Cobalt Activation of Bacillus BR449 Thermostable Nitrile Hydratase Expressed in Escherichia coli

摘要

Expression of nitrile hydratase enzymes utilized in a new " green " process for acrylamide production has proven difficult in Escherichia coli owing to lack of a cobalt transport system to introduce the required cobalt ion into this host. We describe the expression of a thermostable nitrile hydratase from a moderate thermophile B,acillus sp. BR449 inE. coliin which the cobalt required for enzyme activation is introduced by incubation of the apoenzyme in the presence of Co++ ion at 50°C, yielding active and thermostable enzyme.