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In Schistosoma mansoni, the major product of in vitro orotate metabolism was orotidine 5'-monophosphate (OMP), whereas in mouse liver it was UMP. In contrast to mammalian cells, OMP appeared not to be 'channeled' from orotate phosphoribosyltransferase to OMP decarboxylase in S. mansoni, resulting in substantial degradation of OMP to orotidine. Significant differences were observed in the inhibitor specificity of phosphoribosyltransferase between S. mansoni and mouse liver, indicating that this enzyme may be a potential chemotherapeutic target in S. mansoni. Two distinct phosphoribosyltransferases were found in S. mansoni. One enzyme, having the higher molecular weight, utilized orotate, 5-fluorouracil and uracil as substrates, while the other only orotate. Both enzymes were inhibited by 5-azaorotic acid (oxonic acid) but only the 'orotate-specific' enzyme was inhibited by 4,6-dihydroxypyrimidine. OMP decarboxylase activity co-eluted with both phosphoribosyltransferases from Sephadex G-100 gel chromatography. We suggest that phosphoribosyltransferase in S. mansoni plays a role in both de novo UMP biosynthesis as well as in the salvage of uracil and uridine.
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
February 1987,
International journal for parasitology,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
January 1974,
Advances in enzyme regulation,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
April 1980,
Annals of tropical medicine and parasitology,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
August 1991,
FEMS microbiology letters,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
January 1982,
Acta Leidensia,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
January 1973,
Transactions of the Royal Society of Tropical Medicine and Hygiene,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
October 1993,
Molecular and biochemical parasitology,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
July 1970,
Biochimica et biophysica acta,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
January 1957,
Biochimica et biophysica acta,
M H Iltzsch, and
J G Niedzwicki, and
A W Senft, and
S Cha, and
M H El Kouni
August 1973,
The Journal of biological chemistry,
