Medintz Igor L, Pons Thomas, Susumu Kimihiro, Boeneman Kelly, Dennis Allison, Farrell Dorothy, Deschamps Jeffrey R, Melinger Joseph S, Bao Gang, Mattoussi Hedi
Center for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, DC 20375.
J Phys Chem C Nanomater Interfaces. 2009 Oct 5;113(43):18552-18561. doi: 10.1021/jp9060329.
We characterized the resonance energy transfer interactions for conjugates consisting of QD donors self-assembled with three distinct fluorescent protein acceptors: two monomeric fluorescent proteins, the dsRed derivative mCherry or yellow fluorescent protein and the multi-chromophore b-phycoerythrin light harvesting complex. Using steady-state and time-resolved fluorescence, we showed that nonradiative transfer of excitation energy in these conjugates can be described within the Förster dipole-dipole formalism, with transfer efficiencies that vary with the degree of spectral overlap, donor-acceptor separation distance and the number of acceptors per QD. Comparison between the quenching data and simulation of the conjugate structures indicated that while energy transfer to monomeric proteins was identical to what was measured for QD-dye pairs, interactions with b-phycoerythrin were more complex. For the latter, the overall transfer efficiency results from the cumulative contribution of individual channels between the central QD and the chromophores distributed throughout the protein structure. Due to the biocompatible nature of fluorescent proteins, these QD-assemblies may have great potential for use in intracellular imaging and sensing.
我们对由量子点（QD）供体与三种不同荧光蛋白受体自组装形成的共轭物的共振能量转移相互作用进行了表征：两种单体荧光蛋白，即dsRed衍生物mCherry或黄色荧光蛋白，以及多发色团的b-藻红蛋白光捕获复合物。通过稳态和时间分辨荧光，我们表明这些共轭物中激发能量的非辐射转移可以用Förster偶极-偶极形式来描述，其转移效率随光谱重叠程度、供体-受体分离距离以及每个量子点上受体的数量而变化。共轭物结构的猝灭数据与模拟结果之间的比较表明，虽然向单体蛋白的能量转移与量子点-染料对所测得的情况相同，但与b-藻红蛋白的相互作用更为复杂。对于后者，总体转移效率源于中央量子点与分布在整个蛋白质结构中的发色团之间各个通道的累积贡献。由于荧光蛋白具有生物相容性，这些量子点组装体在细胞内成像和传感方面可能具有巨大的应用潜力。
