In this video, we describe the fluorescence anisotropy technique to study the interactions between the fluorophore-tagged Shwachman-diamond syndrome (SBDS) protein and the elongation factor-like 1 GTPase (EFL1). On incubating SBDS proteins with gradually increasing concentrations of EFL1, a steady increase in anisotropy is observed, indicating a successful interaction between the two proteins.
Protocol
1. Labeling of SBDS-FlAsH with the FlAsH Fluorescent Dye 4',5'-Bis(1,3,2 dithioarsolan-2-yl) Fluorescein Mix 3 nmol of the SBDS-FlAsH protein (the FlAsH-tag corresponds to the tetracysteine motif Cys-Cys-Pro-Gly-Cys-Cys genetically engineered in the C-terminus of the recombinant SBDS protein) with 3 nmol of the 4',5'-bis(1,3,2 dithioarsolan-2-yl) fluorescein dye in 5 µl volume of Anisotropy buffer (50 mM Tris-HCl pH 7.5, 300 mM NaCl, 5 mM MgCl2, 10% glycerol, 5 mM β-mercap…