Gene for coding glutamine dipeptide biosynthetic enzyme and application thereof

Abstract

The invention discloses a gene for coding a glutamine dipeptide biosynthetic enzyme and application thereof. The nucleotide sequence of the gene is shown as SEQ ID NO.1. The invention further discloses an amino acid sequence coded by the gene, and provides a recombinant vector containing the gene, recombinant escherichia coli, and a method for performing biotransformation to synthesize the glutamine dipeptide by using the gene. The gene and the application of a recombinant bacterial strain of the gene have the advantages of high mol conversion rate, high reaction speed, easy separation, low cost and the like. In the synthesis method, the maximum mol conversion rate of the glutamine dipeptide can reach 83.3 percent; meanwhile, the thalli can be applied to the catalytic synthesis of the glutamine dipeptide again after the circulation recovery; in addition, the catalytic activity is stable. Therefore high market competitive power and application values are realized; a foundation is laid for the industrial production of the glutamine dipeptide.

Description

technical field [0001] The invention relates to a biosynthetic method of dipeptide, in particular directly using recombinant Escherichia coli as a whole-cell catalyst to efficiently synthesize dipeptide, which belongs to the field of biotechnology. Background technique [0002] Glutamine dipeptide (L-Ala-Gln), also known as N(2)-L-alanyl-L-glutamine, has the advantages of high solubility, water solubility and strong thermal stability and has gradually replaced glutamine (L -Gln) has become the main parenteral nutrition drug. [0003] At present, the synthesis of CG dipeptide mainly adopts chemical synthesis and biological enzyme catalysis. The production of CG dipeptide by chemical synthesis has many reaction steps, many by-products, highly toxic reagents and is not environmentally friendly (Tang Guo. Synthesis and reaction research of N(2)-L-alanyl-L-glutamine dipeptide. Xiamen University , 2004; Chinese patent, C-glutin dipeptide synthesis method, CN1392156A). [0004] ...

AI Technical Summary

Problems solved by technology

The production of CG dipeptide by chemical synthesis has many reaction steps, many by-products, highly toxic reagents and is not environmentally friendly (Tang Guo. Synthesis and reaction research of N(2)-L-alanyl-L-glutamine dipeptide. Xiamen University ,2004; Chinese Patent, Synthetic Method of C-Gludipeptide, CN1392156A)

[0004] However, the biological enzyme catalysis method also has the disadvantages of large amount of enzyme, low peptide productivity, and can only catalyze the synthesis of some highly hydrophobic amino acids.

In recent years, foreign researchers have obtained an amino acid ligase (Lal) from Bacillus subtilis, and developed a patented technology for fermenting and producing dipeptides. The production cost is still high, and it cannot be widely used in the market (Tabata K, Hashimoto S. Fermentative production of L-alanyl-L-glutamine by a metabolically engineered Escherichia coli strain expressing L-amino acid α-ligase. Applied and environmental microbiology, 2007, 73 (20):6378-6385.)

[0005] CN104480075A and CN105274174A disclose two kinds of bioenzyme-catalyzed methods for synthesizing glutamic acid dipeptide, which adopts bioenzyme freeze-dried powder or bioenzyme buffer to carry out catalytic reaction, but because the cost of enzyme separation and purification is high, and it is difficult to recycle and reuse after the reaction, it is not suitable for actual industrial production

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