Andrey A. Arzumanov

Gamma-phosphate-substituted 2'-deoxynucleoside 5'-triphosphates as substrates for DNA polymerases.

Several 2′-deoxythymidine 5′-triphosphate and 3′-azido-2′,3′-dideoxythymidine 5′-triphosphate analogs containing a hydrophobic phosphonate group instead of the γ-phosphate were synthesized and evaluated as substrates for human immunodeficiency virus (HIV) and avian myeloblastosis virus reverse transcriptases, human placental DNA polymerases α and β, and calf thymus terminal deoxynucleotidyl transferase. They were efficiently incorporated into the DNA chain by the retroviral enzymes but were not utilized by the mammalian ones. Also, some γ-ester and γ-amide derivatives of dTTP and 3′-azido-2′,3′-dideoxythymidine 5′-triphosphate (AZTTP) were synthesized and studied. They proved to be substrates for both the retroviral and mammalian enzymes under study. The Km values for incorporation of the dTTP derivatives into the DNA chain were close to those for dTTP and AZTTP. The Km for the AZTTP derivatives were one order of magnitude greater than those for dTTP and AZTTP. The results obtained indicate that HIV and avian myeloblastosis virus reverse transcriptases have no sterical obstacles for binding the triphosphate fragment bearing a bulky substituent at the γ-position. Modification of the γ-phosphate in AZTTP increased the selectivity of HIV reverse transcriptase inhibition versus DNA polymerase α. γ-Methylphosphonate and γ-phenylphosphonate were dephosphorylated in human serum much less rapidly than AZTTP. Besides, they were shown to be markedly more hydrophobic than AZTTP. Thus, replacement of the γ-phosphate in AZTTP with γ-phosphonate markedly alters its substrate properties toward some cellular DNA polymerases and blood dephosphorylating enzymes but does not change its substrate activity with respect to HIV reverse transcriptase.

Synthesis of non-nucleoside triphosphate analogues, a new type of substrates for terminal deoxynucleotidyl transferase.

Abstract A series of non-nucleoside triphosphate analogues were synthesized. In place of the nucleoside fragment, substituents bearing aromatic groups were introduced; the triphosphate component was replaced at α, β, or γ-positions by phosphonates. α-[2-N-(9-Fluorenylmethoxycarbonyl)aminoethylphosphonyl]-β,γ-difluoromethylenediphosphonate (IIc) revealed the best substrate properties toward terminal deoxynucleotidyl transferase.

Human DNA polymerases and retroviral reverse transcriptases: selectivity in respect to dNTPs modified at triphosphate residues.

Abstract A series of dTTP and ddTTP(3′N3) γ-phosphonates and β,γ-diphosphonates are studied as substrates or terminating substrates towards different human DNA polymerases and retroviral reverse transcriptases.

Synthesis and Substrate Properties of Thymidine 5′-Triphosphate Analogs with Large Hydrophobic Substituent Groups At α-P Atom

Abstract The new thymidine 5′-O-triphosphate analogs—thymidine 5′-O-α-phenylphosphonyl-β, γ-diphosphate 4, 3′-fluoro-3′-deoxythymidine 5′-O-α-phenylphosphonyl-β, γ-diphosphate 5 and thymidine 5′-O-α-decylphosphonyl-β, γ-diphosphate 6 were synthesized. Their substrate properties towards avian myeloblastosis virus and human immunodeficience virus reverse transcriptases, DNA polymerase β from rat liver and terminal deoxynucleotidyltransferase from calf thymus were demonstrated. The mixture of Rp and Sp diastereomers of 4 was separated by reversed phase HPLC, diastereomeric selectivity of the reaction of DNA chain elongation was noted.

Phosphate-Modified Nucleotides: Conversions in Human Serum

Abstract Mechanisms and rates of hydrolytic dephosphorylation of 5′-hydrogenphosphonates, 5′-phosphorofluoridates, and 5′-phosphates of natural and 3′-substituted thymidines in human serum were studied. The stability of 5′-phosphonates of 2′-deoxy- and 2′,3′-dideoxyadenosines in calf and human sera was found.

Synthesis of 5′-H-Phosphonates of 3′-Substituted Purine Deoxynucleosides

Abstract H-Phosphonates of 3′-azido-2′,3′-dideoxy-adenosine, 3′-azido-2′,3′-dideoxyguanosine and 3′-chloro-2′,3′-dideoxyadenosine were synthesized and their antiviral activity in HIV-infected cell cultures was investigated.