L(+)-2-Aminobutyric acid is to suppress the natural amino acid that human nerve information is transmitted, and also is a kind of important chemical material and medicine intermediate, and it is synthetic to be widely used in medicine, for example synthetic of Levetiracetam. N-haloamines also containing a hydroxy group, a sulfonic acid group, and N-acyl group or a carboxylic acid group are useful in treating teeth to remove caries, dissolve or remove plaque, to help in the prevention of calculus formation and in the brightening of teeth.

Biocatalytic Synthesis

A technical scheme of the invention is that: the method for preparing the L-2-aminobutyric acid by the enzyme method is characterized by comprising the following steps of: converting L-threonine which is taken as a starting material into 2-ketobutyrate by using threonine deaminase; and then converting the 2-ketobutyrate into the L-2-aminobutyric acid by using leucine dehydrogenase, and adding hydrogenlyase used for coenzyme generation in the reaction. 

In the 5ml reaction flask, add 20mg L-Threonine successively, 32mg ammonium formiate (about 2.5 times of equivalents), 0.2mgNAD +And 2ml phosphate buffered saline buffer (Na 2HPO 4/ NaH 2PO 4, 0.1M, pH 7.5), with strong aqua the pH value of solution value is transferred to 7.5, add the thick enzyme of 1mg threonine deaminase again, thick enzyme of 2mg leucine dehydrogenase and the thick enzyme of 2mg hydrogenlyase, after 3 hours, sampling is carried out HPLC and is analyzed transformation efficiency＞95% (C18 post at 25 ℃ of lower magnetic force stirring reactions; UV 200nm detects; Moving phase: 20mM phosphate buffered saline buffer (pH 3.0)/acetonitrile=95/5, v/v), ee value＞99% (CR (+) post; UV 200nm detects; Moving phase: high chloro acid solution (pH 1.5)).