Why does my protein precipitate when i add TEV protease to cleave the GST tag?

Upon incubation of my protein with O/N with TEV protease (in 50mM Tris, 0.5mM EDTA), in the morning i saw a white thready precipitated formed. After running the SDS gels, following coomassie...

29 June 2016 5,104 6 View