Dihydroorotase of human malarial parasite Plasmodium falciparum differs from host enzyme

Biochem Biophys Res Commun. 2008 Feb 15;366(3):821-6. doi: 10.1016/j.bbrc.2007.12.025. Epub 2007 Dec 17.

Abstract

Plasmodium falciparum, the causative agent of human malaria, is totally dependent on de novo pyrimidine biosynthetic pathway. A gene encoding P. falciparum dihydroorotase (pfDHOase) was cloned and expressed in Escherichia coli as monofunctional enzyme. PfDHOase revealed a molecular mass of 42kDa. In gel filtration chromatography, the major enzyme activity eluted at 40kDa, indicating that it functions in a monomeric form. This was similarly observed using the native enzyme purified from P. falciparum. Interestingly, kinetic parameters of the enzyme and inhibitory effect by orotate and its 5-substituted derivatives parallel that found in mammalian type I DHOase. Thus, the malarial enzyme shares characteristics of both type I and type II DHOases. This study provides the monofunctional property of the parasite DHOase lending further insights into its differences from the human enzyme which forms part of a multifunctional protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Dihydroorotase / chemistry*
  • Enzyme Activation
  • Enzyme Stability
  • Humans
  • Molecular Sequence Data
  • Plasmodium falciparum / enzymology*
  • Substrate Specificity

Substances

  • Dihydroorotase