The protein expression profile of cynomolgus monkey embryonic stem cells in two-dimensional gel electrophoresis: a successful identification of multiple proteins using human databases

Abstract

Global gene and protein expression analyses have had great impacts on scientific progresses in this new era of bioinformatics. Although studies using murine and human materials can fully exploit the large volume of their databases, there are quite a few inconveniences for an investigation on non-human primate materials due to still insufficient data collections. Here we examined the availability of human databases for the protein identification process using the two-dimensional electrophoresis-based proteomic study in cynomolgus monkey embryonic stem (ES) cells. Querying public human protein databases, we successfully identified multiple protein spots via mass spectrometric analysis using MALDI-TOF apparatus. The results of the protein identification were confirmed by western blotting using polyclonal antibodies raised against human epitopes. Interestingly, the results of western blotting further identified the existence of previously unreported multiple isoforms of common proteins including glycolytic pathway enzymes. Thus, combined analyses of the mass spectrometry querying the Homo sapience databases and the western blotting using polyclonal antibodies is highly effective in determining protein expressions in monkey cells. Our success in obtaining a draft protein expression profile of cynomolgus monkey ES cells will contribute to the promotion of non-human primate ES cell researches.