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波段试验 具有5‘-GGT GCG Acc TCG QAT CGT GCT CCT CAT CCT CGT的50聚体双工 GTC CTA ATC TAT CGT AT与其补体(2-氨基嘌呤)匹配 与自旋标签q)匹配。旋转标签在位置13。 在1997年度的拨款年度内，我们取得了一套广泛的 自旋标记DNA片段的实验95 GHz EPR谱 不同的长度。对这些光谱的分析表明，增强的 W波段EPR的G因子分辨率允许表征 段内运动不仅沿z方向，而且沿x-和 Y方向。此信息在较早的X波段中不可用 学习。数据还显示出对这些参数的敏感度大大提高 并将导致对刚性的更好的理解 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.