TABLE 1.
Kir6.2-FP fusion protein stoichiometry and tetrameric FRET model
Where r = ratio of CFP to YFP containing subunits in transfected Cosm6 cells, calculated as the ratio of emission at 475 nm (excited at 430 nm, F430(475)) to the emission at 525 nm (excited at 480 nm, F480(525)); CnY4-n is the specific configuration of Kir6.2-CFP/Kir6.2YFP tetramers containing n CFP and 4-n YFP fluorophores; R is the distance between CFP and YFP fused at adjacent subunits of Kir6.2; R0 is the Förster distance of the CFP/YFP FRET pair, which is 30 Å with an orientation factor of 2/3; pCnY4-n is the probability of Kir6.2-C/YFP mixtures forming configurations that contain n CFP and 4-n YFP; ECnY4-nY is the effective FRET efficiencies of Kir6.2-C/Kir6.2YFP tetramers containing n CFP and 4-n YFP, determined by the YFP sensitized emission.
