barrow-alzheimersdisease-2001.pdf (213.04 kB)
Alzheimer's disease amyloid-β binds copper and zinc to generate an allosterically ordered membrane-penetrating structure containing superoxide dismutase-like subunits
journal contribution
posted on 2001-06-08, 00:00 authored by C C Curtain, F Ali, I Volitakis, R A Cherny, R S Norton, K Beyreuther, Colin BarrowColin Barrow, C L Masters, A I Bush, K J BarnhamAmyloid beta peptide (Abeta) is the major constituent of extracellular plaques and perivascular amyloid deposits, the pathognomonic neuropathological lesions of Alzheimer's disease. Cu(2+) and Zn(2+) bind Abeta, inducing aggregation and giving rise to reactive oxygen species. These reactions may play a deleterious role in the disease state, because high concentrations of iron, copper, and zinc have been located in amyloid in diseased brains. Here we show that coordination of metal ions to Abeta is the same in both aqueous solution and lipid environments, with His(6), His(13), and His(14) all involved. At Cu(2+)/peptide molar ratios >0.3, Abeta coordinated a second Cu(2+) atom in a highly cooperative manner. This effect was abolished if the histidine residues were methylated at N(epsilon)2, indicating the presence of bridging histidine residues, as found in the active site of superoxide dismutase. Addition of Cu(2+) or Zn(2+) to Abeta in a negatively charged lipid environment caused a conformational change from beta-sheet to alpha-helix, accompanied by peptide oligomerization and membrane penetration. These results suggest that metal binding to Abeta generated an allosterically ordered membrane-penetrating oligomer linked by superoxide dismutase-like bridging histidine residues.
History
Journal
Journal of biological chemistryVolume
276Issue
23Pagination
20466 - 20473Publisher
American Society for Biochemistry and Molecular BiologyLocation
Bethesda, Md.Publisher DOI
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ISSN
0021-9258Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2001, American Society for Biochemistry and Molecular BiologyUsage metrics
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