Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The reverse transcriptase (RT) of HIV which has been inhibited by the incorporation of AZT into the primer strand is subject to a deblocking reaction by cellular ATP. This reaction yields unblocked primer plus the dinucleoside tetraphosphate, AZTp(4)A. In the present study, we report that AZTp(4)A is an excellent substrate for the enzyme Ap(4)A hydrolase (asymmetrical dinucleoside tetraphosphatase, EC 3.6.1.17), an enzyme that is widely distributed in many cell types. Progress of the reaction has been monitored by 31P NMR, and it was found that hydrolysis results in the production of AZTTP:ATP in a 7:1 ratio. The AZTp(4)A was also hydrolyzed at a rate 1.8-fold more rapidly than Ap(4)A. Spectrophotometric assays yielded Michaelis constants of 2.35 and 0.71 microM for Ap(4)A and AZTp(4)A, respectively. It, therefore, appears that Ap(4)A hydrolase can play a useful role in the regeneration of the AZTTP, the active form of AZT, for the inhibition of HIV RT.
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PMID:Metabolic transformation of AZTp4A by Ap4A hydrolase regenerates AZT triphosphate. 1276 70