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THE ENZYMES OF PYRIMIDINE BIOSYNTHESIS IN BABESIA BOVIS AND BABESIA BIGEMINA
Author(s) -
Gero Annette M,
O'Sullivan William J,
Wright Ian G,
Mahoney David F
Publication year - 1983
Publication title -
australian journal of experimental biology and medical science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0004-945X
DOI - 10.1038/icb.1983.22
Subject(s) - dihydroorotate dehydrogenase , babesia bovis , pyrimidine metabolism , biochemistry , biology , enzyme , babesia , plasmodium berghei , respiratory chain , dehydrogenase , biosynthesis , virology , malaria , immunology , purine
Summary All six enzymes of de novo pyrimidine biosynthesis leading to the formation of UMP have been demonstrated in whole homogenates from two bovine Babesia species, B. bovis and B. bigemina. The specific activities of the respective enzymes were of the same order of magnitude as observed for the related parasite, Plasmodium berghei. The results indicate that both these parasites have the potential of obtaining their pyrimidine requirements by de novo synthesis. Subcellular fractionation established that dihydroorotate dehydrogenase, the fourth enzyme of the pathway, was of a particulate nature. Mammalian respiratory chain inhibitors and ubiquinone analogues caused inhibition of the Babesia dihydroorotate dehydrogenase. As observed for other eukaryotic systems, the dehydrogenase appears to be linked to a respiratory chain via ubiquinone.