Further purification of a fibroblast growth factor-like factor from chick embryo extract by heparin-affinity chromatography.

A mitogenic factor which promotes quail myoblast proliferation has been purified some 10(5)-fold from chick embryo extract by a combination of cation-exchange chromatography and heparin-affinity chromatography. The factor is eluted from heparin-Sepharose with 2 M NaCl and is a single-chain polypeptide with an apparent molecular weight of 15,000 to 17,000. It is active at subnanogram level in triggering the proliferation and thereby delaying temporarily fusion of myoblasts. It also stimulates the proliferation of quail fibroblasts in a similar effective concentration range. For both myoblasts and fibroblasts the dose-response to the factor is quantitatively and qualitatively comparable with that of bovine pituitary fibroblast growth factor. These observations strongly suggest that the factor very probably corresponds to chicken fibroblast growth factor or to a closely related molecule(s) and that it is possibly involved in the regulation of myogenesis.