Cu-induced assembly of methanobactin-modified gold nanoparticles and its peroxidase mimic activity

IET Nanobiotechnol. 2018 Oct;12(7):915-921. doi: 10.1049/iet-nbt.2018.0069.

Abstract

Methanobactin (Mb) is a small copper-chelating molecule that functions as an agent for copper acquisition, uptake and copper-containing methane monooxygenase catalysis in methane-oxidising bacteria. The UV-visible spectral and fluorescence spectral suggested that Mb/Cu coordination complex as a monomer (Mb-Cu), dimmer (Mb2-Cu) and tetramer (Mb4-Cu) could be obtained at different ratios of Mb to Cu (II). The kinetics of the oxidation of hydroquinone with hydrogen peroxide catalysed by the different Mb/Cu coordination complex were investigated. The results suggested that Mb2-Cu coordination form has highest catalytic capacity. Further, Mb-modified gold nanoparticles (AuNPs) were obtained by ligand exchange and assembled into two- and three-D nanocluster structure by metal-organic coordination as driving force. It has been found that AuNPs increased the catalytic activity of Mb2-Cu on AuNPs. The more significant catalytic activity was exhibited by the nanocluster assembly with multi-catalytic centres. This may be attributed to the multivalent collaborative characteristics of the catalytic active centres in the nanocluster network assembly. The assembly of Mb-modified AuNPs can act as excellent nanoenzyme models for imitating peroxidase.

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Copper / chemistry
  • Copper / metabolism*
  • Gold / chemistry*
  • Hydrogen Peroxide / chemistry
  • Hydrogen Peroxide / metabolism
  • Hydroquinones / analysis
  • Hydroquinones / chemistry
  • Hydroquinones / metabolism
  • Imidazoles* / chemistry
  • Imidazoles* / metabolism
  • Kinetics
  • Metal Nanoparticles / chemistry*
  • Oligopeptides* / chemistry
  • Oligopeptides* / metabolism
  • Oxidation-Reduction
  • Peroxidase / chemistry
  • Peroxidase / metabolism*

Substances

  • Bacterial Proteins
  • Hydroquinones
  • Imidazoles
  • Oligopeptides
  • methanobactin
  • Gold
  • Copper
  • Hydrogen Peroxide
  • Peroxidase
  • hydroquinone