Monitoring protein interactions and dynamics with solvatochromic fluorophores

Abstract

Solvatochromic fluorophores possess emission properties that are sensitive to the nature of the local microenvironment. These dyes have been exploited in applications ranging from the study of protein structural dynamics to the detection of protein-binding interactions. While the solvatochromic indole fluorophore of tryptophan has been utilized extensively for in vitro studies to advance our understanding of basic protein biochemistry, the emergence of new extrinsic synthetic dyes with improved properties in conjunction with recent developments in site-selective methods to incorporate these chemical tools into proteins now open the way for studies in more complex systems. Herein we discuss recent technological advancements and their application in the design of powerful reporters, which serve critical roles in modern cell biology and assay development.

Fluorescent Amino Acids: Modular Building Blocks for the Assembly of New Tools for Chemical Biology

“…38 These phthalimide and naphthalimide-based FlAAs have also been incorporated into peptides recognizing PDZ and SH2 domains revealing their versatility in diverse applications. [39][40][41][42] The success of the dimethylaminonaphthalimide family led to their further exploration as environment-sensitive FlAAs. For example, the 4-(N,Ndimethylamino)naphthalimide amino acid (4-DMNA) was developed to complement 4-DAPA and 6-DMNA, and also yielded excellent improvements in stability towards hydrolysis and ease of synthesis.…”

Structure-related differences in the temperature-regulated fluorescence response of LCST type polymers

“…It was further proposed that intermolecular hydrogen-bonding of the carbonyl oxygen and/or the imide nitrogen with solvent molecules in protic solvents results in a drop of the quantum yield 26,29 accompanied by a pronounced red-shi of emission maxima. 21,23,31 Due to this strong environmental sensitivity, besides several reports regarding their use in chemosensors for detection of metal ions, 30,32,33 these uorophores were also exploited as a tool for monitoring protein-protein interactions, 27,34 or as a potential sensor for DNA. [35][36][37] Also, they have recently been used to signal the pH-induced conformational changes of a protein.…”

Choosing the right fluorophore for single-molecule fluorescence studies in a lipid environment

“…However, the mechanisms by which the cell membrane modulates the structure, the dynamics and the function of large families of transmembrane proteins, e.g., G protein coupled receptors, to sustain important cellular processes, e.g., signaling, are still not fully understood [3]. With the development of various fluorescence microscopy and spectroscopy techniques and the advent of brighter and photostable dye labels, investigations of protein-lipid interactions using fluorescently labeled proteins have become common [5][6][7][8]. This enabled quantitative studies of conformations and dynamics of proteins in lipid vesicles, lipid nanodiscs and in live cells via fluorescence techniques [9][10][11][12].…”