ABSTRACT
Some natural and glycon-modified dNTPs with beta,gamma-pyrophosphate substitution at the triphosphate residue were synthesized and studied to evaluate the effect of these modifications on substrate properties of dNTPs in DNA synthesis catalyzed by human placental DNA polymerases alpha and beta, avian myeloblastosis virus reverse transcriptase, and calf thymus terminal deoxynucleotidyl transferase. Reverse transcriptase proved to be the enzyme least specific to such modifications; the substrate activity of beta,gamma-methylenediphosphonate substituted dTTP and 3'-azido-3'-deoxy-dTTP decreased in the following order: CF2 = CHF > CBr2 > CFMe >> CH2. This order is individual for each DNA polymerase. It is interesting to mention that beta,gamma-CBr2 substituted dTTP is neither a substrate nor an inhibitor of DNA polymerase beta. This specificity distinguishes DNA polymerase beta from other DNA polymerases studied.
Subject(s)
DNA-Directed DNA Polymerase/metabolism , Deoxyribonucleotides/metabolism , Animals , Avian Myeloblastosis Virus/enzymology , Base Sequence , Cattle , DNA Nucleotidylexotransferase/metabolism , DNA Primers , Humans , Molecular Sequence Data , Molecular Structure , Phosphates/metabolism , RNA-Directed DNA Polymerase/metabolism , Structure-Activity Relationship , Substrate SpecificityABSTRACT
Several 5'-fluoroalkylphosphonates of 3'-azido-3'-deoxythymidine and 3'-deoxy-2',3'-didehydrothymidine were synthesized as potential antiviral compounds. Fluoromethyl, difluoromethyl, fluorochloromethyl and vinyl phosphonates were used as phosphonylating components, with dicyclohexylcarbodiimide or triisopropylbenzenesulphonyl chloride as condensing reagents.
