title: Expression, characterization of a novel nitrilase PpL19 from Pseudomonas psychrotolerans with S-selectivity toward mandelonitrile present in active inclusion bodies.
abstract: OBJECTIVE
  To identify a novel nitrilase with S-selectivity toward mandelonitrile that can produce (S)-mandelic acid in one step.
  
  
  RESULTS
  A novel nitrilase PpL19 from Pseudomonas psychrotolerans L19 was discovered by genome mining. It showed S-selectivity with an enantiomeric excess of 52.7 % when used to hydrolyse (R, S)-mandelonitrile. No byproduct was observed. PpL19 was overexpressed in Escherichia coli BL21 (DE3) and formed inclusion bodies that were active toward mandelonitrile and stable across a broad range of temperature and pH. In addition, PpL19 hydrolysed nitriles with diverse structures; arylacetonitriles were the optimal substrates. Homology modelling and docking studies of both enantiomers of mandelonitrile in the active site of nitrilase PpL19 shed light on the enantioselectivity.
  
  
  CONCLUSIONS
  A novel nitrilase PpL19 from P. psychrotolerans L19 was mined and distinguished from other nitrilases as it was expressed as an active inclusion body and showed S-selectivity toward mandelonitrile.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China. hlwang@ecust.edu.cn.
authors.forename: Hualei
authors.identifier: http://orcid.org/0000-0002-0111-753X
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
authors.forename: Dongzhi
authors.initials: D
authors.lastname: Wei
mesh_terms: D000097:Acetonitriles / Q000378:metabolism*; D000619:Aminohydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D002479:Inclusion Bodies / Q000201:enzymology; D008333:Mandelic Acids / Q000378:metabolism*; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D011549:Pseudomonas / Q000201:enzymology* / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000097:Acetonitriles; D008333:Mandelic Acids; D011994:Recombinant Proteins; C045516:mandelonitrile; D000619:Aminohydrolases; C021867:nitrilase; C037938:mandelic acid
keywords: (S)-Mandelic acid; Active inclusion body; Mandelonitrile; Nitrilase; Pseudomonas psychrotolerans L19