2'-DEOXYNUCLEOSIDE 5'-TRIPHOSPHATES MODIFIED AT ALPHA-PHOSPHATE, BETA-PHOSPHATE AND GAMMA-PHOSPHATE AS SUBSTRATES FOR DNA-POLYMERASES

Replacement of alpha-, beta- and gamma-phosphate groups in 2'-deoxynuc leoside 5'-triphosphates (dNTP) with phosphonate groups yields a new s et of dNTP mimics with potential biological and therapeutic applicatio ns. Here, we describe the synthesis of 15 new dNTPs modified at alpha- , beta- and gamma-phosphates containing, in the case of dUTP, reporter and ligand groups at the C5 position of uracil. It is shown that gamm a-substituted dNTPs were substrates for AMV reverse transcriptase desp ite of the large size of substituent at the gamma-phosphonate. On the other hand, these compounds were poorly utilized by DNA polymerase alp ha. For dUTP analogues substituted at both gamma-phosphonate and C5 of uracil, the substrate affinity was 1-2 orders of magnitude lower than for their counterparts containing substituents either at gamma-phosph onate or C5 position. Meanwhile, C5-substituted methylphosphinyl)methy lphosphonyl]-alpha-phosphate and its 3'-azido-3'-deoxy analog were sub strates for AMV reverse transcriptase, but the substrate activity of t hese analogues was 50-100 times lower as compared with dTTP. HIV rever se transcriptase utilized these compounds 1 order of magnitude less ef ficiently than AMV reverse transcriptase; terminal deoxynucleotidyl tr ansferase did not recognize them aat all.