Amyloid formation and mitochondrial dysfunction are characteristics of type 2 diabetes. The major peptide constituent of the amyloid deposits in type 2 diabetes is islet amyloid polypeptide (IAPP). In this study, we found that pitrilysin, a zinc metallopeptidase of the inverzincin family, degrades monomeric, but not oligomeric, islet amyloid polypeptide in vitro. In insulinoma cells when pitril...

There is accumulating evidence that interactions between beta-amyloid and copper, iron, and zinc are associated with the pathophysiology of Alzheimer's disease (AD). A significant dyshomeostasis of copper, iron, and zinc has been detected, and the mismanagement of these metals induces beta-amyloid precipitation and neurotoxicity. Chelating agents offer a potential therapeutic solution to the ne...

Amyloid fibrils are ordered polymers in which constituent polypeptides adopt a non-native fold. Despite their importance in degenerative human diseases, the overall structure of amyloid fibrils remains unknown. High-resolution studies of model peptide assemblies have identified residues forming cross-beta-strands and have revealed some details of local beta-strand packing. However, little is kn...

A conformational isoform of the mammalian prion protein (PrP(Sc)) is the sole component of the infectious pathogen that causes the prion diseases. We have obtained X-ray fiber diffraction patterns from infectious prions that show cross-beta diffraction: meridional intensity at 4.8 A resolution, indicating the presence of beta strands running approximately at right angles to the filament axis an...

Alzheimer’s disease (AD) is a progressive neurodegenerative, primarily concerned and leading cause of mortality worldwide which has no cure so far, the world. The progresses from memory loss to cognitive decline gradually. severity grows up mild, moderate severe. Hallmarks research AD reported, are identification amyloid-beta (Aβ) plaques tau protein tangles between within neuronal c...

objective: alzheimer’s disease is the most common type of neurodegenerative disorder. it has been suggested that oxidative stress can be one of the pathological mechanisms of this disease. carnosic acid (ca) is an effective antioxidant substance and recent studies have shown that its electrophilic compounds play a role in reversing oxidative stress. thus we tried to find out whether ca administ...

The islet in type 2 diabetes is characterized by a deficit in beta-cell mass, increased beta-cell apoptosis, and impaired insulin secretion. Also, islets in type 2 diabetes often contain deposits of islet amyloid derived from islet amyloid polypeptide (IAPP), a 37-amino acid protein cosecreted with insulin by beta-cells. Several lines of evidence suggest that proteins with a capacity to develop...