Beta 2-microglobulin, different fragments and polymers thereof in synovial amyloid in long-term hemodialysis.
Amyloid deposits of a patient with long-term hemodialysis were immunohistochemically identified as beta 2-microglobulin (beta 2m)-derived. Amyloid proteins were isolated from fibril concentrates from the synovia by HPLC permeation chromatography. Further analysis included dot immunoassay, immunodiffusion, SDS-polyacrylamide gel electrophoresis and Western blotting. Proteins with molecular masses of 8.5, 12, 17 and 24 kDa as well as polymers of higher molecular mass were detected. Neither the 24-kDa dimer nor the higher polymers could be significantly reduced by disulfide reagents. The N-terminal amino-acid sequence analyses of the two major proteins of 12 and 24 kDa showed the same two sequences each: one commencing with position 1 and the other with position 7 of beta 2m. These results suggest that limited proteolysis and polymer formation independent from interchain disulfide bridging, both play a role in the genesis of beta 2m-derived amyloid in the synovia.
D000595:Amino Acid Sequence; D000682:Amyloid / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006651:Histocytochemistry; D006801:Humans; D007120:Immunochemistry; D007676:Kidney Failure, Chronic / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D006435:Renal Dialysis; D000685:Serum Amyloid A Protein / Q000032:analysis; D013582:Synovial Fluid / Q000032:analysis*; D001613:beta 2-Microglobulin / Q000032:analysis*
D000682:Amyloid; D000685:Serum Amyloid A Protein; D001613:beta 2-Microglobulin