Science Foundation of China (NSFC)
2017YFA0504700
中国
National Natural Science Foundation of China (NSFC)
2018YFE0203300
中国
National Natural Science Foundation of China (NSFC)
2021YFA1300100
中国
引用
ジャーナル: iScience / 年: 2022 タイトル: A new polymorphism of human amylin fibrils with similar protofilaments and a conserved core. 著者: Dongyu Li / Xueli Zhang / Youwang Wang / Haonan Zhang / Kai Song / Keyan Bao / Ping Zhu / 要旨: Pancreatic amyloid deposits composed of a fibrillar form of the human islet amyloid polypeptide (hIAPP) are the pathological hallmark of type 2 diabetes (T2D). Although various cryo-EM structures of ...Pancreatic amyloid deposits composed of a fibrillar form of the human islet amyloid polypeptide (hIAPP) are the pathological hallmark of type 2 diabetes (T2D). Although various cryo-EM structures of polymorphic hIAPP fibrils were reported, the underlying polymorphic mechanism of hIAPP remains elusive. Meanwhile, the structure of hIAPP fibrils with all residues visible in the fibril core is not available. Here, we report the full-length structures of two different polymorphs of hIAPP fibrils, namely slim form (SF, dimer) and thick form (TF, tetramer), formed in a salt-free environment, which share a similar ζ-shaped protofilament but differ in inter-protofilament interfaces. In the absence of salt, electrostatic interactions were found to play a dominant role in stabilizing the fibril structure, suggesting an antagonistic effect between electrostatic and hydrophobic interactions in different salt concentrations environments. Our results shed light on understanding the mechanism of amyloid fibril polymorphism.