Isolation and characteristics of a nerve growth factor from the venom of the Central Asiatic viper Echis multisquamatus

The nerve growth factor (NGF) was isolated from the Echis multisquamatus venom by ultrafiltration on PM-10 filter, chromatography on TSK-55 gel, ion-exchange chromatography on CM-cellulose and gel filtration on Sephadex G-75. The protein exhibited a marked nerve growth activity within the concentration range of 10-15 ng/ml in cultures of chicken embryo spinal ganglia. The molecular mass of NGF is equal to 33,000-37,000 Da according to Sephadex G-75 gel filtration data; however, according to SDS electrophoresis data its Mr is 13,000 Da. Isoelectrofocusing data suggest that the pI of the isolated factor lies in the region of 7.0-7.2; sugar content is 1-2%.