Sharma Arjun, Enderlein Jörg, Kumbhakar Manoj
Radiation & Photochemistry Division, Bhabha Atomic Research Center , Mumbai 400085, India.
Homi Bhabha National Institute , Training School Complex, , Anushaktinagar, Mumbai 400094, India.
J Phys Chem Lett. 2017 Dec 7;8(23):5821-5826. doi: 10.1021/acs.jpclett.7b02430. Epub 2017 Nov 16.
Fluorescence correlation spectroscopy (FCS) of photoinduced electron transfer (PET) between the dye Atto-655 and the amino acid tryptophan has been extensively used for studying fast conformational dynamics of small disordered peptides and proteins. However, a precise understanding of the quenching mechanism and its exact rates that would explain ensemble as well as single-molecule spectroscopy results is still lacking. In this contribution, a general unified model for intermolecular PET between Atto-655 and tryptophan is developed, which involves ground-state complex formation, quenching sphere of action, and dynamic quenching at the single-molecule level. We present measurements of fluorescence antibunching, fluorescence lifetime, and steady-state fluorescence intensity and absorbance and demonstrate that our model is capable to describe all results in a global and coherent manner.
染料Atto-655与氨基酸色氨酸之间光诱导电子转移（PET）的荧光相关光谱（FCS）已被广泛用于研究小的无序肽和蛋白质的快速构象动力学。然而，对于能够解释系综以及单分子光谱结果的猝灭机制及其确切速率仍缺乏精确的理解。在本论文中，我们建立了一个Atto-655与色氨酸之间分子间PET的通用统一模型，该模型涉及基态复合物形成、作用猝灭球以及单分子水平的动态猝灭。我们展示了荧光反聚束、荧光寿命、稳态荧光强度和吸光度的测量结果，并证明我们的模型能够以全局且连贯的方式描述所有结果。
