Fluorescence Quenching

Abstract

Methods of fluorescence quenching are very popular because rather simple experiments are used here to obtain valuable information on structural and dynamic properties of proteins. Quantum yield and fluorescence lifetime of proteins may be considerably lowered by addition into the medium of substances, such as certain ions (iodide, cesium), molecular oxygen, acrylamide, etc. In this case it is possible to obtain data both on the relationship of protein chromophores to protein-solvent interface (surface and buried chromophores) and on the protein dynamic structure responsible for the fluorescence quenching of internal chromophore groups. Thermal fluorescence quenching in proteins is associated with intramolecular dynamics and is of great interest for investigation. Burstein (1977) Lehrer and Leavis (1978), and Eftink and Ghiron (1981b) reviewed many scientific papers on fluorescence quenching. This chapter is concerned, in brief, with the physical principles and mechanisms of quenching, properties of quenchers, as well as with the main results and trends of research.