PROTEIN FOR CHEMOENZYMATIC PRODUCTION OF L-THREO-HYDROXYASPARTATE

摘要

The present invention describes a simple mutant of natural asparagine oxygenase, wherein said simple mutant comprises at least the amino acids 13 through 318 of the natural asparagine oxygenase AsnO. In said protein according to the invention comprising at least the amino acids 13-318 from AsnO D241 N, the residual amino acid at position 241 of the natural asparagine oxygenase AsnO is exchanged from aspartate (D) to asparagine (N). The protein according to the invention comprising at least the amino acids 13-318 of AsnO D241 N is produced by a directed mutagenesis of the AsnO wild type, cloning of the expression plasmid into a vector, transformation of the vector plasmid construct into a host organism, and expression of the recombinant protein. The protein according to the invention is suitable for chemoenzymatic and enantioselective production of L-threo-hydroxyaspartate from L-aspartate. The protein is substrate specific, and quantitatively converts L-aspartate to L-threohydroxyaspartate.