A cell-free protein synthesis system from insect cells.

The newly developed Transdirect in vitro translation system for mRNA templates utilizes an extract from cultured Spodoptera frugiperda 21 (Sf21) insect cells. An expression vector, pTD1, which includes a 5'-untranslated region (UTR) sequence from a baculovirus polyhedrin gene as a translational enhancer, designed to obtain maximum performance from the insect cell-free protein synthesis system. The combination of insect cell extract and the expression vector results in protein productivity of about 50 μg/mL of the translation reaction mixture. This is the highest protein productivity yet recorded among commercialized cell-free protein synthesis systems based on animal extracts.