Secretory Expression Of The Glucan Endo-1,3-Beta-D-Glucosidase Gene Of Secale Cereale In Yeast Pichia Pastoris

Abstract

For survival in cold conditions, many organisms have developed unique adaptive mechanisms based on the synthesis of antifreeze proteins, peptides and glycoproteins that prevent ice formation at negative temperatures. These molecules tend to bind ice crystals and lower the freezing point of the solution without the formation of large crystals. Antifreeze proteins (AFP) were found in almost all types of living organisms, including insects, fungus, yeasts, bacteria and plants. The gene of antifreeze protein - glucan endo-1,3-beta-D-glucosidase (ScGlu-3) from Secale cereale was cloned into shuttle vector pPICZαA. The competent cells of yeast Pichia pastoris GS115 were transformed and the producer strain was obtained, which secreted of ScGlu-3 into the culture medium using 3% methanol as the only carbon source. It was found by western blotting that the maximum accumulation of ScGlu-3 in the culture occurs after 48 hours of fermentation on a medium with methanol. Established that rScGlu-3 precipitates at 50-65% of ammonium sulfate.