PURPOSE: To obtain the subject protein showing binding activity to heparin- bondable growth factor, useful as a therapeutic agent for diseases of neurological function, osteoplastic ability, etc., controlling action of the binding activity, having a specific amino end sequence, derived from an animal brain.

CONSTITUTION: A brain of a young rat 14 days after birth is collected, ground in a buffer solution for grinding tissue by a homogenizer and the ground solution is centrifuged to give a centrifuged substance. The centrifuged substance is solubilized with a solubilizing buffer solution and centrifuged to collect its supernatant liquid. The supernatant liquid is applied to a heparin sepharose column, the adsorbed substance is eluted by a linear gradient using 0.5-2.5M NaCl-containing buffer solution, the eluate is purified by an ion exchange column chromatography method, the eluted fraction is purified by a reversed phase column chromatography method to give the objective new protein having about 200KDa molecular weight by analysis with SDS-PAGE under a reducing condition, an amino end sequence with an amino end sequence of the formula and integrity with a heparin bondable growth factor.