9iio | pdb_00009iio

J-shaped conformer of amyloid beta (1-40)

spinqualitylabelsall models 9iio, resolution 3.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 9iio is a 40 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.3Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease A4_HUMAN Defects in APP are the cause of Alzheimer disease type 1 (AD1) [MIM:104300. AD1 is a familial early-onset form of Alzheimer disease. It can be associated with cerebral amyloid angiopathy. Alzheimer disease is a neurodegenerative disorder characterized by progressive dementia, loss of cognitive abilities, and deposition of fibrillar amyloid proteins as intraneuronal neurofibrillary tangles, extracellular amyloid plaques and vascular amyloid deposits. The major constituent of these plaques is the neurotoxic amyloid-beta-APP 40-42 peptide (s), derived proteolytically from the transmembrane precursor protein APP by sequential secretase processing. The cytotoxic C-terminal fragments (CTFs) and the caspase-cleaved products such as C31 derived from APP, are also implicated in neuronal death. Defects in APP are the cause of cerebral amyloid angiopathy APP-related (CAA-APP) [MIM:605714. A hereditary localized amyloidosis due to amyloid-beta A4 peptide(s) deposition in the cerebral vessels. The principal clinical characteristics are recurrent cerebral and cerebellar hemorrhages, recurrent strokes, cerebral ischemia, cerebral infarction, and progressive mental deterioration. Patients develop cerebral hemorrhage because of the severe cerebral amyloid angiopathy. Parenchymal amyloid deposits are rare and largely in the form of pre-amyloid lesions or diffuse plaque-like structures. They are Congo red negative and lack the dense amyloid cores commonly present in Alzheimer disease. Some affected individuals manifest progressive aphasic dementia, leukoencephalopathy, and occipital calcifications. Function A4_HUMAN Functions as a cell surface receptor and performs physiological functions on the surface of neurons relevant to neurite growth, neuronal adhesion and axonogenesis. Involved in cell mobility and transcription regulation through protein-protein interactions. Can promote transcription activation through binding to APBB1-KAT5 and inhibits Notch signaling through interaction with Numb. Couples to apoptosis-inducing pathways such as those mediated by G(O) and JIP. Inhibits G(o) alpha ATPase activity (By similarity). Acts as a kinesin I membrane receptor, mediating the axonal transport of beta-secretase and presenilin 1. Involved in copper homeostasis/oxidative stress through copper ion reduction. In vitro, copper-metallated APP induces neuronal death directly or is potentiated through Cu(2+)-mediated low-density lipoprotein oxidation. Can regulate neurite outgrowth through binding to components of the extracellular matrix such as heparin and collagen I and IV. The splice isoforms that contain the BPTI domain possess protease inhibitor activity. Induces a AGER-dependent pathway that involves activation of p38 MAPK, resulting in internalization of amyloid-beta peptide and leading to mitochondrial dysfunction in cultured cortical neurons. Provides Cu(2+) ions for GPC1 which are required for release of nitric oxide (NO) and subsequent degradation of the heparan sulfate chains on GPC1. Beta-amyloid peptides are lipophilic metal chelators with metal-reducing activity. Bind transient metals such as copper, zinc and iron. In vitro, can reduce Cu(2+) and Fe(3+) to Cu(+) and Fe(2+), respectively. Beta-amyloid 42 is a more effective reductant than beta-amyloid 40. Beta-amyloid peptides bind to lipoproteins and apolipoproteins E and J in the CSF and to HDL particles in plasma, inhibiting metal-catalyzed oxidation of lipoproteins. Beta-APP42 may activate mononuclear phagocytes in the brain and elicit inflammatory responses. Promotes both tau aggregation and TPK II-mediated phosphorylation. Interaction with Also bind GPC1 in lipid rafts. Appicans elicit adhesion of neural cells to the extracellular matrix and may regulate neurite outgrowth in the brain (By similarity). The gamma-CTF peptides as well as the caspase-cleaved peptides, including C31, are potent enhancers of neuronal apoptosis. N-APP binds TNFRSF21 triggering caspase activation and degeneration of both neuronal cell bodies (via caspase-3) and axons (via caspase-6). Publication Abstract from PubMed Although the structural diversity of amyloid-beta (Abeta) fibrils plays a critical role in the pathology of Alzheimer's disease (AD), the mechanisms underlying this diversity remain poorly understood. In this study, we report the discovery of a novel J-shaped protomer structure of Abeta40 fibrils, resolved at 3.3 A resolution using cryo-electron microscopy. Under controlled conditions (20 mM sodium phosphate buffer, pH 8.0) designed to emphasize intra-protomer interactions and slow fibril elongation, the J-shaped structure revealed distinct salt bridges (e.g., D1-K28, R5-E22) that stabilize the fibril core. These findings expand our understanding of the free energy landscape of fibril formation, shedding light on how specific environmental factors, such as pH and ionic strength, may influence fibril polymorphism. Importantly, the unique features of the J-shaped protomer provide insights into the structural basis of amyloid plaque diversity in AD and suggest potential therapeutic strategies targeting intra-protomer interactions. This study underscores the importance of fibril polymorphism in AD pathology and offers a foundation for future research into fibril-targeted therapies. Elucidating the Unique J-Shaped Protomer Structure of Amyloid-beta(1-40) Fibril with Cryo-Electron Microscopy.,Burton-Smith RN, Yagi-Utsumi M, Yanaka S, Song C, Murata K, Kato K Int J Mol Sci. 2025 Jan 29;26(3):1179. doi: 10.3390/ijms26031179. PMID:39940945 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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