Incorporation of (alpha-P-borano)-2',3'-dideoxycytidine 5'-triphosphate into DNA by drug-resistant MMLV reverse transcriptase and Taq DNA polymerase.

The Rp-stereoisomer of 5'-(alpha-P-borano)triphosphates of 2'-deoxycytidine (Rp-dCTPalphaB) and 2',3'-dideoxycytidine (Rp-ddCTPalphaB) were synthesized. Their steady-state kinetics of incorporation by ddNTP-resistant enzymes, e.g., MMLV reverse transcriptase (RT) and Taq DNA polymerase, were investigated and compared with incorporation of dCTP and ddCTP. The alpha-boranophosphate substitution in ddCTP results in a 28-fold increase in efficiency of incorporation of the Rp-ddCTPalphaB isomer by MMLV RT, yet has minimal effect on the efficiency of incorporation by Taq DNA polymerase.