The effect of DTT in protein preparations for proteomic analysis: Removal of a highly abundant plant enzyme, ribulose bisphosphate carboxylase/oxygenase

Rubisco is a major photosynthetic plant enzyme in the chloroplasts, catalyzing a photosynthetic reaction through carboxylation and oxygenation in the leaves. Despite its biological importance, its high abundance causes difficulties in the proper separation of protein mixtures during 2-dimensional gel electrophoresis (2-DE). Here, we resolved those plant soluble proteins by efficiently removing Rubisco. This resulted in a high quality and resolution of 2-DE gels. Rubisco removal was achieved through aggregation in the presence of a high DTT concentration, which subsequently increased the visualization of less abundant proteins and reduced horizontal streaking. This simple method may provide a means for finding more biologically important protein targets via plant proteomics.