A protein with inhibitory activity on cell-free translation from cultured mycelia of the edible mushroom Tricholoma lobayense

Abstract

Cultured mycelia of the edible mushroom Tricholoma lobayense were extracted with cold saline. Proteins were precipitated from the extract by addition of (NH 4) 2SO 4. The precipitate was dissolved and dialyzed before ion exchange chromatography on DEAE-cellulose. Ability to inhibit translation in a rabbit reticulocyte lysate was located in the unadsorbed fraction which was then subjected to affinity chromatography on Affi-gel Blue gel. The strongest activity was again retained by the unadsorbed fraction. Ion exchange chromatography on CM-cellulose resulted in fractionation of this fraction into an unadsorbed and two adsorbed peaks. Cell-free translation inhibitory activity was concentrated in the fraction eluted with 100 mM NaCl in 10 mM NH 4OAc (pH 5.4). The translation-inhibitory protein possessed a molecular weight of 30 kDa as estimated by gel filtration using a fast protein liquid chromatography system and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.