von Willebrand因子(vWF)のヒトType Ⅲ collagenへの結合に関する研究 ： Ⅰ. ヒトType Ⅲ collagenを用いた正常血漿中のvWFのcollagen結合

Abstract

A new assay system of the binding of vWF to collagen was established using human Type Ⅲ fibrillar collagen suspension. The principle of this method is as follows : a small amount of sample plasma was added to a suspension containing human Type Ⅲ collagen ; after centrifugation, vWF : Ag level in the supernatant was measured by ELISA ; then collagen binding was estimated according to the formula : collagen binding (%)=(A-B)/A×100 where, A=WF : Ag after binding with denatured collagen (heat-treated at 80℃ for 1 hr) and B=vWF : Ag after binding with fibrillar collagen. When a purified vWF sample was used in this assay, all vWF : Ag was bound to the collagen fiber. On the other hand, addition of an anti-vWF monoclonal antibody (NMC-vW/3), which recognizes collagen binding domain of vWF subunit, inhibited binding of vWF to collagen compeletely, but EDTA or heparin did not. The collagen binding in 50 normal adult plasmas was 84.0%～98.1% (93.4±2.6%) and vWF : Ag × collagen binding/100 correlated well to Rcof activity. The assay system is very simple technically and could be useful to measure the binding of vWF to collagen.