Expressed full-length von Willebrand factor containing missense mutations linked to type IIB von Willebrand disease shows enhanced binding to platelets. Blood 1992 Apr 15;79(8):2048-55
Date
04/15/1992Pubmed ID
1373334Scopus ID
2-s2.0-0026700987 (requires institutional sign-in at Scopus site) 54 CitationsAbstract
von Willebrand disease (vWD) variant type IIB is an inherited bleeding disorder resulting from the spontaneous binding of defective von Willebrand factor (vWF) to platelets in vivo. To identify the molecular basis for type IIB vWD, we used reverse transcription and the polymerase chain reaction to examine the nucleotide sequence of the platelet glycoprotein (GP) Ib-binding domain encoded by the vWF messenger RNA in an affected family, and in an unrelated affected individual. We identified two different missense mutations linked with expression of type IIB vWD. These mutations, which lead to Pro574----Leu and Val553----Met substitutions, respectively, were each introduced into the full-length vWF expression vector pvW198, and both wild-type (wt) and mutant vWF were transiently expressed in COS-7 cells. Binding assays showed that both mutant proteins showed significant non-ristocetin-dependent spontaneous binding to platelets, and that complete binding was induced by low concentrations of ristocetin that failed to induce platelet binding by wt vWF. The vWF/platelet interaction was inhibited by the anti-vWF monoclonal antibody (MoAb) AvW3, and the anti-GPIb MoAb AP1, which both block vWF binding to platelets. These results show that the identified missense mutations are the likely basis for the expression of type IIB vWD in these affected individuals.
Author List
Kroner PA, Kluessendorf ML, Scott JP, Montgomery RRAuthor
Robert R. Montgomery MD Adjunct Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBase Sequence
Blood Platelets
Cloning, Molecular
DNA
Endothelium, Vascular
Female
Humans
Leukocytes
Male
Molecular Sequence Data
Mutation
Oligonucleotides, Antisense
Pedigree
Platelet Membrane Glycoproteins
Polymerase Chain Reaction
Protein Binding
RNA
Receptors, Cell Surface
Recombinant Proteins
Ristocetin
Transfection
von Willebrand Diseases
von Willebrand Factor
