Interaction of the 5'-phosphates of the anti-HIV agents, 3'-azido-3'-deoxythymidine and 3'-azido-2',3'-dideoxyuridine, with thymidylate synthase.
A study has been made of the interaction of 3'-azido-3'-deoxythymidine 5'-phosphate (AZTMP) and 3'-azido-2',3'-dideoxy-uridine 5'-phosphate (AZdUMP) with thymidylate synthase. With the enzyme from L1210 cells and the tapeworm Hymenolepis diminuta, AZTMP was a weak inhibitor competitive with respect to dUMP (Ki = 6.3 mM and 0.5 mM); hence cytotoxicity of AZT, in cells in which accumulation of AZTMP is not high, is not due to inhibition of cellular thymidylate synthase. AZdUMP, with the L1210 enzyme, was a weak substrate (competition with dUMP described by apparent Ki = 4.7 mM), excluding conversion of AZdUMP to AZTMP as a source of toxicity of 3'-azido-2',3'-dideoxyuridine. An efficient procedure is described for enzymatic phosphorylation on a preparative scale of dideoxynucleosides.
Dzik
J M
JM
Nencki Institute of Experimental Biology, Academy of Sciences, Warszawa, Poland.
Bretner
M
M
Kulikowski
T
T
Ciesla
J
J
Ciesla
J M
JM
Rode
W
W
Shugar
D
D
D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism*; D054306:Dideoxynucleotides; D006926:Hymenolepis / Q000201:enzymology; D007939:Leukemia L1210 / Q000201:enzymology; D013940:Thymidylate Synthase / Q000378:metabolism*; D013942:Thymine Nucleotides; D015215:Zidovudine / Q000031:analogs & derivatives* / Q000378:metabolism
D000998:Antiviral Agents; D054306:Dideoxynucleotides; D013942:Thymine Nucleotides; C057288:3'-azido-2',3'-dideoxyuridine 5'-monophosphate; C057287:3'-azido-3'-deoxythymidine 5'phosphate; D015215:Zidovudine; D013940:Thymidylate Synthase