Nerve growth factor is important for the development and maintenance of the sympathetic and sensory nervous systems. It stimulates division and differentiation of sympathetic and embryonic sensory neurons as well as basal forebrain cholinergic neurons in the brain. Its relevance in the snake venom is not clear. However, it has been shown to inhibit metalloproteinase-dependent proteolysis of platelet glycoprotein Ib alpha, suggesting a metalloproteinase inhibition to prevent metalloprotease autodigestion and/or protection against prey proteases. Binds a lipid between the two protein chains in the homodimer. The lipid-bound form promotes histamine relase from mouse mast cells, contrary to the lipid-free form 