Expansion of the Substrate Specificity of Porcine Kidney D-Amino Acid Oxidase for S-Stereoselective Oxidation of 4-Cl-Benzhydrylamine.
ChemCatChem
; 10(16): 3500-3505, 2018 Aug 21.
Article
in En
| MEDLINE
| ID: mdl-30333894
ABSTRACT
Discovery and development of enzymes for the synthesis of chiral amines have been a hot topic for basic and applied aspects of biocatalysts. Based on our X-ray crystallographic analyses of porcine kidney D-amino acid oxidase (pkDAO) and its variants, we rationally designed a new variant that catalyzed the oxidation of (S)-4-Cl-benzhydrylamine (CBHA) from pkDAO and obtained it by functional high-throughput screening with colorimetric assay. The variant I230A/R283G was constructed from the variant R283G which had completely lost the activity for D-amino acids, further gaining new activity toward (S)-chiral amines with the bulky substituents. The variant enzyme (I230A/R283G) was characterized to have a catalytic efficiency of 1.85â
s-1 for (S)-CBHA, while that for (R)-1-phenylethylamine was diminished 10-fold as compared with the Y228L/R283G variant. The variant was efficiently used for the synthesis of (R)-CBHA in 96 % ee from racemic CBHA by the deracemization reaction in the presence of reducing agent such as NaBH4 in water. Furthermore, X-ray crystallographic analysis of the new variant complexed with (S)-CBHA, together with modelling study clearly showed the basis of understanding the structure-activity relationship of pkDAO.
Full text:
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Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
ChemCatChem
Year:
2018
Document type:
Article