Purification form human hepatoma cells of a 130-kDa membrane glycoprotein with properties of the heparin-binding growth factor receptor.

The detergent-soluble 125I-labeled receptor complex resulting after affinity cross-linking of 125I-heparin-binding growth factor type one (HBGF-1, m = 15.2-kDa) to HepG2 cells had an apparent molecular mass of 145-kDa, eluted from immobilized wheat germ lectin in the presence of N-acetylglucosamine, shifted to apparent mass of 128-kDa when treated with N-glycanase and shifted to apparent mass of 205-kDa after reduction, carboxymethylation and succinylation. Electrophoretic analysis of HepG2 cell membrane proteins revealed a major silver-stained protein of apparent molecular mass of 130-kDa that has correlative properties. These properties were used to purify the 130-kDa HepG2 glycoprotein to apparent homogeneity and suggest the glycoprotein as a candidate for the human HBGF receptor.