Patent ID: 9347047
Filing Date: 2016-05-24
CPC Classification: C07K,C12N,C12P,C12Q,C12Y,G01N

Claim Text:
1. A modified leucine dehydrogenase enzyme comprising at least one amino acid mutation as compared to a non-modified leucine dehydrogenase enzyme, wherein said modified leucine dehydrogenase is improved in one or more properties selected from the group consisting of: (a) substrate specificities for L-leucine, L-isoleucine, and L-valine; (b) activity for any branched-chain amino acid; (c) thermal stability, and (d) combinations thereof, wherein said modified leucine dehydrogenase is: (A) a protein comprising the amino acid sequence of SEQ ID NO: 2; but having a substitution of isoleucine in the TGI motif with an amino acid selected from the group consisting of methionine, arginine, histidine, phenylalanine, leucine, lysine, cysteine, tyrosine, alanine, glycine, serine, asparagine, and tryptophan, (B) a protein comprising the amino acid sequence of SEQ ID NO: 2; but having a substitution of isoleucine in the GVI motif with an amino acid selected from the group consisting of phenylalanine, histidine, asparagine, tyrosine, leucine, lysine, glutamine, arginine, aspartic acid, threonine, glutamic acid, serine, cysteine, alanine, glycine, valine, tryptophan, and methionine, (C) a protein comprising the amino acid sequence of SEQ ID NO: 2; but having a substitution of isoleucine in the TGI motif with an amino acid selected from the group consisting of methionine, arginine, histidine, phenylalanine, leucine, lysine, cysteine, tyrosine, alanine, glycine, serine, asparagine, and tryptophan; and a substitution of isoleucine in the GVI motif with an amino acid selected from the group consisting of phenylalanine, histidine, asparagine, tyrosine, leucine, lysine, glutamine, arginine, aspartic acid, threonine, glutamic acid, serine, cysteine, alanine, glycine, valine, tryptophan, and methionine, and (D) a protein as described in (A), (B), or (C) above, but also having one to ten additional mutations of amino acid residues.