Method for improving persistency of glutamic acid decarboxylase activity

Abstract

The invention provides a method for improving the persistency of glutamic acid decarboxylase activity. The method comprises the steps of: connecting a glutamic acid decarboxylase gene (Genbank No.: NM_168056) (with a conventional method) to the N end of a saccharomyces cerevisiae cell wall component FLO sequence (Genbank No.: S73336), then inserting the glutamic acid decarboxylase gene (in a conventional approach) to the C end of a downstream MF alpha1 signal peptide sequence (Genbank No.: M17301) of the GAL1 promoter (Genbank No.: AY428072) of a saccharomyces cerevisiae expression vector so as to construct an expression cassette, which is, from the N end to the C end, as follows: GAL1 promoter + MF alpha1 signal peptide sequence + glutamic acid decarboxylase gene + FLO sequence; shifting a yeast plasmid containing the expression cassette into the saccharomyces cerevisiae cell. According to the invention, the glutamic acid decarboxylase is connected to the saccharomyces cerevisiae cell wall component FLO, so that as long as the saccharomyces cerevisiae cell maintains alive, the glutamic acid decarboxylase can keep active.

Description

technical field [0001] The invention relates to the field of bioengineering, in particular to a method for exposing and expressing glutamic acid decarboxylase on the outer surface of the cell wall of Saccharomyces cerevisiae to improve the activity persistence of the enzyme. Background technique [0002] γ-aminobutyric acid is a natural health factor, which has obvious blood pressure lowering effect. Glutamic acid can be converted into γ-aminobutyric acid in one step by glutamic acid decarboxylase. However, the currently used glutamic acid decarboxylase has the problem of insufficient enzyme activity persistence. There are two ways of recombinant expression of various enzymes including glutamic acid decarboxylase: intracellular expression and secretory expression. The recombinant expression of these two enzymes makes there is no relationship between the enzyme molecule and the host cell, that is, the enzyme molecule is not the host components of cells and are thus easily i...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem of insufficient activity of existing glutamate decarboxylase, the present invention provides a technique for making glutamate decarboxylase an integral part of Saccharomyces cerevisiae cells. Can maintain activity, thereby significantly improving the persistence of glutamic acid decarboxylase activity