title: Inhibition of amyloid peptide fibril formation by gold-sulfur complexes.
abstract: Amyloid-related diseases are characterized by protein conformational change and amyloid fibril deposition. Metal complexes are potential inhibitors of amyloidosis. Nitrogen-coordinated gold complexes have been used to disaggregate prion neuropeptide (PrP106-126) and human islet amyloid polypeptide (hIAPP). However, the roles of metal complexes in peptide fibril formation and related bioactivity require further exploration. In this work, we investigated the interactions of amyloid peptides PrP106-126 and hIAPP with two tetracoordinated gold-sulfur complexes, namely, dichloro diethyl dithiocarbamate gold complex and dichloro pyrrolidine dithiocarbamate gold complex. We also determined the effects of these complexes on peptide-induced cytotoxicity. Thioflavin T assay, morphological characterization, and particle size analysis indicated that the two gold-sulfur complexes effectively inhibited the fibrillation of the amyloid peptides, which led to the formation of nanoscale particles. The complexes reduced the cytotoxicity induced by the amyloid peptides. Intrinsic fluorescence, nuclear magnetic resonance, and mass spectrometry revealed that the complexes interacted with PrP106-126 and hIAPP via metal coordination and hydrophobic interaction, which improved the inhibition and binding of the two gold-sulfur compounds. Our study provided new insights into the use of tetracoordinated gold-sulfur complexes as drug candidates against protein conformational disorders.
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, PR China.
authors.forename: Wenji
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, PR China.
authors.forename: Cong
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, PR China.
authors.forename: Dengsen
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, PR China.
authors.forename: Gehui
authors.initials: G
authors.lastname: Gong
authors.affiliation: Department of Chemistry, Renmin University of China, Beijing 100872, PR China. Electronic address: whdu@ruc.edu.cn.
authors.forename: Weihong
authors.initials: W
authors.lastname: Du
mesh_terms: D056831:Coordination Complexes / Q000737:chemistry / Q000494:pharmacology*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D058228:Islet Amyloid Polypeptide / Q000096:biosynthesis*; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D011487:Protein Conformation / Q000187:drug effects; D013455:Sulfur / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D058228:Islet Amyloid Polypeptide; D013455:Sulfur; D006046:Gold
keywords: Aggregation; Amyloid peptides; Gold-sulfur complex; Inhibition; Interaction