Amino acid position-specific contributions to amyloid beta-protein oligomerization
| Popis souboru: | application/pdf |
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| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::14480fcfa3ca84386f21dc9c14cbe432 https://escholarship.org/uc/item/1c54k7cv |
| Rights: | OPEN |
| Přírůstkové číslo: | edsair.dedup.wf.001..14480fcfa3ca84386f21dc9c14cbe432 |
| Autor: | Maji, Samir K, Ogorzalek Loo, Rachel R, Inayathullah, Mohammed, Spring, Sean M, Vollers, Sabrina S, Condron, Margaret M, Bitan, Gal, Loo, Joseph A, Teplow, David B |
| Rok vydání: | 2009 |
| Předmět: |
Aging
Biochemistry & Molecular Biology Amyloid beta-Peptides Protein Conformation Molecular Sequence Data Neurosciences Alzheimer's Disease including Alzheimer's Disease Related Dementias (AD/ADRD) Neurodegenerative Biological Sciences Alzheimer's Disease Medical and Health Sciences Peptide Fragments Brain Disorders nervous system diseases 5.1 Pharmaceuticals mental disorders Chemical Sciences Acquired Cognitive Impairment Humans Dementia Amino Acid Sequence Development of treatments and therapeutic interventions Protein Multimerization Sequence Alignment |
| Zdroj: | The Journal of biological chemistry, vol 284, iss 35 |
| Popis: | Understanding the structural and assembly dynamics of the amyloid beta-protein (Abeta) has direct relevance to the development of therapeutic agents for Alzheimer disease. To elucidate these dynamics, we combined scanning amino acid substitution with a method for quantitative determination of the Abeta oligomer frequency distribution, photo-induced cross-linking of unmodified proteins (PICUP), to perform "scanning PICUP." Tyr, a reactive group in PICUP, was substituted at position 1, 10, 20, 30, or 40 (for Abeta40) or 42 (for Abeta42). The effects of these substitutions were probed using circular dichroism spectroscopy, thioflavin T binding, electron microscopy, PICUP, and mass spectrometry. All peptides displayed a random coil --> alpha/beta --> beta transition, but substitution-dependent alterations in assembly kinetics and conformer complexity were observed. Tyr(1)-substituted homologues of Abeta40 and Abeta42 assembled the slowest and yielded unusual patterns of oligomer bands in gel electrophoresis experiments, suggesting oligomer compaction had occurred. Consistent with this suggestion was the observation of relatively narrow [Tyr(1)]Abeta40 fibrils. Substitution of Abeta40 at the C terminus decreased the population conformational complexity and substantially extended the highest order of oligomers observed. This latter effect was observed in both Abeta40 and Abeta42 as the Tyr substitution position number increased. The ability of a single substitution (Tyr(1)) to alter Abeta assembly kinetics and the oligomer frequency distribution suggests that the N terminus is not a benign peptide segment, but rather that Abeta conformational dynamics and assembly are affected significantly by the competition between the N and C termini to form a stable complex with the central hydrophobic cluster. |
| Databáze: | OpenAIRE |
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