Combinatorial hexapeptide ligand libraries (ProteoMiner): an innovative fractionation tool for differential quantitative clinical proteomics.

Blood serum samples are the major source for clinical proteomics approaches, which aim to identify diagnostically relevant or treatment-response related proteins. But, the presence of very high-abundance proteins and the enormous dynamic range of protein distribution hinders whole serum analysis. An innovative tool to overcome these limitations, utilizes combinatorial hexapeptide ligand libraries (ProteoMiner). Here, we demonstrate that ProteoMiner can be used for comparative and quantitative analysis of complex proteomes. We spiked serum samples with increasing amounts (3 microg to 300 microg) of whole E. coli lysate, processed it with ProteoMiner and performed quantitative analyses of 2D-gels. We found, that the concentration of the spiked bacteria proteome, reflected by the maintained proportional spot intensities, was not altered by ProteoMiner treatment. Therefore, we conclude that the ProteoMiner technology can be used for quantitative analysis of low abundant proteins in complex biological samples.