A method for synthesizing L-carnosine in one step using L-amino acid ligase

Abstract

The invention discloses a method of synthesizing L-carnosine using L-amino acid ligase by a one-step method. The method comprises the steps of taking beta-alanine, L-histidine, ATP (adenosine triphosphate) and polyphosphate as raw materials, and MgCl2 as an activator, adding L-amino acid ligase and polyphosphate kinase, and synthesizing L-carnosine through an enzymatic reaction and coupled coupleunder conditions of a pH of 6.5-8.5 and a temperature of 30-45 DEG C. According to the method, a sequence optimized L-amino acid ligase gene is successfully expressed in escherichia coli, and beta alanine and L-histidine can be catalyzed to synthesize L-carnosine at one step. A substrate is not required to be methylated or subjected to group protection; ATP required by a catalytic reaction is continuously regenerated by allowing polyphosphate kinase to catalyze phosphorylation of ADP (adenosine diphosphate); cyclic regeneration of ATP can be achieved only by consuming a small amount of ADP; and a renewable raw material, sodium hexametaphosphate, is wide in source, low in cost, simple to operate and easy in large-scale production.

Description

technical field [0001] The invention relates to a method for synthesizing carnosine, in particular to a method for synthesizing L-carnosine in one step by using L-amino acid ligase, and belongs to the field of biotechnology. Background technique [0002] L-carnosine (β-alanyl-L-histidine) and its analogues (such as homocarnosine and anserine) are natural active dipeptides widely present in the brain, muscle and other important tissues of mammals. Since the discovery of this active peptide for more than 100 years, a large number of studies have found or proved that L-carnosine has significant anti-oxidation, elimination of intracellular free radicals, anti-aging and other activities, and it is clinically used for hypertension, heart disease, etc. adjuvant therapy for disease, senile cataract, ulcer, anti-tumor, and promotion of wound healing. Due to its strong antioxidant activity, low toxic and side effects and various physiological activities, the active peptide and its de...

AI Technical Summary

Problems solved by technology

This method still needs to methylate β-alanine, and the L-carnosine synthesized in the reaction solution will be degraded into β-alanine and L-histidine by aminopeptidase, and at the same time, aminopeptidase will form tripeptide , leading to complex reaction products and difficult extraction and purification

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