Figure 2
From: Protein–Protein Affinity Determination by Quantitative FRET Quenching

Fluorescence emission from the mixture of CyPet-SUMO1 and YPet-Ubc9. (A) Spectrum changes of the mixture of CyPet-SUMO1 and YPet-Ubc9 proteins at increasing amount of acceptor when excited at 414 nm. The CyPet-SUMO1 concentration is fixed at 1.5 μM, and YPet-Ubc9 concentrations range from 0 to 4 μM. (B) Emission intensity of CyPet-SUMO1 at 475 nm (Ex = 414 nm) decreases at different concentrations of CyPet-SUMO1 with increasing YPet-Ubc9 concentrations. ● 0.5 μM of CyPet-SUMO1, ■1 μM of CyPet-SUMO1, and ▲ 1.5μM of CyPet-SUMO1. (C) The emissions of CyPet and YPet when excited at 441 nm.