Insights into pathological mechanisms of missense mutations in C-terminal domains of von Willebrand factor causing qualitative or quantitative von Willebrand disease.

摘要: The carboxyl-terminal domains of von Willebrand factor, D4-CK, are cysteine-rich implying that they structurally important. In this study we characterized the impact five cysteine missense mutations residing in D4-CK on conformation and biosynthesis factor. These variants were identified as heterozygous type 1 (p.Cys2619Tyr p.Cys2676Phe), 2A (p.Cys2085Tyr p.Cys2327Trp) compound 3 (p.Cys2283Arg) disease. Transient expression human cell lines with wild-type or mutant factor constructs was performed. mutated recombinant factors quantitatively qualitatively assessed compared. Storage pseudo-Weibel-Palade bodies studied confocal microscopy. structural analyzed by homology modeling. Homozygous expressions showed these caused defects multimerization, elongation secretion Co-expressions p.Cys2085Tyr, p.Cys2327Trp p.Cys2283Arg demonstrated defective multimer assembly, suggesting a new pathological mechanism for dominant disease due to D4 B domains. Structural analysis revealed p.Cys2283Arg, p.Cys2619Tyr p.Cys2676Phe disrupted intra-domain disulfide bonds, whereas might affect an inter-domain bond. variant is distinguished from other mutants electrophoretic mobility shift bands. results highlight importance residues within protein consequently storage,