Cellulose Acetate Membrane Electrophoresis Based Urinary Proteomics for the Identification of Characteristic Proteins.

Analysis of urinary proteins using cellulose acetate membrane electrophoresis (CAME) is a useful and challenging method for the recognition of damaged sites in the kidney. However, protein content of each CAME fraction is still not completely understood. In this study, an effective method of protein extraction from each band fractionated by CAME was established, which enabled us to examine the extracted proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. Proteins were extracted from the gel and analyzed by mass spectrometry. In all, 31 proteins were identified, including 20 urinary proteins that were newly identified in the CAME-based analysis. This methodology was useful for identifying the proteins responsible for creating unique bands on CAME in a urine sample of a patient with drug-induced interstitial nephritis. These findings provide in-depth characterization of urinary protein contents in each CAME fraction.