Spontaneous diabetes mellitus in transgenic mice expressing human islet amyloid polypeptide.
Although the b-helix is a plausible structural motif for amyloid fibrils, it has not yet been proven that bona fide b-helices occur in amyloid fibrils.
Detailed structural information has been difficult to obtain by conventional techniques because of the inherent non-crystalline and insoluble nature of amyloid fibrils.
These models were antiparallel b-helices, presumably because the more common occurrence of parallel b-sheets in amyloid fibrils had not yet been established.
Xray analysis suggests that a protofilament in this amyloid is composed of a single pair of -sheets in the normal cross- conformation.
This latter reflection, of course, can only occur if the amyloid fibrils, or protofilaments, are composed of two or more -sheets.
Synthetic peptides homologous to prion protein residues 106-147 form amyloid-like fibrils in vitro.
The oligomerization of amyloid beta-protein begins intracellularly in cells derived from human brain.
