Maximum-likelihood approach to single-molecule polarization modulation analysis.
Maximum-likelihood approach to single-molecule polarization modulation analysis.
复制标题
单分子偏振调制分析的最大似然方法。
DOI：
10.1002/cphc.200300677
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Johnson,CareyK
中科院分区：
文献类型：
--
作者：
Osborn,KennethD;Singh,ManojK;Urbauer,RamonaJBieber;Johnson,CareyK
单分子光谱学越来越多地用于探测单个分子的动力学[1]，对单分子运动敏感的光谱技术对于检测这些过程非常重要。有几种单分子方法能够真实的跟踪分子运动。可以分析单个分子的双折射强度轨迹来表征潜在的动力学。[2]荧光共振能量转移，监测两个荧光团之间的距离变化，[3±5]可以跟踪蛋白质上两个染料标记位点之间的分子运动。偏振方法利用荧光偏振来跟踪单个分子的取向。[5±9]以前已经使用偏振方法来研究附着在结合到玻璃表面的DNA链上的荧光染料的再取向动力学。[10这些表面研究足够灵敏，揭示了染料Cy5的吸收和发射偶极子的五度偏移。在此，我们使用偏振方向连续变化的线偏振激光来激发与蛋白质结合的染料分子或外来荧光团。荧光信号被激发光束的偏振调制的程度是荧光团在偏振调制的时间尺度上的迁移率的量度。具有固定取向的荧光团在偏振取向与染料的跃迁偶极对齐时经历最大激发，并且在偏振与染料分子的跃迁偶极正交时经历最小激发。跃迁偶极的快速重新取向使吸收概率随机化，从而消除了固定荧光团所经历的调制。因此，跟踪荧光团的取向迁移率是实时跟踪单分子动力学的有效手段。
Single-molecule spectroscopy is increasingly used to probe the dynamics of individual molecules,[1] and spectroscopic techniques that are sensitive to the motion of single molecules are important for detection of these processes. Several singlemolecule methods are capable of tracking molecular motions in real time. Fluorescence-intensity trajectories of single molecules can be analyzed to characterize underlying dynamics.[2] Fluorescence resonance energy transfer, which monitors distance changes between two fluorophores,[3±5] can track molecular motions between two dye-labeled sites on a protein. Polarization methods make use of fluorescence polarization to track the orientation of single molecules.[5±9] Polarization methods have been used previously to study reorientational dynamics of fluorescent dyes attached to DNA strands bound to a glass surface.[10±12] These surface studies were sensitive enough to reveal a five-degree offset in the absorption and emission dipoles of the dye Cy5.Herein, we use a linearly polarized laser of which the orientation of the polarization is continuously varying to excite a dye molecule or an extrinsic fluorophore bound to a protein. The extent to which the fluorescence signal is modulated by the polarization of the excitation beam is a measure of the mobility of the fluorophore on the timescale of the polarization modulation. A fluorophore with fixed orientation experiences maximum excitation when the orientation of the polarization aligns with the transition dipole of the dye and minimum excitation when the polarization is orthogonal to the transition dipole of the dye molecule. Fast reorientation of the transition dipole randomizes the absorption probability, thus eliminating the modulation which is experienced by stationary fluorophores. Tracking the orientational mobility of a fluorophore is thus an effective means of following single-molecule dynamics in realtime.
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DOI：
10.1073/pnas.96.3.893
发表时间：
1999-02-02
影响因子：
11.1
作者：
Ha, TJ;Ting, AY;Weiss, S
通讯作者：
Weiss, S
天然红细胞鬼膜中质膜 Ca-ATP 酶的钙调蛋白结合域的动态结构。
影响因子：
2.9
作者：
Y. Yao;J. Gao;T. Squier
通讯作者：
T. Squier
单染料分子的取向成像和重新取向动力学
影响因子：
3.3
作者：
Kenneth D. Weston;L. Goldner
通讯作者：
L. Goldner
影响因子：
2.9
作者：
Enderlein, J;Sauer, M
通讯作者：
Sauer, M
直接观察单荧光核苷酸类似物分子与DNA聚合酶I的相互作用
影响因子：
2.8
作者：
J. Ye;Yuji Yamane;Masayo Yamauchi;H. Nakatsuka;M. Ishikawa
通讯作者：
M. Ishikawa