The invention discloses a method for improving the
solubility and
thermal stability of sweet
protein, and belongs to the technical field of
biosynthesis, the method comprises the following steps: constructing a
gene tandem recombinant
plasmid containing a monellin x-3C-sfGFP-3C-monellin y
expression cassette, x is greater than or equal to 1, y is greater than or equal to 1, 5 is greater than or equal to x + y is greater than or equal to 3, a 3C
protease recognition sequence is also inserted between adjacent copies of monellin, and each monellin is connected with a purification tag; the
gene tandem recombinant
plasmid is transformed into
escherichia coli and inducible expression is carried out, thalli are split and purified to obtain
fusion protein, 3C
protease is used for
enzyme digestion, and the
target protein is obtained after re-purification. The
total protein yield and the
solubility proportion are remarkably improved by adopting a series construction mode of plasmids, meanwhile, the stability of monellin is effectively improved, the purification step is simpler and more convenient, and the method is suitable for industrial production.