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dc.contributor.authorDevkota, Sujan
dc.contributor.authorWilliams, Todd D.
dc.contributor.authorWolfe, Michael S.
dc.date.accessioned2022-01-06T20:08:04Z
dc.date.available2022-01-06T20:08:04Z
dc.date.issued2021-01-12
dc.identifier.citationDevkota, S., Williams, T. D., & Wolfe, M. S. (2021). Familial Alzheimer's disease mutations in amyloid protein precursor alter proteolysis by γ-secretase to increase amyloid β-peptides of ≥45 residues. The Journal of biological chemistry, 296, 100281. https://doi.org/10.1016/j.jbc.2021.100281en_US
dc.identifier.urihttp://hdl.handle.net/1808/32359
dc.description.abstractProduction of amyloid β-protein (Aβ) is carried out by the membrane-embedded γ-secretase complex. Mutations in the transmembrane domain of amyloid β-protein precursor (APP) associated with early-onset familial Alzheimer's disease (FAD) can alter the ratio of aggregation-prone 42-residue Aβ (Aβ42) to 40-residue Aβ (Aβ40). However, APP substrate is proteolyzed processively by γ-secretase along two pathways: Aβ49→Aβ46→Aβ43→Aβ40 and Aβ48→Aβ45→Aβ42→Aβ38. Effects of FAD mutations on each proteolytic step are unknown, largely due to difficulties in detecting and quantifying longer Aβ peptides. To address this, we carried out systematic and quantitative analyses of all tri- and tetrapeptide coproducts from proteolysis of wild-type and 14 FAD-mutant APP substrates by purified γ-secretase. These small peptides, including FAD-mutant forms, were detected by tandem mass spectrometry and quantified by establishing concentration curves for each of 32 standards. APP intracellular domain (AICD) coproducts were quantified by immunoblot, and the ratio of AICD products corresponding to Aβ48 and Aβ49 was determined by mass spectrometry. Levels of individual Aβ peptides were determined by subtracting levels of peptide coproducts associated with degradation from those associated with production. This method was validated for Aβ40 and Aβ42 by specific ELISAs and production of equimolar levels of Aβ and AICD. Not all mutant substrates led to increased Aβ42/40. However, all 14 disease-causing mutations led to inefficient processing of longer forms of Aβ ≥ 45 residues. In addition, the effects of certain mutations provided insight into the mechanism of processive proteolysis: intermediate Aβ peptides apparently remain bound for subsequent trimming and are not released and reassociated.en_US
dc.publisherElsevieren_US
dc.rights© 2021 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC-BY license.en_US
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en_US
dc.subjectIntramembrane proteolysisen_US
dc.subjectMass spectrometryen_US
dc.subjectAmyloid β-protein (Aβ)en_US
dc.subjectAmyloid β-protein precursor (APP)en_US
dc.subjectPathogenesisen_US
dc.titleFamilial Alzheimer’s disease mutations in amyloid protein precursor alter proteolysis by γ-secretase to increase amyloid β-peptides of ≥45 residuesen_US
dc.typeArticleen_US
kusw.kuauthorDevkota, Sujan
kusw.kuauthorWilliams, Todd D.
kusw.kuauthorWolfe, Michael S.
kusw.kudepartmentMedicinal Chemistryen_US
kusw.kudepartmentMass Spectrometry Laboratoryen_US
dc.identifier.doi10.1016/j.jbc.2021.100281en_US
dc.identifier.orcidhttps://orcid.org/ 0000-0002-5721-9092en_US
kusw.oaversionScholarly/refereed, publisher versionen_US
kusw.oapolicyThis item meets KU Open Access policy criteria.en_US
dc.identifier.pmidPMC7948801en_US
dc.rights.accessrightsopenAccessen_US


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© 2021 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC-BY license.
Except where otherwise noted, this item's license is described as: © 2021 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC-BY license.