PARTIAL CHARACTERIZATION OF AMYLOID PROTEINS IN INHERITED AMYLOIDOSIS WITH LATTICE CORNEAL-DYSTROPHY AND IN SECONDARY AMYLOIDOSIS

Abstract

Amyloid fibrils isolated from 2 patients, 1 with inherited systemic amyloidosis and lattice corneal dystrophy, and the other with secondary amyloidosis due to chronic glomerulonephritis, were studied using immunologic, electrophoretic and chromatographic and chromatographic techniques. Amino acid hydrolysates of both amyloid types showed a high proportion of acidic and aliphatic amino acid residues but were non-identical in the overall amino acid composition. The preparations also contained 12-16% lipids. Guanidine hydrochloride denaturated amyloid fibrils of both types were resolved into 4 fractions in Sepharose 6B chromatography with MW of .apprx. 160,000, 45,000, 20,000 and 8000. The 160,000 MW fraction predominated in the chromatograms of inherited amyloid protein and was further resolved into 2 main fractions of 17,000 and 15,000 MW in sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. None of these fractions from inherited amyloid protein showed immunologic identity with tissue-derived amyloid protein A (AA) whereas all 4 fractions from secondary amyloid reacted against anti-AA antiserum. The 3 major Sepharose 6B fractions of secondary amyloid fibrils were resolved into a 25,000 MW fraction in SDS-polyacrylamide gel electrophoresis without urea but into a 12,000 MW fraction in gels containing 8M urea after more drastic dissolving conditions of the fibrils.