ZB 10 - Soft Condensed Matter (R. Holyst)

Nanoscopic Approach to Quantification of Equilibrium and Rate Constants of Complex Formation at Single-Molecule Level

Author(s): Zhang, Xuzhu and Sisamakis, Evangelos and Sozanski, Krzysztof and Holyst, Robert
Title: Nanoscopic Approach to Quantification of Equilibrium and Rate Constants of Complex Formation at Single-Molecule Level
Abstract: Equilibrium and rate constants are key descriptors of complex-formation in a variety of chemical and biological reactions. However, parameters are difficult to quantify, especially in the locally heterogeneous, and dynamically changing living matter. Herein, address this challenge by combining stimulated emission depletion nanoscopy with fluorescence correlation spectroscopy (FCS). STED the length-scale of observation to tens of nanometres (3D) and the time-scale to microseconds, with direct, control. This allows one to distinguish diffusional and binding of complex-formation, even at reaction rates higher by an of magnitude than in confocal FCS. We provide analytical formulas for probes undergoing diffusion-reaction under STED condition. We support the theoretical analysis of STED-FCS data on a model system of dye-icelle, where we the equilibrium and rates constants. Our work paves a promising toward quantitative characterization of molecular interactions in vivo.
Pages: 5785-5791
Journal: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Publisher: AMER CHEMICAL SOC
Addres: 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Volume: 8
ID: ISI:000417671200016
Year: 2017
DOI: 10.1021/acs.jpclett.7b02742