title: Structure and function of a recombinant von Willebrand factor drug candidate.
abstract: The complex structure, large size, and multiple posttranslational modifications of von Willebrand factor (VWF) presented a technological challenge for the production of recombinant VWF (rVWF). Nonetheless, we developed an rVWF product for treating von Willebrand disease, whereupon rVWF is coexpressed with recombinant factor VIII (rFVIII) in Chinese hamster ovary cells used to produce rFVIII for the treatment of hemophilia A. Here we describe the characterization of the structure and function of the rVWF drug product, with a focus on its in vitro platelet aggregation and matrix protein binding functions. Electron microscopy and multimer analysis revealed a highly organized structure for the rVWF protein, with a homogeneous multimer distribution including ultrahigh molecular weight multimers. The specific activity for binding to collagen and platelets mediated by ristocetin is higher in rVWF than in commercial plasma-derived VWF-FVIII complex products. The affinity and binding capacity of rVWF to FVIII is comparable to VWF in plasma. rVWF effectively binds to platelets and promotes platelet adhesion under shear stress similar to VWF in human plasma.
authors.affiliation: Baxter BioScience, Vienna, Austria. peter_turecek@baxter.com
authors.forename: Peter L
authors.initials: PL
authors.lastname: Turecek
authors.forename: Gerald
authors.initials: G
authors.lastname: Schrenk
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Rottensteiner
authors.forename: Katalin
authors.initials: K
authors.lastname: Varadi
authors.forename: Edouard
authors.initials: E
authors.lastname: Bevers
authors.forename: Peter
authors.initials: P
authors.lastname: Lenting
authors.forename: Nicola
authors.initials: N
authors.lastname: Ilk
authors.forename: Uwe B
authors.initials: UB
authors.lastname: Sleytr
authors.forename: Hartmut J
authors.initials: HJ
authors.lastname: Ehrlich
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Schwarz
mesh_terms: D000818:Animals; D006801:Humans; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D014842:von Willebrand Diseases / Q000188:drug therapy*; D014841:von Willebrand Factor / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D011994:Recombinant Proteins; D014841:von Willebrand Factor