Biological actions of 53 kDa nerve growth factor as studied by a blot and culture technique

A blot and culture technique has been utilized to examine the biological actions of 53,000 Dalton (53 kDa) nerve growth factor (NGF) present in the submaxillary gland (SMG) of adult male and female mice. SMG-proteins were first resolved by sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis (PAGE) under reducing conditions and then transferred to a nitrocellulose (NTC) sheet by electroblotting. Specific areas corresponding to 53 kDa NGF were cut and cultured with the rat pheochromocytoma cell line, PC-12. NTC strips bearing the 53 kDa NGF band stimulated cell flattening and neurite formation in serum containing growth medium and augmented cell survival in serum-free growth medium. Similar results were obtained with NTC strips bearing the 13 kDa NGF band. The results suggest that 53 kDa NGF, like 13 kDa NGF, exerts both tropic and trophic actions on its target neurons.