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

Background: 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.

Methods: 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.

Results: 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.

Conclusion: 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.