Expression system of bacillus thur ingiens (Bt) insecticidal protein Cry1Ac-a

Abstract

The invention belongs to the field of molecular biology and biotechnology, and relates to an expression system of a bacillus thur ingiens (Bt) insecticidal protein Cry1Ac-a. The expression system of the Bt insecticidal protein Cry1Ac-a is synthetic. The expression system of the Bt insecticidal protein Cry1Ac-a comprises expression vectors and protein Cry1Ac-a gene fragments. The protein Cry1Ac-a gene fragments are obtained by optimization according to an escherichia coli codon preference. An optimized protein Cry1Ac-a comprises 615 amino acids, and has molecular weight of 68.7KD and an isoelectric point of 5.42. The invention also relates to a method for high-efficiency expression of a protein by recombinant strain IPTG induction. The expression system of the Bt insecticidal protein Cry1Ac-a overcomes the defect of an escherichia coli expression codon preference, obviously reduces a secondary structure of a mRNA, realizes high expression of the protein Cry1Ac-a in escherichia coli, and provides a feasible solution scheme for high-efficiency and low-cost expression of the protein Cry1Ac-a.

Description

technical field [0001] The invention belongs to the field of molecular biology and biotechnology, and specifically relates to an expression system of artificially synthesized Bt insecticidal protein Cry1Ac-a, including artificially synthesized Bt The gene of the insecticidal protein contains the expression vector of the gene and the product expressed by the gene. Background technique [0002] Bacillus thuringiensis ( Bacillus thur iniens , Bt ) Insecticidal crystal protein has high specific insecticidal activity to many important agricultural pests, but it is completely harmless to humans, vertebrates, and plants, and can be completely degraded in nature, so it is widely used in pest control. change Bt The application of crops has opened up new avenues for pest control and reduced the use of chemical pesticides. With the development of rice transgenic technology research and development and the cultivation of transgenic varieties, my country has cultivated a number of...

AI Technical Summary

Problems solved by technology

The imported high-purity Cry1Ac protein is very expensive, and it is also different from the insecticidal protein produced by the coding gene transferred into rice

However, the protein extracted from Bacillus thuringiensis is structurally different from the Cry1Ac protein transformed into rice, and as a protoxin, it cannot show biological activity outside the host body.

Miscellaneous proteins are introduced after activation by enzymatic digestion, so it cannot be directly used for scientific evaluation experiments

Due to the existence of impurity proteins, it needs to be separated and purified again to ensure the purity of the protein, and the operation is cumbersome and complicated.

besides, Bt The proportion of toxic protein in the total soluble protein of plants is very small, it is difficult to directly isolate from transgenic plants, and it is difficult to directly obtain enough insecticidal proteins from transgenic crops

Common protein prokaryotic expression system is also difficult to obtain high-efficiency expression of Cry1Ac protein due to the problem of codon bias

Images