MONMOUTH JUNCTION, N.J. — Proteomic analysis of urinary proteins is a promising tool to study renal pathophysiology inorder to determine biomarkers of renal disease. Urine specimens provide noninvasive approach for correlating physiology, pathology, clinical proteomics/peptidomics in urology and nephrology. Identities and abundance levels of isolated proteins from the ultrafiltrate of plasma or urinary tract are indicators of diseases associated with renal function and overall health of individuals. Biotech Support Group has developed UPCK™ Urine Protein Concentration Kit. UPCK™ Urine Protein Concentration reagent enriches many fold urine proteins in <60 minute bind, wash and elute protocol and is linearly scaleable up or down.

Potential applications of UPCK™ Urine Protein Concentration Kit include:

1. Albumin and uromodulin are examples of abundant proteins which obscure less concentrated, biologically more informative proteins (secreted cytokine s and hormones). UPCK™ Urine Protein Concentration Kit could potentially concentrate urinary exosomes , high-molecular-weight complexes from soluble peptides and proteins such as albumin and uromodulin from the bulk of the proteome.
2. Researchers could study and analyze proteins after using UPCK™ Urine Protein Concentration Kit for the detection of proteins from human urine such as membrane, extracellular, lysosomal, plasma membrane proteins in exosomes, renotubular trafficking proteins (uromodulin, cubilin and megalin/LRP2), serum-filtered enzymes and carriers (bikunin/AMBP, aminopeptidase N, ceruloplasmin, apolipoproteins and immunoglobulins), extracellular structural components (perlecan, glial fibrillary acidic proteins), secreted molecules such as CD44, tetraspanin, lysosomal-associated membrane proteins and cystatin C, beta(2)-microglobulin, urinary protein 1, retinol-binding protein etc.
3. Research by Pisitkun et al., used ultracentrifugation and LC-MS/MS to identify 295 highly abundant unique proteins isolated from urinary exosomes and Adachi et al., identified more than 1500 unique proteins from ultrafiltered urine with a high degree of accuracy by using a hybrid linear ion trap-Orbitrap (LTQ-Orbitrap) mass spectrometer.
4. Examples of urinary proteins having clinical significance include:
   
   1. Tubular and glomerular integrity is maintained by claudin, a protein which maintains tight junction function.
   2. The cause of renal failure and pathogenesis of polycystic kidney disease is linked to collectrin, a homolog of the angiotensin-converting enzyme-related carboxypeptidease.
   3. Renal glucosuria pathology is linked to SLC5A2, a tubular sodium–glucose transporter .
5. Subsequent two-dimensional gel electrophoresis coupled to mass spectrometry (2DE-MS), surface-enhanced laser desorption/ionization coupled to mass spectrometry (SELDI-MS), liquid chromatography coupled to mass spectrometry (LC-MS), capillary electrophoresis coupled to mass spectrometry (CE-MS), protein microarrays and biomolecular interaction analysis mass spectrometry (BIA/MS) allow researchers to identify candidate biomarkers(tubularproteins, cytokines, growth factors and inflammatory mediators).

Use UPCK™ Urine Protein Concentration Kit is ideal for the characterization of the human urinary proteome as an alternative to ultrafiltration and solvent precipitation.

Suggested References

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2. Decramer, S., Gonzalez de Peredo, A., Breuil, B., Mischak, H. et al., Urine in clinical proteomics. Mol. Cell. Proteomics 2008, 7, 1850–1862
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10. Adachi, J., Kumar, C., Zhang, Y., Olsen, J. V., Mann, M., The human urinary proteome contains more than 1500 proteins, including a large proportion of membrane proteins. Genome Biol. 2006, 7, R80.
11. Zhou H, Pisitkun T, Aponte A, Yuen PS, Hoffert JD, Yasuda H, Hu X, Chawla L, Shen RF, Knepper MA, et al. Exosomal Fetuin-A identified by proteomics: a novel urinary biomarker for detecting acute kidney injury. Kidney Int. 2006;70(10):1847–1857
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