TY - JOUR
T1 - The pro-polypeptide of von Willebrand factor is required for the formation of a functional factor VIII-binding site on mature von Willebrand factor
AU - Leyte, A.
AU - Voorberg, J.
AU - van Schijndel, H. B.
AU - Duim, B.
AU - Pannekoek, H.
AU - van Mourik, J. A.
PY - 1991
Y1 - 1991
N2 - We have established that a recombinant von Willebrand Factor (vWF) mutant (vWFdelpro) that lacks the propolypeptide, in contrast with mature wild-type vWF, with which it is identical in terms of primary amino acid sequence, is not able to form a complex with Factor VIII. Wild-type vWF (flvWF) and vWFdelpro were expressed in AtT-20 cells. Under the culture conditions employed, completely processed multimerized flvWF and dimeric vWFdelpro were secreted into the medium. FlvWF and vWFdelpro were compared for their Factor VIII-binding properties in two distinct assay systems. In a direct binding assay, purified human Factor VIII was shown to bind to flvWF that had been immobilized on the surface of microtitre wells by using an anti-vWF monoclonal antibody. In contrast, Factor VIII did not bind to immobilized vWFdelpro. In a competition assay, fluid-phase flvWF appeared to inhibit efficiently the binding of Factor VIII to immobilized vWF isolated from plasma, whereas vWFdelpro did not influence Factor VIII binding. From these observations, it is argued that the pro-polypeptide serves an essential role in the post-translational processes that lead to the expression of a functional Factor VIII-binding site on the mature vWF subunit
AB - We have established that a recombinant von Willebrand Factor (vWF) mutant (vWFdelpro) that lacks the propolypeptide, in contrast with mature wild-type vWF, with which it is identical in terms of primary amino acid sequence, is not able to form a complex with Factor VIII. Wild-type vWF (flvWF) and vWFdelpro were expressed in AtT-20 cells. Under the culture conditions employed, completely processed multimerized flvWF and dimeric vWFdelpro were secreted into the medium. FlvWF and vWFdelpro were compared for their Factor VIII-binding properties in two distinct assay systems. In a direct binding assay, purified human Factor VIII was shown to bind to flvWF that had been immobilized on the surface of microtitre wells by using an anti-vWF monoclonal antibody. In contrast, Factor VIII did not bind to immobilized vWFdelpro. In a competition assay, fluid-phase flvWF appeared to inhibit efficiently the binding of Factor VIII to immobilized vWF isolated from plasma, whereas vWFdelpro did not influence Factor VIII binding. From these observations, it is argued that the pro-polypeptide serves an essential role in the post-translational processes that lead to the expression of a functional Factor VIII-binding site on the mature vWF subunit
U2 - https://doi.org/10.1042/bj2740257
DO - https://doi.org/10.1042/bj2740257
M3 - Article
C2 - 1900418
SN - 0264-6021
VL - 274 ( Pt 1)
SP - 257
EP - 261
JO - Biochemical journal
JF - Biochemical journal
ER -