A combinatorial library of artificial transcription factors (ATFs) was introduced into the bacterial cells that expressed the Akt1-GFP fusion protein. By measuring the level of fluorescence generated by the transformed E. coli cells, we were able to obtain clones in which ATFs increased the solubility of the Akt1. Our results show that ATF library is a useful tool for increasing the solubility of selected recombinant proteins in E. coli.