Hydrolysis of cholinesterase inhibitors using parathion hydrolase

摘要

A gene is provided encoding a DNA sequence for the expression of parathion hydrolase and a methionine analog thereof. In a preferred embodiment, a parathion hydrolase gene encoding sequence is obtained in which twenty-eight amino acids are deleted from the N-terminal amino acid sequence of parathion hydrolase. Parathion hydrolase or its analog is produced by transforming a host microorganism such as Escherichia, Bacillus or Streptomyces with the gene, culturing the microorganism in a culture medium and purifying parathion hydrolase therefrom. Highly purified soluble parathion hydrolase is produced by a purification method without using detergents such as Triton X-100 and Tween 20. Parathion hydrolase of enhanced activity is produced by adding cobalt or zinc or a mixture thereof to the culture medium in which the host microorganism is cultured. The parathion hydrolase is useful for hydrolyzing organophosphorus compounds such as the cholinesterase inhibitors, diisopropylphosphoro-fluoridate, pinacolylmethylphosphono- fluoridate and isopropylmethylphosphono-fluoridate.