目前已有不少研究使用固態核磁共振儀﹐來作對DNA的內部動力學探
討﹐並且發展了不少圖形的模擬分析技術。由於可利用氘的取代步驟﹐將
purine上的C8位置或在pyrimidine上的C6位置以氘取代之﹔使用簡單的四
極矩回波技術﹐觀測該取代的氘在強磁場中產生的四極矩分裂效應。
本實驗所使用的樣品﹐主要有兩項:一為d(GAGAGAGA)與d(TCTCTCTC)的單
股﹑雙股﹑三股配對﹔另一為來自中央研究院甘魯生博士的d(AGAGAG)與
d(TCTCTCTTTTTCTCTCT)的單股﹑三股配對。將這些DNA按照固定的比例﹐
配成不同的雙股或三股﹐放置在不同的相對濕度下﹐作氘的固態核磁共振
光譜。經由計算及電腦的圖譜模擬﹐而得到自旋-自旋緩解時間(T1)﹑自
旋-晶格緩解時間(T2e)﹑相關緩解時間(tc)等數值。並由此進一步模擬
DNA的鹼基在各種狀況下的運動模式﹐及分子整體運動在緩解時間上有何
影響。 我們希望透過如此的動力學分析﹐將分子的所有運動模式找出
﹔若能早日了解DNA的分子行為﹐則可預測其在細胞分裂中扮演的角色及
功能。

We are utilized solid-state deuterium NMR spectroscopy to
reveal the dynamic nature of DNA structure. Two model system
were investigated. The first triplex model system, namely d(GA)4
.2d(TC)4, which consists of d(GAGAGAGA) and d(TCTCTCTC). This
model system permit us to study single-stranded, double-stranded
as well as triple-stranded DNA in sequence. Whereas, the other
triplex model system, namely d(AG)3.d(CC), which consists of d(
AGAGAG) and a folded d(TCTCTCTTTTCTCTCT). This model system
allow us to study only single-stranded and triple-stranded DNA.
For both triplex model compounds, all purine C8H of the central
strand were exchanged by deuteron. We have some interesting
conclusion: a. In dry DNA, The spin-lattice relaxation time(T1)
was much smaller than dry Adenine and Guanine and didn't affect
by single-stranded﹑double-stranded and triple-stranded
conformations. b. At 80% humidity, T1 and T2e decreased greatly,
and the central position of the spectroscopy was lower than 0%.
This may be caused by the rotation or bending about helix axis.
c. At 98% humidity, the T2e of single-stranded and double-
stranded DNA were higher than 80% and 90% humidity, this implied
that the motion observed at 80% humidity was speeded up from μ
sec to nsec when the humidity increased. We assumed this motion
must be global motion. d. T2e of triple-stranded DNA
increasedabove 90% humidity, indicated that the global motion
was affected easily by structure.
We are utilized solid-state deuterium NMR spectroscopy to