Nerve growth factor activity of several immunal related serine proteases

Rabbit was immuned by the previously purified protein with high nerve growt h factor (NGF) bioactivity (NGF-like protease) from Agkistrodon halys Palla s and the antisera were collected. The polyclonal antibodies were tentative ly purified and then used as ligands of an affinity column. The A. h. Palla s crude venom was fractionated by this affinity column and then by Mono Q o n fast protein liquid chromatography (FPLC). As a result, fraction II and f raction III were purified respectively, whose N-terminal amino acid sequenc es show high homology with the serine proteases in snake venoms, as well as the previous NGF-like protease. However, they possessed different levels o f NGF bioactivity. The NGF activity of the previous NGF-like protease is eq uivalent to that of NGF, while the activity of fraction II seems relatively low in contrast to fraction III which had no NGF activity.