T. Arima, H. Akiyoshi, S. Fujii
Jun 1, 1977
Citations
1
Influential Citations
14
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Quality indicators
Journal
Cancer research
Abstract
A magnesium-independent deoxyuridine-5'-triphosphatase was found in Yoshida sarcoma cells but not in normal rat liver. The phosphatase is specific for deoxyuridine 5'-diphosphate and deoxyuridine triphosphate, and its Km for deoxyuridine triphosphate is 2.7 X 10(-7) M. The enzyme was not inhibited by fluoride and required no divalent cations. Thus it differs from known nucleotide phosphatases. Deoxyuridine monophosphokinase, which is detectable in a crude extract of normal rat liver, could not be detected in an extract of Yoshida sarcoma cells. However, with hydroxylapatite column chromatography of the extract, a deoxyuridine 5'-monophosphate kinase activity as high as that in normal rat liver was found in fractions separated from the phosphatase activity. Thus the absence of detectable deoxyuridine 5'-monophosphate kinase activity in the crude extract of Yoshida sarcoma cells is due to the presence of this nucleotide phosphatase.