Mechanism of DNA triplex formation and its specificity as studied by filter binding assay.
The filter binding method was found to be a very useful method for triple-helical formation of oligo DNA duplexes with homoprymidine single-strands. Using this method, we have obtained dissociation constants of triplexes and association rates of triple-helical formation of a variety of combinations of double-strands (23-mer) and pyrimidine single-strands as functions of pH and temperature. pH dependences of dissociation constants and association rates are theoretically discussed in terms of acid-base equilibrium of pyrimidine strands. Temperature-dependence of dissociation constants and association rates were considerably different between acidic and neutral pH range, suggesting that mechanism of triple-helical formation differs between two pH ranges. The results were best interpreted in terms of a three-state model for the triple-helical formation. Furthermore, the effect of mismatched sequences on the stability of the triplexes were also discussed.
Shindo
H
H
Tokyo College of Pharmacy, Japan.
Kamiya
M
M
Torigoe
H
H
Sarai
A
A
D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D005374:Filtration; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D013696:Temperature
D004247:DNA