Amyloid refers to the abnormal fibrous, extracellular, proteinaceous deposits found in organs and tissues. Amyloid is insoluble and is structurally dominated by β-sheet structure. Unlike other fibrous proteins it does not commonly have a structural, supportive or motility role but is associated with the pathology seen in a range of diseases known as the amyloidoses. These diseases include Alzheimer's, the spongiform encephalopathies and type II diabetes, all of which are progressive disorders with associated high morbidity and mortality. Not surprisingly, research into the physicochemical properties and structure of amyloid and its formation is currently intensely pursued. Pancreatic islet amyloid deposits are a hallmark of type 2 diabetes (T2D). Islet amyloid, first reported almost 120 years ago as islet hyaline is found in > 90 % of individuals with T2D 2,3 . The main constituents of islet amyloid are fibrillar aggregates of the 37-residue polypeptide hormone islet amyloid peptide (IAPP), also called amylin. IAPP is detected in many organs including the
brain but is mainly localized in the beta cells of the pancreatic islets, where it is co-synthesized and co-secreted with insulin. Interestingly, the structure of these amyloids found in the pancreas resembles those also found in amyloid-beta fibrils observed in Alzheimer's patients brains. Here you can see the cryoEM structure of amyloid fibrils of islet amyloid polypeptide over an AI-generated neuron (PDB code: 6Y1A)

#molecularart ... #fibril .. #amyloid ... #pancreas ... #brain ... #alzheimer ... #cryoem

Structure rendered with @proteinimaging and depicted with @corelphotopaint