Summary
Rabbits immunized with crude whole fibrils from three amyloidotic spleens formed antibodies to the following plasma proteins: γ-A-immunoglobulin, γ-G-immunoglobulin, fibrinogen, a protein with β-globulin mobility and a protein with α-1-globulin mobility (P-component). Only P-component was present in each of the three different fibril preparations. When the amyloid fibrils were subjected to sucrose gradient centrifugation, it was possible to demonstrate that not only were the fibrils relatively free of contaminants, as determined by electron microscopy, but that γ-G-immunoglobulin which had been observed in the original crude preparation was no longer present. P-component was later identified in glycine extracts from sucrose-separated fibrils from four patients with primary amyloidosis, three patients with secondary amyloidosis and one patient with amyloidosis associated with multiple myeloma. Finally, the sedimentation coefficient of P-component was compared with that of albumin (4 S), γ-A- and γ-G-immunoglobulin (7 S) and γ-M-immunoglobulin (19 S) using a continuous sucrose gradient. It was found to be less than 19 S but greater than 7 S.
Footnotes
Grants in support of these investigations have been received from the United States Public Health Service, National Institute of Arthritis and Metabolic Diseases (Grants AM-05589, AM-04599 and T1 AM-5285) and from the Arthritis Foundation.
