Patent ID: 7807400

Claim:
A method of identifying a compound having the ability to inhibit guanine nucleotide exchange factor activity, comprising: a) contacting the compound with a first guanine nucleotide exchange factor and a GTPase and obtaining a baseline fluorescence measurement; b) contacting the first guanine nucleotide exchange factor and the GTPase without the compound and obtaining a baseline fluorescence measurement; c) adding a fluorophore-conjugated GTP to the components of (a) and (b), respectively; d) obtaining fluorescence measurements of the respective components of (c) over time; e) subtracting the respective baseline fluorescence measurements of (a) and (b) from the fluorescence measurements of (d); f) comparing the resulting fluorescence values of (e), wherein a decrease in the rate of fluorescence change with the compound as compared with the rate of fluorescence change without the compound identifies a compound potentially having the ability to inhibit guanine nucleotide exchange factor activity; g) repeating steps a-e with a second guanine nucleotide exchange factor; and h) comparing the resulting fluorescence values of (g), wherein no decrease in the rate of fluorescence change with the compound as compared with the rate of fluorescence change without the compound identifies a compound having the ability to inhibit guanine exchange factor activity.