Thermostable, salt tolerant, wide PH range novel chitobiase

摘要

A cloned chitobiase from a Vibrio parahemolyticus gene cloned into the plasmid pUC18 in E. coli strain DH5&agr;. The plasmid construct, called pC120, had a 604 kb DNA insert. The recombinant gene expressed chitobiase activity similar to that found in native V. parahemolyticus. In addition to chitobiose, at least six additional substrates were observed to be hydrolyzed by the recombinant chitobiase, including &bgr;- N-acetyl galactosamine glycosides, showing that the enzyme is an N-acetyl- hexosaminidase. The enzyme showed resistance to denaturation by 2M NaCl, was thermostable at 45° C., and possessed an unusual range of activity from pH 5 to 9. The enzyme is useful in the degradation of crustacean shells. It catalyzes the production of N-acetyl-glucosamine, a compound which should be valuable as a chiral precursor or intermediate in the synthesis or manufacture of pharmaceutical compounds.