Purification of sciatin using affinity chromatography on concanavalin A-Agarose

A glycoprotein from chicken sciatic nerves, sciatin, has been shown to have trophic effects on the maturation and maintenance of skeletal muscle cells in culture. This protein was purified 24-fold from sciatic nerve extracts by affinity chromatography on concanavalin A-agarose followed by ion-exchange on diethylaminoethyl cellulose. The purity of sciatin obtained by this procedure was greater than 97% as estimated by densitometric integration of sodium dodecyl sulfate gels, and represented 33% of the sciatin present in sciatic nerve extracts as determined by rocket immunoelectrophoresis. Sciatin purified by this technique retained full biological activity since (1) addition of the protein to embryonic chicken skeletal muscle cells in culture enhanced the morphological development of the cells, and (2) the protein increased the number of acetylcholine receptors as measured by binding of 125I-alpha-bungarotoxin to 261% of the control value after 4 days in vitro. The purification procedure described in the present communication provides a more rapid and convenient method for the isolation of this trophic protein.