Purification and characterization of nerve growth factor from the venom of Bungarus multicinctus.

The nerve growth factor from Bungarus multicinctus venom was purified by means of successive chromatography on Sephadex G-50, carboxymethyl-cellulose, carboxymethyl-Sephadex C-50 and Sephadex G-50. The purified nerve growth factor was homogeneous by polyacrylamide disc gel electrophoresis. The molecular weight was estimated to be about 21 000 by gel filtration. Compared with the nerve growth factors from the venoms of other Elapidae, namely Naja naja and Naja naja atra, this protein showed high isoelectric point of approximately pH 10. A characteristic of the nerve growth factor of B. multicinctus venom is that the protein consisted of two subunits of equal molecular weight which are linked covalently to each other by a disulfide bridge. The purified B. multicintus nerve growth factor elicited its maximal neurite outgrowth from embryonic dorsal root ganglia at the concentration interval from 30 to 100 ng/ml.