Role of tRNAPro in pretransfer editing of alanine by prolyl-tRNA synthetase

Influence of cryoprotective agents on protein biosynthesis in Krebs-2 ascites carcinoma and wheat germ cell-free systems

Currently, the cell and tissue storage using the cryoprotective agents are quite common, in particular in reproductive technologies. Meanwhile the issue of safety when applying the CPAs remains open, since even in residual amounts after washing, they can affect the functioning of the most critical metabolic processes of a cell, in particular transcription and translation, which can be of great importance for further life and development of organs, tissues, cells. The goal was to study the effect of penetrating cryoprotective agents glycerol, ME₂SO, ethylene glycol, and non-penetrating PEG-400 on protein synthesizing activity in cell-free systems of Krebs-2 ascites carcinoma and wheat germ. In this study, we compared the effects of ME₂SO, PEG-400, glycerol, and ethylene glycol on protein biosynthesis in cell-free systems according to the incorporation of ¹⁴C-amino acids in total proteins. A reversible suppression of protein biosynthesis in Krebs-2 ascites carcinoma cells and wheat germ cell-free systems by CPAs PEG-400, ethylene glycol, glycerol and ME₂SO was found. This effect is shown to be stipulated by a direct influence of the studied CPAs on translation processes. ME₂SO, glycerol, ethylene glycol and PEG-400 were established to cause the Mg-dependent inhibition of protein biosynthesis in cell-free system of Krebs-2 ascites carcinoma cells in endogenous matrices and wheat germ ones in exogenous matrices. It has been shown that the mechanism of inhibiting action of CPAs on protein biosynthesis in cell-free systems is related to Mg^2+-dependent inhibition of tRNA aminoacylation, which when penetrating Me₂SO, glycerol and ethylene glycol CPAs are used, has a reversible character, and when PEG-400 being a hardly penetrating CPA is applied it is just partially recovered.