Physicochemical Properties of Liver Arginase from Heterotis niloticus (Cuvier 1829)

Authors

  • Okonji Raphael Emuebie Department of Biochemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
  • Ehigie Ona Leonard Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
  • Popoola Michael Olaoluwa Department of Zoology, Obafemi Awolowo University, Ile-Ife, Nigeria.
  • Ehigie Adeola Folashade Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
  • Komolafe Olaniyi Olusola Department of Zoology, Obafemi Awolowo University, Ile-Ife, Nigeria.

Keywords:

Heterotis niloticus, freshwater habitat, arginase, ureotelism, uricotelism

Abstract

We investigated the activity of arginase in the liver of Heterotis niloticus. The enzyme was partially purified and characterized. The native molecular weight was estimated to be 178,000 dalton with Biogel P-200. The enzyme acted on not only L-arginine, but also L-arginine monohydrochloride and L-arginine monohydrate with preference for L-arginine. The enzyme had a specific activity of 6.18 µmol/min/mg of protein. The enzyme exhibited a maximal activity at pH 5.5 and KM of 11.6 mM. The optimum temperature was found to be 350C. The enzyme showed increased activated with Mn2+, Zn2+, Mg2+, Hg2+, Co2+, and Na+ while the other metals Sn2+, Ni2+ and Ba2+ showed slight inhibition. The order of effectiveness of amino acids as inhibitors of enzyme was found to be proline> lysine>cysteine>valine>serine>aspartate with 56%, 46%, 42%, 42%, 42% and 30% inhibition, respectively. 

Downloads

Published

2021-07-10

Issue

Vol. 13 No. 1 (2014): Journal of Science Research

Section

Articles