Binding of a protein chimera composed of a protein fragment containing a extracellular domain from __SP__ __NODE__ and of a protein fragment containing a extracellular domain from __SP__ __NODE__ protein and a protein chimera composed of a protein fragment containing a extracellular domain from mutant __NODE__ protein ( K84S ) and of a protein fragment containing a hinge domain and a CH2 domain ( from immunoglobulin ) and a CH3 domain ( from immunoglobulin ) from __SP__ __NODE__ occurs in a cell free system .