Development of a cell-free translation system from Cucumis melo: preparation, optimization and evaluation of sensitivity to some translational inhibitors

Abstract

A very active cell-free translation system was prepared from 4–5-day-old embryonic axes of melon ( Cucumis melo L.), a species whose dry seeds contain a powerful translational inhibitor. The system was optimized for Mg 2+, K +, NH 4 +, high speed supernatant, total wheat germ tRNA, time and temperature. Using a 30 000 × g supernatant, the system translates endogenous messengers and polyuridylic acid very efficiently. Melon ribosomes were inhibited in vitro by several well-known eukaryotic inhibitors including melonin, the protein inhibitor present in the dry seeds of C. melo. Our results suggest that the protein inhibitor does not affect the activity of melon ribosomes neither in vivo nor during their isolation.