Huang Y, Xia N, Chen M, Yang P, Liu L, Wang J. A copper complex formed with neurokinin B: binding stoichiometry, redox properties, self-assembly and cytotoxicity.
Metallomics 2020;
12:1802-1810. [PMID:
33084705 DOI:
10.1039/d0mt00143k]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The tachykinin neuropeptide of neurokinin B (NKB) is a copper-binding amyloid peptide with important roles in the regulation of physiological functions and pathophysiological processes in the central and peripheral nervous systems. In this work, the formation of a NKB-Cu2+ complex in a 1 : 1 stoichiometry was confirmed by mass spectrometry. The self-assembly of NKB and its mutant species was investigated by Thioflavin T (ThT) fluorescence assay and atomic force microscopy (AFM), and at the same time, the effect of Cu2+ on the aggregation of NKB was studied. As evidenced by cyclic voltammetry, the redox potential of NKB-Cu2+ was determined to be 0.77 V (vs. Ag/AgCl). It has been demonstrated that NKB at low concentrations exerts its neuroprotective function by inhibiting Cu2+-mediated reactive oxygen species (ROS) production in the presence of ascorbic acid (AA). In comparison with equivalent Cu2+, the peptide-Cu2+ aggregates aggravated the viability of PC-12 cells more seriously in the absence of AA. These results should be extremely valuable for understanding the NKB/Cu2+ interactions and the toxicity mechanism of Cu2+ associated with neurodegenerative diseases.
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