Enzymatic Detoxification of Chemical Warfare Agents: Immobilization of the Enzyme for Material Surfaces

The objective of this research is to investigate feasibility of immobilizing squid-type DFPase on fabrics such as nylon, polyester, cotton and polyester-cotton blends and on polyethylene glycol. Large quantities about 15, 000 units on of the enzyme was prepared from the hepatopancreas tissues of East Coast ECHP and West Coast WCHP squid belonging to the species, Loligo Pealii and Loligo Opalescens. The purified enzyme preparations were characterized by their activities against diisopropylphosphorofluoridate DFP, isopropylmethylphosphonofluoridate SARIN and pinacolylmethyl phosphonofluoridate SOMAN and their kinetic constants KM and VMAX. The enzyme-immobilization study included the exploration of different preactivation methods involving treatment with 1 glutaraldehyde, 2 triethyloxoniumtetrafluoroborate TTFB, 3 tresylchloride, 4 isocyanide, 5 cyanuric chloride and 6 KMnO4-oxidation. Results of examination of the DFPase- immobilized matrices showed agent-specific activities DFP, SOMAN and SARIN in the range 3.5 to 17.7 unitsgram. A number of them retained up to 90 of their initial enzyme activity over a 90-day period. This is indicative of a good potential for this technical approach squid-type DFPase.