Application of preparative electrophoresis for clinical proteomics in urine: Is it feasible?

Abstract

Urine samples are easily attainable which makes them ideal substrates for biomarker research. Various techniques have been employed to unravel the urine proteome and identify disease biomarkers. Even though the presence of high abundance proteins in urine is not so pronounced as in the case of plasma, the presence of proteolytic products, many of which at low abundance, along with numerous frequently random chemical modifications, makes the analysis of urinary proteins challenging. To facilitate the detection of low abundance urinary proteins, in the study presented herein we applied two different electrophoretic techniques, preparative Lithium Dodecyl Sulfate (LDS)-PAGE in combination with 2-DE for urinary protein separation and enrichment. Our results indicate the effectiveness of this approach for the enrichment of low abundance and low molecular weight proteins and peptides in urine, and contribute towards the establishment of a urinary proteomic database. The application of this technique as a biomarker discovery tool faces several challenges: these include down-scaling of the technique, possible recompensation for the consequent expected decrease in protein resolution, by optimizing steps of the experimental workflow as well as getting a good understanding of the technical variability of the technique. Under these conditions, preparative electrophoresis can become an effective tool for clinical proteomics applications.

Keywords

• preparative electrophoresis
• 2de
• urine
• clinical proteomics
• proteome mining