| Summary: | 碩士 === 文化大學 === 應用化學系 === 85 === Abstract A sequence of a deoxyribonucleotide that can form a
"paper clip" triple-stranded helix (triplex) unimolecularly was
designed at studied by UV thermal denatured profiles and
circular dichroism spectroscopy (CD) as shown below.
The formation of structure (1) containing pseudoisocytidine and
itsderivatives (at X,Y,Z positions) was investigated as a
function of pH,concentrations of NaCl, MgCl2 in solution as well
as the number ofpseudoisocytidine replaced (at X,Y,Z position).
The results showed thatthe structure (1) can form a stable
triplex at pH 7 when all cytosineshave been replaced by
pseudoisocytidines. The stability of structure (1)is decreased
as the number of replacement of pseudoisocytidine reduced atthe
same pH. However, structure (1) with partial
pseudoisocytidinereplacement can form stable triplexes at
slightly acidic conditions (pH=4.5). In addition, the
thermodynamic parameters (delta (H) ,delta (S) of
theaforementioned triplexes formation were derived from the UV
melting profiles. In conclusion, the detail understanding of
triplex formation containingpseudoisocytidine at physiological
conditions (pH=7) can be applied to thefield of gene therapy.VII
|
|---|
