Senile cardiac amyloid is related to prealbumin

The major component, protein ASC, isolated from the amyloid fibrils in senile cardiac amyloidosis, was characterized by structural studies of some peptic peptides. One of the peptides has an amino acid sequence identical to residues 70-90 in human prealbumin, and three other smaller peptides have a primary structure identical to that in positions 96-107, 109-115 and 121-127. The amino acid composition of the protein resembles that of human prealbumin but shows some characteristic differences. The protein has a blocked N-terminus and gives no visible precipitin reaction with antiserum to human prealbumin.