The glioma cell-derived neurite promoting activity protein is functionally and immunologically related to human protease nexin-I.
Protease nexin-I (PN-I, Mr approximately 43,000) is representative of a newly described class of cell-secreted protease inhibitors. PN-I has been purified to apparent homogeneity, partially sequenced, and monospecific antibodies have been raised against it. PN-I is a potent inhibitor of urokinase, thrombin, plasmin, and trypsin. In addition, cells have specific receptors that mediate the uptake of covalently linked complexes formed between PN-I and its protease substrates. In the present studies, we have investigated the relationship between human PN-I and a protease inhibitor derived from C6 glioma cells in culture that has neurite-promoting activity. On the basis of co-purification on heparin-Sepharose, identical molecular weight, antibody cross-reactivity, and receptor cross-reactivity, we conclude that PN-I and the glioma-cell-derived inhibitor are equivalent molecules.
D016564:Amyloid beta-Protein Precursor; D000818:Animals; D000941:Antigens / Q000276:immunology; D001369:Axons; D002352:Carrier Proteins / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology*; D002460:Cell Line; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D007163:Immunosorbent Techniques; D008970:Molecular Weight; D058255:Protease Nexins; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
D016564:Amyloid beta-Protein Precursor; D000941:Antigens; D002352:Carrier Proteins; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D014568:Urokinase-Type Plasminogen Activator