Analysis of yeast protein kinases using protein chips

We have developed a novel protein chip technology that allows the high-thro ughput analysis of biochemical activities, and used this approach to analys e nearly all of the protein kinases from Saccharomyces cerevisiae. Protein chips are disposable arrays of microwells in silicone elastomer sheets plac ed on top of microscope slides. The high density and small size of the well s allows for high-throughput batch processing and simultaneous analysis of many individual samples. Only small amounts of protein are required. Of 122 known and predicted yeast protein kinases, 119 were overexpressed and anal ysed using 17 different substrates and protein chips. We found many novel a ctivities and that a large number of protein kinases are capable of phospho rylating tyrosine. The tyrosine phosphorylating enzymes often share common amino acid residues that lie near the catalytic region. Thus, our study ide ntified a number of novel features of protein kinases and demonstrates that protein chip technology is useful for high-throughput screening of protein biochemical activity.