PURIFICATION AND PARTIAL CHARACTERIZATION OF A NEW 85KDA AMYLOIDOSIS-RELATED PROTEIN IN CHRONIC-HEMODIALYSIS

An 85 KDa protein was purified by a multistep procedure (ultracentrifugation, HPLC, SDS-PAGE) from sera and amyloid deposits of patients on chronic hemodialysis and was characterized as a novel protein on the basis of its NH2 terminus (KVQLVE-V). This protein was formed by two subunits with Mr of 55 and 30 KDa and had affinity for Thyoflavin T, a fluorescent dye which was employed for labelling the protein prior HPLC. The 85 KDa was the only fluorescent component of ultracentrifugates from the serum of hemodialyzed patients while in amyloid fibrils it coexisted in roughly equimolar amounts with β2-microglobulin. This new high molecular weight protein which accumulates in uremia, could be co-responsible with β2-microglobulin for hemodialysis-related osteoarticular amyloidosis. © 1991.