Purification of type E botulinum neurotoxin by high-performance ion exchange chromatography

A purification procedure for type E botulinum neurotoxin has been developed, based solely on high-performance ion exchange chromatography. The method exploits the differential chromatographic behavior of the free neurotoxin versus the neurotoxin-protein 12S complex. The high purity of the product was demonstrated with sodium dodecyl sulfate-gel electrophoresis and amino acid sequencing. Beginning with dialyzed crude extract, at least 4 mg of pure neurotoxin could be obtained in two working days. The method has been adapted to user-prepared columns for processing large volumes of crude neurotoxin in one batch.