Stable recognition of TA interruptions by triplex forming oligonucleotides containing a novel nucleoside.
We have prepared the 2'-aminoethoxy derivative of the S nucleoside ((2AE)S) and incorporated it into triplex-forming oligonucleotides for recognition of TA interruptions within a target oligopurine tract. Fluorescence melting, UV melting, and DNase I footprinting experiments show that (2AE)S has greater affinity than G or S for a single TA interruption. Stable triplexes are formed at pH 6.0 at an 18-mer target site containing two TA interruptions, even though this contains eight C(+).GC triplets. Although (2AE)S and S produce stable triplexes at TA interruptions, they also interact with other base pairs, in particular, CG, although the selectivity for TA improves with increased pH.( 2AE)S is the best nucleoside described so far for recognition of TA within a triple-helix target.
Wang
Yang
Y
School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom.
Rusling
David A
DA
Powers
Vicki E C
VE
Lack
Oliver
O
Osborne
Sadie D
SD
Fox
Keith R
KR
Brown
Tom
T
D001483:Base Sequence; D018983:DNA Footprinting; D003850:Deoxyribonuclease I; D003854:Deoxyribonucleotides / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013873:Thionucleotides / Q000737:chemistry
D003854:Deoxyribonucleotides; D009838:Oligodeoxyribonucleotides; D013873:Thionucleotides; D003850:Deoxyribonuclease I