HF (95 GHZ) EPR OF SPIN LABELED DNA

我们正在探索高频电子顺磁共振在分子研究中的应用 自旋标记DNA的运动 初步试验包括W波段实验 用5 '-GGT GCG ACC TCG QAT CGT GCT CCT CAT CCT CGT的50-mer双链体 GTC CTA ATC达特CGT AT与其补体（2-氨基嘌呤）匹配 与自旋标记Q匹配）。 自旋标签位于位置13。 在1997年赠款年度，我们获得了一套广泛的 实验95-GHz EPR光谱从自旋标记的DNA片段的 不同的长度。 对这些光谱的分析表明， W波段EPR的g因子分辨率允许对 片段内运动不仅沿沿着z方向，而且沿沿着x方向， y方向。 这些信息是从早期的X波段无法获得的 问题研究 数据还显示了对这些的极大灵敏度增强 运动模式，并将导致更好地了解刚性的 DNA.

We are exploring applications of HF EPR in studying molecular motion of spin-labeled DNA. Initial trials include W-band experiments with a 50-mer duplex of 5'-GGT GCG ACC TCG QAT CGT GCT CCT CAT CCT CGT GTC CTA ATC TAT CGT AT matched against its complement (2-aminopurine matches against the spin label Q). The spin label is in position 13. During the 1997 grant year we have acquired an extensive set of experimental 95-GHz EPR spectra from spin-labeled DNA segments of different length. Analysis of these spectra indicate that enhanced g-factor resolution of W-band EPR allows to characterise the intrasegment motion not only along the z-direction, but along x- and y-directions. This information was not available from earlier X-band studies. The data also show a great sensitivity enhancement to these modes of motion and will lead to a better understanding of rigidity of DNA.