Halohydrin dehalogenase

[4] The ability to dehalogenate organic compounds as well as form enantiomeric selective epoxides have generated interest in the potential of this enzyme in the biochemical field.

[3] The serine and tyrosine residues function to stabilize the substrate and its intermediate, while the arginine alters the pKa of Tyr145 to make it catalytically active.

[8] Halohydrin dehalogenases mechanistically cleaves the carbon-halogen bond through the formation of an epoxide from a vicinal hydroxyl group.

[8][3] The substrate binds to the active site through hydrogen bonding that is coordinated by Ser132 and the deprotonated form of Tyr145.

[9][10] However, the preference for the formation of the (R)-epoxide isomer catalyzed by enzymes in class C, particularly HHeC, is high.