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Structural and Kinetic Properties of Liver Rhodanese from Coptodon zillii: Implications for Cyanide Detoxification in Gold Mining-Impacted Aquatic Ecosystems

  • 0Institute of Drug Research and Development, S.E Bogoro Center, Afe Babalola University, PMB 5454, Ado-Ekiti 360001, Nigeria.
Toxics +

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September 27, 2025

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September 27, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

This study purified fish liver rhodanese, an enzyme crucial for detoxifying cyanide from gold mining pollution. The enzyme shows high potential for bioremediation in contaminated aquatic ecosystems.

Area Of Science

  • Biochemistry
  • Environmental Science
  • Ecotoxicology

Background

  • Gold extraction processes often utilize cyanide, leading to environmental contamination of water resources.
  • Aquatic organisms in polluted environments may develop biochemical adaptations to cope with toxins.

Purpose Of The Study

  • To characterize the rhodanese enzyme from *Coptodon zillii* liver for its role in cyanide detoxification.
  • To assess the enzyme's potential for bioremediation in mining-impacted aquatic ecosystems.

Main Methods

  • Purification of rhodanese using chromatographic techniques.
  • Enzyme characterization including molecular weight, optimal pH, temperature, and metal ion effects.
  • Kinetic analysis and substrate specificity testing.
  • Molecular docking to elucidate enzyme-substrate interactions.

Main Results

  • Purified rhodanese exhibited specific activity of 5.4 U/mg with a 3.1-fold increase.
  • The native enzyme molecular weight was 36 kDa (dimeric structure).
  • Optimal activity at pH 8.0 and 50 °C; KCl enhanced activity, while other tested metal ions inhibited it.
  • Michaelis-Menten kinetics observed with Km values of 20.0 mM (thiosulfate) and 25.0 mM (cyanide).
  • Strong preference for thiosulfate as a substrate.
  • Molecular docking revealed key hydrogen bonds between the enzyme (Glu159, Gln161, Arg173) and thiosulfate.

Conclusions

  • The characterized rhodanese enzyme possesses significant cyanide detoxification capabilities.
  • Findings contribute to understanding biochemical adaptations in stressed environments.
  • The enzyme shows promise for bioremediation strategies in mining-polluted aquatic ecosystems.

Keywords:

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