Improved purification of an (R)-oxynitrilase from Linum usitatissimum (flax) and investigation of the substrate range.
The purification of (R)-oxynitrilase (EC 4.1.2.10) from Linum usitatissimum (flax) has been improved considerably. The enzyme is obtained from seedlings in 60% yield by fractional salt precipitation followed by ion-exchange and hydrophobic-interaction chromatography. Final gel-permeation chromatography yields a protein with a specific activity of 53 units/mg at pH 4.1. The N-terminal sequence is reported and microheterogeneity demonstrated. The substrate range was investigated using (R)-oxynitrilase immobilized on Eupergit and t-butyl methyl ether as solvent. The addition of HCN to various aliphatic ketones and aldehydes is catalysed by the enzyme, while aromatic ketones are not converted. (R)-Butan-2-one cyanohydrin was synthesized on a preparative scale and the product characterized.
Institut für Enzymtechnologie der Heinrich-Heine-Universität Düsseldorf, Federal Republic of Germany.
J
J
Albrecht
I
I
Jansen
M R
MR
Kula
D000446:Aldehyde-Lyases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D000595:Amino Acid Sequence; D004795:Enzyme Stability; D006856:Hydrogen Cyanide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007659:Ketones / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009570:Nitriles / Q000138:chemical synthesis; D010944:Plants / Q000201:enzymology*; D013379:Substrate Specificity
D007659:Ketones; D009570:Nitriles; D006856:Hydrogen Cyanide; C081147:2-hydroxy-2-methylbutanenitrile; D000446:Aldehyde-Lyases; C021541:mandelonitrile lyase