(115p) Degradation of Chlorinated Organic Pollutants Using An Immobilized Thermostable Dehalogenase

Extremely stable enzymes isolated from extremophiles have found many applications in biotechnology. We have developed a convenient expression and purification procedure for the production of a highly stable L-2-haloacid dehalogenase, which we named L-HAD_ST, from the thermophile Sulfolobus tokodaii. The high expression yield and easy purification procedure make the recombinant dehalogenase an excellent candidate for biotechnology applications. In the current study, we covalently attached L-HAD_ST to N-hydroxysuccinimidyl (NHS)-Sepharose resins through the coupling between the NHS-activated carboxyl groups on Sepharose and free amines in the protein. We demonstrated that the immobilized protein was catalytically active, retaining 90% specific activity of the free protein. The functionalized resins can be simply washed and reused multiple times. We performed the catalysis/regeneration cycle several times and found that the resins maintained full catalytic activity throughout the procedure. Our results indicate that the immobilized thermostable dehalogenase could be useful in the dehalogenation of organic pollutants in liquid samples.