A proteolytic 140-kDa fragment of neurite outgrowth factor and its cell-binding activity

A neurite outgrowth factor (NOF) from chicken gizzard was treated with elastase, and a protease-resistant fragment of 140 kDa (F-140) with heparin-binding activity, was isolated from the digested mixture. Although F-140 showed no neurite outgrowth activity, it could bind dissociated cells from the dorsal root ganglia of chick embryos. The antiserum to F-140 inhibited the cell binding activity of native NOF in a dose-dependent manner, but not the neurite outgrowth activity. When membrane proteins from whole chick embryos were incubated with NOF or F-140, a protein band of 41 kDa was detected as a major NOF-binding component.