[The neurotrophic factor nerve growth factor (NGF) synthetized by murine L-929 cells is not associated with alpha and gamma subunits].

L-929 cells secrete a neurotrophic factor which is immunologically related to the beta NGF present in the male Mouse submaxillary gland. In order to determine whether L-929 cells also synthesize the alpha and gamma subunits which are associated with the beta NGF in the gland, immunoprecipitations were performed with appropriate antisera. Our results indicate the absence of alpha and gamma subunits in the extracellular medium or in the cell extracts and suggest that the synthesis and secretion of the beta NGF by the L cells does not require these two proteins.