Codeposition of apolipoprotein A-IV and transthyretin in senile systemic (ATTR) amyloidosis.
Protein material was extracted from amyloid-rich sections of formalin-fixed and paraffin-embedded heart tissue from an individual with senile systemic amyloidosis, known to contain wild-type transthyretin as major amyloid fibril protein. Amino acid sequence analysis of tryptic peptides of this material revealed in addition to transthyretin sequences, also amino acid sequence corresponding to an N-terminal fragment of apolipoprotein A-IV. In immunohistochemistry, an antiserum to a synthetic apolipoprotein A-IV peptide labeled amyloid specifically. This peptide formed spontaneously amyloid-like fibrils in vitro and enhanced fibril formation from wild-type transthyretin. We conclude that several apolipoproteins, including apolipoprotein A-IV, may be important minor amyloid constituents, promoting fibril formation.
Bergström
J
J
Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden.
Murphy
C
C
Eulitz
M
M
Weiss
D T
DT
Westermark
G T
GT
Solomon
A
A
Westermark
P
P
D000367:Age Factors; D000595:Amino Acid Sequence; D000686:Amyloidosis / Q000473:pathology*; D001054:Apolipoproteins A / Q000302:isolation & purification*; D006801:Humans; D008969:Molecular Sequence Data; D009206:Myocardium / Q000737:chemistry* / Q000473:pathology; D011228:Prealbumin / Q000302:isolation & purification*
D001054:Apolipoproteins A; D011228:Prealbumin; C022205:apolipoprotein A-IV