Isolation And Characterization Of The Nerve Growth Factor From The Venom Of Vipera Russelli Siamensis Smith

Venom is one of the sources to extract nerve growth factor (NGF). In this study, NGF was purified from the venom of Vipera russelli siamensis by CM52, DEAE Sephadex A - 50 and Sephadex G - 75 column chromatography. The biological activity of NGF fraction is identified by the neurite outgrowth on PC12 cells which in the presence of active NGF. The NGF proved to be homogeneous by polyacrylamide gel electrophoresis(PAGE) and isoelectric focusing in PAGE(EFG). On SDS-PAGE, the purified NGF migrated with two different subunits. So the purified NGF is a bi-chain structure that is consisted of two different polypeptide chains. The chains are linked to each other by a disulphide bond. The molecular weight was measured to be 36KD by SDS-PAGE. The isoelectric point of NGF is 6.7. It is consisted of two polypeptide chains which are different.Animal models of the injured sciatic nerve were established in SD rats. The agar with venom NGF could be embedded in the crushed sciatic nerve. The toe-spreading reflex(TSR) and the pain threshold were investigated to observe the effects of NGF on the functional recovery of sciatic nerve following crush injury. Tarlov function value is adopted for injured sciatic nerve as well. The sciatic nerve of the rats in the TSR and the pain threshold of NGF groups were recovered much better than that in the group without NGF. It shows the venom NGF can significantly enhances the recovery of functions of the injured nerve.