The invention relates to the technical field of the preparation for alanyl-
glutamine dipeptide and particularly discloses a method for preparing alanyl-
glutamine dipeptide through biological
enzyme conversion. The method comprises the following steps: 1) preparing a biological
enzyme liquid: dissolving the biological
enzyme in a buffered liquid, controlling pH value within the scope of 7.0+ / -2.0, controlling the temperature at 5-10 DEG C, thereby acquiring the biological enzyme liquid, wherein the
mass fraction of the ester acyl-containing transferring biological enzyme is 5%-20%; 2) dissolving the ester derivates of substrate L-
alanine and
glutamine in pure water, and then uniformly dropping the biological enzyme liquid into a reaction liquor, and meanwhile, adding acid liquor or alkali liquor, controlling the pH of the reaction liquor at 5-10, reacting under the temperature controlled at 15-25 DEG C, sampling and detecting the production of the alanyl-glutamine
dipeptide during the reaction process, stopping reaction when the content of the alanyl-glutamine dipeptide is highest, and separating the acquired converted liquid, thereby acquiring the alanyl-glutamine dipeptide. According to the method provided by the invention, the enzyme activity is high, the
reaction rate of the materials is higher, the method has the advantages of simple technique control, easy control on quality index and low cost, and the method is more fit for industrial production.