THE NERVE GROWTH FACTOR: PURIFICATION AS A 30,000-MOLECULAR-WEIGHT PROTEIN

TLDR

The nerve growth factor was purified from adult mouse salivary glands by gel filtration on Sephadex G‑100 at pH 7.5, followed by dialysis at pH 5 and CM52 cellulose chromatography at pH 5, yielding a 30,000‑Da protein. The purified protein was homogeneous, had a Stokes radius of 2.43 nm, a diffusion coefficient of 7.30 × 10⁻¹⁰ m²/s, a molecular weight of 30,000 Da, and an overall recovery of about 45 %.

Abstract

The nerve growth factor protein was purified over 100-fold from adult mouse salivary glands. The first step was a gel filtration on Sephadex G-100 at pH 7.5 of the aqueous gland extract. After gel filtration, most of the NGF activity was eluted in the 80,000-90,000-molecular-weight region (G-100 pool). The G-100 pool was dialyzed at pH 5.0 and fractionated by CM52 cellulose chromatography at pH 5.0. Recovery from CM52 cellulose columns was quantitative for protein and ranged 80-100 per cent for the nerve growth factor activity; the latter was almost completely carried by a protein which did not show any heterogeneity when examined by several analytical tests. The purified nerve growth factor showed an S 20, w = 2.43, a D 20, w = 7.30 and a 30,000 molecular weight. The over-all recovery was about 45 per cent.