Nerve growth factor: a protease that can activate plasminogen.

Abstract
The single, highly stable form of mouse submandibular gland nerve growth factor (NGF), prepared as described by Young et al. is a protease of restricted specificity that can convert plasminogen to plasmin. Without plasminogen, NGF was not fibrinolytic, nor did it hydrolyze casein at a measurable rate. Treatment of NGF with DFP inhibited its ability to activate plasminogen and its capacity to hydrolyze certain synthetic arginine esters. NGF is apparently a member of the class of serine proteases. Since NGF is secreted at high concentrations in mouse saliva, it may serve to activate plasminogen (with subsequent fibrinolysis) somewhere in the alimentary tract. Plasminogen activation is the only known action of NGF upon a biologically important non-neural substrate.