PubMed HealthSearch

Biomedical subjects

P E Schad

Publications and source records attributed to P E Schad.

2 recordsLinked to original sources

Inhibition of blood coagulation factor XIIIa-mediated cross-linking between fibronectin and collagen by polyamines.

Soluble fibronectin is found in body fluids and media of cultured adherent cells. Insoluble fibronectin is found in tissue stroma and in extracellular matrices of cultured cells. Fibronectin is a substrate for factor XIIIa (plasma transglutaminase) and can be cross-linked to collagen and to the alpha chain of fibrin. We have used sodium dodecyl sulfate-polyacrylamide gel electrophoresis to investigate the possibility that factor XIIIa-mediated cross-linking is influenced by polyamines. Spermidine inhibited cross-linking between fibronectin and type I collagen, isolated alpha 1 (I) collagen chains, or iodinated cyanogen bromide fragment 7 of alpha 1 (I) chains (125I-alpha 1 (I)-CB7). Half-maximal inhibition of cross-linking between 125I-alpha (I)-CB7 and fibronectin was observed when 0.1 mM spermine or spermidine was present. Spermidine, 0.7 mM, partially inhibited cross-linking between fibronectin and the alpha chain of fibrin but failed to inhibit cross-linking between the fibrin monomers of a fibrin clot. Spermidine also failed to inhibit cross-linking between fibronectin molecules when aggregation of fibronectin was induced with dithiothreitol. In contrast, 0.7 mM monodanyslcadaverine inhibited fibronectin-collagen, fibronectin-fibrin, fibronectin-fibronectin, and fibrin-fibrin cross-linking. Spermidine or spermine, 0.7 mM, enhanced the cross-linking between molecules of partially amidinated fibronectin, suggesting that N1,8-(di-gamma-glutamyl)-polyamine cross-linkages were formed. Spermidine and spermine failed to enhance cross-linking between monomers of amidinated fibrin. These results indicate that physiologic concentrations of polyamines specifically disturb transglutaminase-catalyzed cross-linking between fibronectin and collagen.

Animals

Cross-linking of fibronectin to collagen by blood coagulation Factor XIIIa.

Soluble fibronectin is found in body fluids and media of adherent cultured cells and binds to fibrin and collagen. Insoluble fibronectin is found in tissue stroma and in extracellular matrices of cultured cells. Fibronectin is a substrate for Factor XIIIa (plasma transglutaminase) and can be cross-linked by Factor XIIIa to itself and the the alpha-chain of fibrin. We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis to investigate Factor XIIIa-mediated crosslinking of fibronectin to collagen. At O degrees or 37 degrees C, fibronectin could be cross-linked to iodinated cyanogen bromide fragment 7 of the alpha 1(I) chain. At 22 degrees or 37 degrees C, fibronectin could be cross-linked to isolated alpha 1(I) chains of type I collagen. Fibronectin could also be crosslinked to types I and III collagen, but only at 37 degrees C. alpha 1(I)-CB7, alpha 1(I) collagen chains, type I collagen, type III collagen, and fibrin all blocked cross-linking between 125I-alpha 1 (I)-CB7 and fibronectin. alpha 1(I)-CB7 blocked cross-linking between fibronectin and fibrin. These results indicate that the determinants of fibronectin-fibrin and fibronectin-collagen binding and cross-linking are similar. Cross-linking of fibronectin to collagen likely occurs in vivo and may be important for normal wound healing, collagen fibrillogenesis, and embryogenesis.

Binding Sites