Co-enzyme-independent L-sorbosone dehydrogenase of gluconobacter oxydans: isolation, characterization, and cloning and autologus expression of the gene

摘要

A novel coenzyme independent L-sorbosone dehydrogenase originating from a microorganism belonging to the genus Gluconobacter oxydans which acts on L-sorbosone to produce 2-keto-L-gulonic acid. PP The enzyme has the following physico-chemical properties:P Pa) optimum pH: about 7.0,PP b) optimum temperature: about 30° C. to about 40° C.,P Pc) molecular sturucture: consisting of one type of unit having a molecular weight of about 47,500.+-.5,000 as measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis,PPd) thermostability: stable below 30° C., andPPe) inhibition: by Cu.sup. 2+ -ions.