Matrix Gla Protein Binds to Fibronectin and Enhances Cell Attachment and Spreading on Fibronectin
MGP is incorporated into crosslinked fibronectin and fibrinogen by tissue transglutaminase. SDS-PAGE of reaction products of MGP, tTG, and extracellular matrix proteins. Lines indicate 7 marker positions of 200, 116, 97, 66, 43, 31, and 14 kDa. (a) Autoradiograph of 7.5% acrylamide SDS-PAGE gel the legend above indicates whether 125I-labeled MGP or tTG was present as + and − symbols; The protein incubated with MGP is shown in the top line, VN, vitronectin, FN, fibronectin, and FG, fibrinogen. MW indicates that molecular weight markers were run in those lanes. (b) Coomassie blue stained 7.5% acrylamide SDS-PAGE gel used for autoradiograph in (a). Molecular weight markers are 200, 116, 97, 66, 43, 31, and 14 kDa. MGP runs with the 14 kDa protein at the dye front on this gel. (c) Autoradiograph of 7.5% SDS-PAGE gel. The furthest right lane marked Ab+ shows inhibitory effect of added anti-MGP IgG on incorporation of MGP into crosslinked fibronectin.