GO:0005604; C:basement membrane; IEA:Compara. GO:0005506; F:iron ion binding; IEA:InterPro. GO:0031418; F:L-ascorbic acid binding; IEA:InterPro. GO:0016706; F:oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, 2-oxoglutarate as one donor, and incorporation of one atom each of oxygen into both donors; IEA:InterPro.