African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12168

Full Length Research Paper

Physicochemical properties of rhodanese from the kidney of cane rat (Thryonomys swinderianus)

Leonard Ona Ehigie
  • Leonard Ona Ehigie
  • Department of Biochemistry, Faculty of Basic Medical Science, Ladoke Akintola University Technology, Ogbomoso, Nigeria.
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Bamidele Sanya Fagbohunka
  • Bamidele Sanya Fagbohunka
  • Department of Biochemistry, Faculty of Basic Medical Science, Olabisi Onabanjo University, Remo Campus, Ikenne, Ogun State, Nigeria.
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Babamotemi Oluwasola Itakorode
  • Babamotemi Oluwasola Itakorode
  • Department of Chemical Sciences, College of Natural and Applied Sciences, Oduduwa University Ipetumodu, Ile-Ife, Nigeria.
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Raphael Emuebie Okonji
  • Raphael Emuebie Okonji
  • Department of Biochemistry and Molecular Biology, Faculty of Science, Obafemi Awolowo University, Ile-Ife, Nigeria.
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  •  Received: 13 April 2019
  •  Accepted: 31 May 2019
  •  Published: 12 June 2019

Abstract

We report the properties of partially purified rhodanese, a cyanide detoxifying enzyme isolated from the kidney of the greater cane rat commonly known as grasscutter (Thryonomys swinderianus). T. swinderianus kidney rhodanese had a specific activity of 1.43 µmole/min/mg protein, a fold of 2.31 and a 55% recovery. The apparent Km values of 0.408 and 0.316 mM were obtained for both sodium thiosulphate (Na2S2O3) and potassium cyanide (KCN) respectively. Substrate specificity study showed that T. swinderianus rhodanese can use other substrates. The enzyme showed its maximum activity at pH 8.0 and 50°C. The assay for the effect of metal ions showed that the enzyme is not affected or inhibited by metal ions such as Na+, Fe3+ but inhibited by Hg2+. The continued existence of T. swinderianus after consumption of food crops with high cyanogenic glycosides suggests that the animal has a functional cyanide detoxification mechanism.

 

Keywords: Rhodanese, cyanide, kinetics, detoxification, cane rat, grasscutter.