| Summary: | 碩士 === 中國文化大學 === 應用化學研究所 === 87 === Oligonucleotide triple-stranded helix formation is one of the most versatile methods for the sequence-specific recognition of double helical DNA. The specificity is derived from the formation of hydrogen bonds between bases in the third strand and duplex base pairs. There are currently two classes of base triads, namely Py‧PuPy and Pu‧PuPy. Both sequence-specific recognition of dsDNA appears to be limited mostly to purine tracts. Design leads to expand the recognition code to pyrimidine-purine base pair(CG and AT). This would provide one step toward a general solution for targeting single sites in megabase size DNA.
In this report, N4-(6-aminopyridin-2-yl)-2'-deoxycytidine (PC) with a sequence has been used for interaction with C‧G base pair through hydrogen bonds. The triplex containing PC‧C‧G triad was investigated as a function of pH, concentrations of NaCl, MgCl2, Spermine in solution as well as the number of pC‧C‧G triad replaced in the different site spectroscopically. The results showed that the pC can formed a stable triplex with sequence(TMCTCTMC-TT-CTGTCT-CC-AGA PC AG) at pH7. However, it can form stable triplexes at slightly acidic condition (pH4.5). In conclusion, the detail understanding of triplex formation containing PC at physiological conditions can be applied to the field of gene therapy.
|
|---|
