Aminopeptidases pseudomonas putida

L-Amino adds could be produced from D,L-aminonitriles with 50% conversion using Pseudomonas putida and Brembacterium sp respectively, the remainder being the corresponding D-amino add amide. However, this does not prove the presence of a stereoselective nitrilase. It is more likely that the nitrile hydratase converts the D,L-nitrile into the D,L-amino add amide, where upon a L-spedfic amidase converts the amide further into 50% L-amino add and 50% D-amino add amide. In this respect the method has no real advantage over the process of using a stereospecific L-aminopeptidase (vide supra). 

The aminopeptidase from Pseudomonas putida ATCC 12633 has also recently been cloned and overexpressed in E. coli resulting in a highly efficient whole-cell biocatalyst for industrial applications 1291. The specific activity of this new biocatalyst is substantially increased (25 times) compared with the specific activity of the P. putida wild type cells without changing the other positive characteristics of the aminopeptidase. Even though the aminopeptidase from Pseudomonas putida exhibits the relaxed substrate specificity described above, an a-hydrogen atom in the substrate is an essential structural feature for the enzymatic activity. Therefore this enzyme can not be used for the resolution of higher substituted amino acids. 

Kinetic Resolution of a-Amino Acid Amides Catalyzed by Aminopeptidase from Pseudomonas putida (E.C. 3.4.1.11) [72 751... 

E = aminopeptidase, whole cells from Pseudomonas putida... 

L-a-Amino acids have been prepared by the resolution of racemic a-amino acid amide by the L-specific aminopeptidase from Pseudomonas putida ATCC 12633 [7]. Enzyme from R putida ATCC 12633 cannot be used to resolve a-alkyl-substituted amino acid amides 103. Aminoamidase from Mycobacterium neoaurum ATCC 25795 has been used in the preparation of L-a-alkyl amino acid 104 (Fig. 34) and D-amide of a-alkyl-substituted amino acids by enzjmaatic resolution process using racemic a-alkyl amino acid amide as a substrate [169,179]. Amidase from Ochrobactrum anthropi catalyzed the resolution of a,a-disubsituted amino acids, iV-hydroxy amino acids, and a-hydroxy acid amides. The resolution process could lead to the production of chiral amino acids or amides in 50% yield. Recently, amino acid racemases have been used to get 100% yield of chiral amino acids [179]. 

---