Studies on the Inhibition of Moloney Murine Leukemia Virus Reverse Transcriptase by N-Tritylamino Acids and N-Tritylamino Acid-Nucleotide Compounds

Abstract

N-Acylated derivatives of 8-(6-aminohexyl) amino-adenosine-5 '-phosphate were prepared and studied with regard to their effect on DNA synthesis by the Moloney leukemia virus reverse transcriptase. N-palmitoyl and N-nicotinyl derivatives and bis-8-(6-aminohexyl) amino-5'-AMP inhibited the enzyme partially using poly (rA).oligo d(pT)(16-18) as template-primer with [(3)H]dTTP. In order to increase hydrophobicity in the acyl component tethered to the 8-(6-aminohexyl) amino group on the adenine nucleotide, N-trityl-L-phenylalanine and the N-trityl derivatives of the o, m, and p-fluoro-DL-phenylalanine were initially examined for inhibition of the enzyme using the above template-primer system. The compounds all inhibited the reverse transcriptase with IC(50) values of approximately 60-80 microM. However, when N-trityl-m-fluoro-DL-phenylalanine was coupled to the nucleotide 8-(6-aminohexyl) amino-adenosine-5'-phosphate, the inhibitory activity of this compound increased significantly (IC(50) = 5 microM).

The effect of certain <i>N</i>-tritylated phenylalanine conjugates of amino-adenosine-3’,5’- cyclic monophosphate on moloney murine leukaemia virus reverse transcriptase activity

“…When N-trityl-m-fluoro-DL-phenylalanine was chemically coupled to the 6-amino-side chain of 8-(6-aminohexyl) amino-adenosine-5'-monophosphate, however, the resulting conjugate showed a dramatic increase in inhibitory activity, with an IC 50 value of 5 µM; we have previously discussed possible reasons for this and also suggested how the conjugate might bind to the reverse transcriptase enzyme. 1 In this study, we wished to examine whether the replacement of the adenosine-5'-monophosphate component of N-trityl-m-fluoro-DL-phenylalanine-8- (6-aminohexyl) aminoadenosine-5'-monophosphate with 8-(6-aminohexyl) aminoadenosine-3',5'-cyclic monophosphate would result in a conjugate with an inhibitory effect on the reverse transcriptase enzyme. We therefore synthesised three new conjugates: N-tritylp-fluoro-DL-phenylalanine, N-trityl-p-nitro-DL-phenylalanine and N-trityl-p-iodo-DL-phenylalanine.…”

“…Also, inhibition, when it occurs, should be non-competitive. When using N-tritylm-fluoro-DL-phenylalanine-8-(6-aminohexyl) amino-adenosine-5'-monophosphate in our original paper, 1 we performed competition experiments using varying concentrations of poly rA, d(pT) 16 at fixed concentrations of N-trityl-m-fluoro-DLphenylalanine-nucleotide, which showed the compound acted as a non-competitive inhibitor (results not published).…”

“…In our previous paper, 1 we made the assumption that the nucleotide component (5'-AMP) of the conjugate N-trityl-m-fluoro-DL-phenylalanine-8-(6-aminohexyl) amino-adenosine-5'-monophosphate could possibly bind to the polymerase site (area) of M-MuLV RT, while the N-trityl-m-fluoro-DLphenylalanine grouping was likely to interact with a hydrophobic pocket or area situated 10 Å -15 Å away. The binding of the conjugate therefore resembled the interaction of certain chimeras with HIV-1 RT.…”

“…In a recent article 1 we described the synthesis of a number of N-acylated derivatives of 8-(6-aminohexyl) amino-adenosine-5'-monophosphate. These various acylated derivatives, as well as the free N-trityl substituted DL-phenylalanyl amino acids, were tested for their effect on the DNA polymerase activity of the Moloney murine leukaemia virus reverse transcriptase (M-MuLV RT).…”