Chinese Journal of Applied Chemistry ›› 2018, Vol. 35 ›› Issue (2): 147-153.DOI: 10.11944/j.issn.1000-0518.2018.02.170378

• Full Papers • Previous Articles     Next Articles

Effect of Copper Ions on the Aggregation of Human Islet Amyloid Polypeptide(1128)

LU Chenga,LI Lina,YAN Penga,ZHANG Nana,CHEN Wuchaoa,ZHANG Gongjunb,ZHOU Xingfeia*()   

  1. aSchool of Science,Ningbo University,Ningbo,Zhejiang 315211,China
    bNingbo Institute of Material Technology and Engineering,Chinese Academy of Sciences,Ningbo,Zhejiang 315201,China
  • Received:2017-10-23 Accepted:2017-12-18 Online:2018-02-01 Published:2018-01-29
  • Contact: ZHOU Xingfei
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.11474173 ), the Zhejiang Provincial Natural Science Foundation(No.LY18A040003).

Abstract:

Human islet amyloid polypeptide(hIAPP) is closely associated with type 2 diabetes mellitus(T2DM), which is one of possible pathogenic factors of islet beta cell apoptosis. It has been suggested that the environmental factors(such as metal ions, pH and temperature) have great effects on the aggregation process of hIAPP. In this study, we investigate the influence of copper(Ⅱ) ions on the aggregation of hIAPP and its fragments by a variety of biophysical methods. Atomic force microscope(AFM) and thioflavin T(ThT) fluorescence measurements show that the copper ions can inhibit hIAPP(137) and hIAPP(1128) to aggregate into fibers. In addition, the micro-Fourier transform infrared spectroscopy(Micro-FTIR) shows that copper ions can restrain the transition from alpha helices structure to beta sheets formation during the peptide incubation. By the single amino acid mutation experiment, we speculate that the His18 in hIAPP(1128) may have a dominant effect on the aggregation behavior and the interaction with copper ions.

Key words: copper(Ⅱ) ions, human islet amyloid protein, type 2 diabetes