Multiplexed Nucleic Acid Programmable Protein Arrays

Yu, Xiaobo; Song, Lusheng; Petritis, Brianne; Bian, Xiaofang; Wang, Haoyu; Viloria, Jennifer; Park, Jin; Bui, Hoang; Li, Han; Wang, Jie; Liu, Lei; Yang, Liuhui; Duan, Hu; McMurray, David N.; Achkar, Jacqueline M.; Magee, Mitch; Qiu, Ji; LaBaer, Joshua

Protein microarrays can be classified into two different types, purified or cell-free, based on whether the proteins are produced in vivo or in vitro, respectively [16] . Purifying proteins is labor-intensive, requires method optimization and multiple manipulations, exhibits highly variable yields of different proteins, and may not result in naturally-folded or functional mammalian products due to expression in non-mammalian systems (e.g., E. coli, yeast). Cell-free protein microarrays overcome these challenges by depositing RNA or DNA on the slide surface and rapidly expressing them just before an experiment (~2 h) through the use of various cell-free expression systems (e.g., lysate from wheat germ, insect cells, rabbit reticulocyte and human cells). Compared to purified protein microarrays, cell-free protein microarrays are more likely to produce naturally-folded mammalian proteins due to the decreased sample manipulation and use of enhanced cell extracts with native chaperone proteins. Moreover, the use of nucleic acids vastly simplifies the production of custom arrays since any protein can be produced as long as the gene-of-interest is synthesized; for example, arrays can be produced that represent a specific proteome or signaling pathway [17] [18] [19] [20] .