APPLICATION OF FREE-FLOW ELECTROPHORESIS TO THE PURIFICATION OF TRICHOSANTHIN FROM A CRUDE PRODUCT OF ACETONE FRACTIONAL PRECIPITATION

The application of free-flow electrophoresis (FFE) to the purification of trichosanthin (TCS) from a crude product of acetone fractional pre cipitation was investigated. An electrophoresis technique, combining f ield step electrophoresis (FSE) and zone electrophoresis (ZE) to a one -step procedure, was optimized until a satisfactory purification facto r (1.35), high resolution, and purity (>99%) were achieved. Testing se veral separation buffer systems revealed that a throughput of 14.2 mg/ h can be obtained when the very basic TCS (pI 10.1) was dissolved and electrophoresed in a phosphate buffer system of pH 4. The purity of el ectrophoresed trichosanthin was proved by a variety of analytical meth ods, such as sodium dodecyl sulfate (SDS)-gel electrophoresis, capilla ry isoelectric focusing (CIEF), and sequencing of N- and C-termini. Th e high purity and large throughput achieved at low cost by using FFE i ndicates that this method can be employed for TCS purification.