Purification and characterization of a highly selective epoxide hydrolase from Nocardia sp. EH1.
A highly enantioselective, soluble epoxide from Nocardia sp. EH1 was purified to homogeneity via a four-step procedure: (i) hydrophobic interaction chromatography on Phenyl Sepharose CL-4B, (ii) anion exchange chromatography on SOURCE 30Q, followed by (iii) a second hydrophobic interaction chromatography on Phenyl Sepharose HP, and finally (iv) gel-filtration on Superdex 75 HR 10/30. The pure protein was shown to be a monomer of integral of 34 kDa possessing an optimum pH of 8-9. Neither UV-absorbing cofactors nor metal ions were required for activity. In contrast to whole-cell activity, the partially purified enzyme proved to be considerably less stable. Stabilization was achieved by addition of non-ionic detergents such as Tween 80 or Triton X-100, causing a shift of the temperature optimum from 35 to 40 degrees C. Both effects combined led to an enhancement of the relative activity of up to approximately 150% of that of the native enzyme.
Kroutil
W
W
Institute of Organic Chemistry, Graz University of Technology, Austria.
Genzel
Y
Y
Pietzsch
M
M
Syldatk
C
C
Faber
K
K
D001709:Biotechnology; D003902:Detergents; D004795:Enzyme Stability; D004851:Epoxide Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009615:Nocardia / Q000201:enzymology*; D012492:Salts; D013696:Temperature
D003902:Detergents; D012492:Salts; D004851:Epoxide Hydrolases