Fig. 2. The effects of amino acid charge and length on the voltage-dependent optical signal. (A) Optical traces of the V220D (black), V220E (red), V220K (blue), and V220R (pink) mutations. HEK293 cells expressing the appropriate GEVI were whole-cell voltage clamped and subjected to voltage steps as indicated. Bottom is a Boltzman fit of the normalized optical signal for V220D and V220E showing that the length of the side chain affects the voltage dependence of the response. Dark lines are the average of at least four cells. Shaded area is the standard error of the mean. (B) Optical traces of charged mutations to the V219 position. (C) Optical traces of charged mutations to the L221 position.
© Exp Neurobiol
