FIGURE 1.
Proteomic analysis. A 2-D PAGE-based proteomic approach was initially used for phosphoprotein detection and identification. (A) 2-D gels obtained using ocular hypertensive and control samples after protein gel stain or phosphoprotein staining. Proteins revealed by phosphoprotein staining (Pro-Q Diamond; Invitrogen/Molecular Probes) were then identified through peptide mass fingerprinting and peptide sequencing. The five spots shown in the box correspond to different isoforms of 14-3-3. Comparison of phosphoprotein-stained 2-D gels using ocular hypertensive and control samples indicates many other proteins in addition to 14-3-3 (black arrows) that exhibit new or increased phosphorylation in ocular hypertensive eyes. Consistent with the results of 2-D gel analysis, experiments through a gel-free proteomic technique identified the same 14-3-3 proteins. (B) Results of gel-free analysis using tandem mass spectrometry.