Poly(2-methyl- and 2-ethylthioadenylic acid) were prepared by polymerization of corresponding diphosphates with Escherichia coli polynucleotide phosphorylase. These polynucleotides have relatively large hypochromicity of 30-35%. Acid titration of these polymers showed abrupt transition at pH 5.34-5.4, which may indicate that the introduction of alkylthio group at 2-position of adenine bases reduced their basicity. Thermal melting of these polymers showed no clear transition points at neutral pH, but in acidic media they have Tm values of 57 and 56 degrees C, somewhat lower than that of poly(A). Upon complex formation with poly(U), these poly(A) analogs showed only one poly(rs2A) . poly(U) type double-strand complexes, similar to that found in the case of poly(m2A) . poly(U).
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http://dx.doi.org/10.1016/0005-2787(79)90115-1 | DOI Listing |
In the present study, effects of various 2- and 2'-substituted polyadenylic acid analogs on eukaryotic, bacterial and viral DNA polymerases were investigated. The polymer containing 2'-deoxy-2'fluoroadenosine, (dAfl)n, showed a concentration dependent stimulation of (rA)n . (dT)12-catalyzed reverse transcriptase reaction from Rauscher Leukemia Virus (RLV).
View Article and Find Full Text PDFSeveral newly synthesized polyadenylic acid [(A)n] analogues, including poly(2-methyladenylic acid) [(m2A)n], poly(2-ethyladenylic acid) [(e2A)n], poly(2-isopropyladenylic acid) [(i-pro2A)n], poly(2-methylthioadenylic acid) [(ms2A)n], poly(2-ethylthioadenylic acid) [(e2A)n], poly(2'-fluoro-2'-deoxyadenylic acid) [(dAfl)n] and poly(2'-azido-2'-deoxyadenylic acid) [(dAz)n] have been evaluated for their effects on the RNA-directed DNA polymerase (reverse transcriptase) activity of Moloney murine leukemia virus; (m2A)n and (e2A)n did not markedly affect reverse transcriptase activity, (dAfl)n served as an efficient template for the reverse transcriptase reaction, and (i-pro2A)n, (ms2A)n, (es2A)n and (dAz)n strongly inhibited reverse transcriptase activity. (dAfl)n also served as an efficient template (Km : 0.025 micron) for the reverse transcriptase of avian myeloblastosis virus.
View Article and Find Full Text PDFPoly(2-methyl- and 2-ethylthioadenylic acid) were prepared by polymerization of corresponding diphosphates with Escherichia coli polynucleotide phosphorylase. These polynucleotides have relatively large hypochromicity of 30-35%. Acid titration of these polymers showed abrupt transition at pH 5.
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