PROTEINS OF RAT SERUM - I - ESTABLISHING A REFERENCE 2-DIMENSIONAL ELECTROPHORESIS MAP BY IMMUNODETECTION AND MICROBORE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ELECTROSPRAY MASS-SPECTROMETRY

In the present investigation, we have identified 56 major spots, or sp ot rows, corresponding to 22 proteins, in the 2-DE pattern of adult ma le rats. This was done mainly by applying two complementary techniques , namely immunoblotting and high performance liquid chromatography-mas s spectrometry (HPLC-MS) peptide mapping. Glycoproteins were character ized by affinity blotting with six lectins. We have also detailed how rat serum differs from human serum in two main respects: (i) relative abundance of individual proteins, which amounts in some cases to a com plete absence in either sample, and (ii) varying molecular parameters for homologous proteins. It was thus possible to establish a first-gen eration reference map of rat serum proteins, which can be accessed thr ough http://weber.u.washington.edu/similar to ruedilab/aebersold.html. We hope the present database will be a useful reference for the evalu ation of changes in serum protein distribution in the course of pharma cological and toxicological studies. The recognition of species-specif ic proteins appears of special relevance in this respect.