<scp>R</scp> eduction of <scp>GAPDH</scp> in lenses of <scp>P</scp> arkinson's disease patients: <scp>A</scp> possible new biomarker

Background We previously showed that the protein pattern of lenses removed in cataract surgery differs between patients with Parkinson&#39;s disease and age-matched controls. In this study, we identified the protein reduced in abundance in the 34- to 37-kDa gel band. Methods During cataract surgery (phacoemulsification), we collected the rinsing fluid and lens particles from the eyes of PD patients and controls. Residual lens fragments in the supernatant of 3 PD patients and aged-matched controls were studied for protein profiles using liquid chromatography-mass spectrometry and Western blots. Results We identified glyceraldehyde-3-phosphate dehydrogenase by mass spectrometry as the protein reduced in abundance and verified this finding in Western blots. Conclusions Glyceraldehyde-3-phosphate dehydrogenase has been implicated in PD development. The reduction of glyceraldehyde-3-phosphate dehydrogenase in the lenses of PD patients may be a new biomarker for PD and might also indicate an important role for this protein in PD development. &#169; 2016 International Parkinson and Movement Disorder Society