Engineering enzymes having altered substrate specificity

摘要

A method for altering the substrate specificity of an enzyme comprises: (a) introducing DNA containing a copy of the enzyme-encoding gene into E. coli XL1 Red; (b) incubating the transformants to generate mutations in the gene; (c) reintroducing the mutated DNA into a microorganism (especially not exhibiting inhibiting activity e.g. a microorganism that does not express the enzyme endogenously); (d) incubating the microorganism on or in at least one selection medium containing at least one substrate that allows altered substrate specificity to be detected and which optionally contains other indicator substances; and (e) selecting colonies that exhibit an alteration in substrate specificity.