Propolypeptide of von Willebrand factor serves as a substrate for factor XIIIa and is cross-linked to laminin.
The propolypeptide of von Willebrand factor (pp-vWF) was found to serve as a substrate for Factor XIIIa (FXIIIa). FXIIIa catalyzed polymerization of pp-vWF as well as the incorporation of monodansylcadaverine and [14C]putrescine into pp-vWF in a Ca(2+)- and time-dependent manner. The amount of putrescine incorporated into pp-vWF was increased as a function of putrescine concentration and reached a maximum of 3 mol/mol of pp-vWF, indicating that there are at least 3 glutamine residues in the pp-vWF molecule responsible for the reaction. 125I-pp-vWF was incubated with FXIIIa in the presence of various adhesive glycoproteins. Laminin, among the proteins tested, specifically formed a large molecular weight complex with 125I-pp-vWF in a Ca(2+)- and time-dependent manner. It was also found that FXIIIa catalyzed polymerization of laminin as well as the incorporation of monodansylca-daverine into laminin. The high molecular weight complexes of 125I-pp-vWF (or 125I-laminin) formed in the presence of laminin (or pp-vWF) were immunoprecipitated with anti-laminin (or anti-pp-vWF) antibodies. Taking all the data together it can be concluded that both pp-vWF and laminin have glutamine and lysine residues responsive to FXIIIa and make copolymers by virtue of FXIIIa.
Usui
T
T
Department of Biological Sciences, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan.
Takagi
J
J
Saito
Y
Y
D000818:Animals; D000911:Antibodies, Monoclonal; D002417:Cattle; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007700:Kinetics; D007797:Laminin / Q000302:isolation & purification / Q000378:metabolism*; D046911:Macromolecular Substances; D051379:Mice; D011498:Protein Precursors / Q000302:isolation & purification / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism; D013379:Substrate Specificity; D013917:Thrombin / Q000378:metabolism; D011503:Transglutaminases / Q000378:metabolism*; D014841:von Willebrand Factor / Q000302:isolation & purification / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D007797:Laminin; D046911:Macromolecular Substances; D011498:Protein Precursors; D014841:von Willebrand Factor; C067003:von Willebrand factor propolypeptide; D011503:Transglutaminases; D013917:Thrombin; D011700:Putrescine