Bovine brain factor promotes neurite extension from chick embryo dorsal root ganglia in vitro.

A protein with neurite-stimulating activity was isolated from bovine brain tissue lysosomal fraction. The organotypic culture of dorsal root ganglia (DRG) of 10-11-day-old chick embryo was used to test neurite-stimulating activity. A cation protein (16,000 Da) has been purified using a combination of extraction of acid-soluble proteins, preparative electrophoresis, and affinity chromatography on heparin-sepharose. This protein is active at 2-4 ng/ml inducing extensive neurite outgrowth in this bioassay compared to the control one. Many properties distinguish this factor from other known neuronotrophic factors.