Expression vector stably replicated in corynebacterium diphtheriae and corynebacterium diphtheriae with expression vector

Abstract

The invention discloses an expression vector stably replicated in corynebacterium diphtheriae and corynebacterium diphtheriae with the expression vector. The expression vector comprises a replication origin DNA (deoxyribonucleic acid) sequence stably replicated in the corynebacterium diphtheriae, a DNA (deoxyribonucleic acid) sequence capable of expressing a peptide-mediated protein sequence and a DNA (deoxyribonucleic acid) sequence of a CRM197 recombinant protein coding gene; the expression vector stably replicated in the corynebacterium diphtheriae carried by the corynebacterium diphtheriae has the replication origin DNA (deoxyribonucleic acid) sequence stably replicated in the corynebacterium diphtheriae so that the expression vector is stably replicated in the corynebacterium diphtheriae; meanwhile, by the DNA (deoxyribonucleic acid) sequence capable of expressing the peptide-mediated protein sequence on the expression vector, the expressed CRM197 recombinant proteins carry out the secretory expression and secretes extracellularly so as to increase the expression quantity of the CRM 197 recombinant proteins; the purification process of the expressed CRM197 recombinant proteins is further simplified; the yield of the proteins is increased; and, the production time and the production cost are saved.

Description

technical field [0001] The invention relates to the field of vaccine production strains, in particular to an expression vector stably replicated in diphtheria bacillus and diphtheria bacilli carrying the vector. Background technique [0002] Corynebacterium diphtheriae is the pathogenic bacterium that causes diphtheria in children and belongs to the genus Corynebacterium. Its growth cycle is short and its reproduction speed is fast. [0003] The causative substance of diphtheria bacilli is mainly diphtheria toxin, which exists in the extracytoplasm in the form of secretory expression, and the protein secreted by diphtheria bacillus outside the cytoplasm is very small except for diphtheria toxin, which is very important for diphtheria toxin. The purification of diphtheria toxin is very favorable, so diphtheria bacillus is widely used in vaccine fermentation production as the production engineering strain of diphtheria toxin and diphtheria toxin mutant (CRM197). [0004] At p...

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Problems solved by technology

[0004] At present, the most commonly used expression systems for antigen fermentation production include Escherichia coli, plant cells, etc. The disadvantage is that the content of miscellaneous proteins is high, and most of them are expressed in cells or inclusion bodies, which requires a lot of time and effort for the later purification process. Manpower and material costs; while the establishment of a secreted expression system often requires the introduction of a guide peptide, but often requires fusion expression with the antigen protein, the guide peptide needs to be excised in the later process, which increases the complexity and complexity of the process. Difficulty of operation

So far, there is no report on the use of diphtheria bacteria to carry replicable plasmids for the research and application of antigen expression

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