Synthesis and biological activities of a phosphorodithioate analog of 2',5'-oligoadenylate.
To enhance the resistance of 2-5A (pppA2'p5'A2'p5'A) to degradation by exo- and endonucleases, a phosphorodithioate analog was synthesized using a solid-phase phosphite triester approach with N6-benzoyl-5'-O-dimethoxytrityl-3'-O-t-butyldimethylsilyladenosine 2'-[S-(beta-thiobenzoylethyl)-pyrrolidinophosphorothioamidit e]. 5'-Monophosphorylation was accomplished with 2-[2-(4,4'-dimethoxytrityloxy)-ethylsulfonyl]ethyl-(2-cyanoe thyl)-(N,N- diisopropyl)-phosphoramidite. The resulting product, p5'A2'(s2p)- 5'A2'(s2p)5'A, was approximately 10-fold less effective as an activator of purified human recombinant 2-5A-dependent RNase than was 2-5A itself. This loss of activation ability was related directly to the loss of binding ability of the phosphorodiothioate analog. As predicted, p5'A2'(s2p)5'A2' (s2p)5'A was stable to snake venom phosphodiesterase and the nucleolytic activities of both human lymphoblastoid CEM cell extracts and human serum, under conditions that led to facile degradation of parent 2-5A. This nuclease stability permitted the observation of the CEM cell extracts and human serum phosphatase activity which led to 5'-dephosphorylation of p5'A2'(s2p)5'A2'(s2p)5'A.
D000227:Adenine Nucleotides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D000998:Antiviral Agents / Q000737:chemistry* / Q000378:metabolism; D004720:Endonucleases / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005092:Exonucleases / Q000378:metabolism; D006801:Humans; D015394:Molecular Structure; D009843:Oligoribonucleotides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D043264:Phosphodiesterase I; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D000227:Adenine Nucleotides; D000998:Antiviral Agents; D009843:Oligoribonucleotides; D011994:Recombinant Proteins; C023505:2',5'-oligoadenylate; D004720:Endonucleases; D005092:Exonucleases; D012260:Ribonucleases; D010727:Phosphoric Diester Hydrolases; D043264:Phosphodiesterase I; C470790:phosphodiesterase I, snake venom