Specific chemical dissociation of fibrillar and non-fibrillar components of amyloid deposits.

In systemic amyloidosis, a fatal disorder for which there is no effective treatment, the extracellular protein deposits are composed of amyloid fibrils together with a non-fibrillar glycoprotein, amyloid P component (AP). Methyl 4,6-O-(1-carboxyethylidene)-beta-D-galactopyranoside (MO beta DG), a recently identified ligand for AP, was tested for its ability to produce in-vitro elution of AP which had been laid down with amyloid fibrils in vivo. Millimolar concentrations of MO beta DG completely dissociated AP from human and murine splenic amyloid deposits. Availability of this material thus provides for the first time the opportunity for specific molecular dissection of amyloid deposits. If MO beta DG or a related substance were effective in vivo it might be of therapeutic importance.