Purification of 5-enolpyruvylshikimate 3-phosphate synthase from Escherichia coli.

A procedure for the purification of 5-enolpyruvylshikimate 3-phosphate synthase from Escherichia coli is described. Homogeneous enzyme of specific activity 17.7 units/mg was obtained in 22% yield. The key purification step involves substrate elution of the enzyme from a cellulose phosphate column. The subunit Mr was estimated to be 49 000 by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. The native Mr was estimated to be 55 000 by gel filtration, indicating that the enzyme is monomeric.