{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T18:10:01Z","timestamp":1788891001223,"version":"build-2803163510"},"reference-count":75,"publisher":"National Academy of Sciences","issue":"37","license":[{"start":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T00:00:00Z","timestamp":1788825600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"German Research Foundation","doi-asserted-by":"crossref","award":["556478029"],"award-info":[{"award-number":["556478029"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100000062","name":"HHS | NIH | National Institute of Diabetes and Digestive and Kidney Diseases","doi-asserted-by":"publisher","award":["R01 DK046335"],"award-info":[{"award-number":["R01 DK046335"]}],"id":[{"id":"10.13039\/100000062","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[2026,9,15]]},"abstract":"<jats:p>Transthyretin (TTR) is a kinetically stable protein in the bloodstream, cerebrospinal fluid, and in the eye, whose aggregation causes a prominent human amyloid disease, TTR amyloidosis (ATTR). Dissociation of the wild-type TTR tetramer into metastable dimers is rate-limiting for aggregation at acidic pH and unfolding in denaturant solutions at neutral pH. However, this \u201ccanonical dimer\u201d pathway of denaturation is not the only one accessible under conditions possibly relevant to amyloid disease. At pH-values reached in the late endosome and lysosome (pH 4.0 to 5.0), as well as with perturbing mutations at neutral pH, a second denaturation pathway becomes accessible involving a more expanded transition state. This \u201calternative unfolding\u201d pathway is evident via a characteristic switch to a steeper slope in the plot of the log-transformed unfolding rate constant vs. the urea concentration. Using mutations, we identify globally distributed locations in the protein that are sensitive to pathway-switching and correlate them with structural information. We show that flux along the alternative denaturation pathway becomes kinetically competitive in a subset of variants under mildly acidic conditions. A small-molecule kinetic stabilizer of TTR decreases flux along the canonical denaturation pathway, and exhibits reduced influence on denaturation by the alternative pathway. We present a \u201cuniversal\u201d plot allowing classification of TTR mutants to either pathway, and suggest a mechanism by which the two pathways operate. We speculate that the existence of an alternative unfolding pathway could allow for rapid protein degradation and turnover of kinetically stable TTR under acidic conditions in the autolysosome.<\/jats:p>","DOI":"10.1073\/pnas.2536532123","type":"journal-article","created":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T17:47:37Z","timestamp":1788889657000},"update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":0,"title":["Transthyretin can denature by an alternative pathway"],"prefix":"10.1073","volume":"123","author":[{"given":"Marcus","family":"J\u00e4ger","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02dxx6824","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, The Scripps Research Institute","place":["La Jolla"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan-Hannes","family":"Sch\u00e4fer","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02dxx6824","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, The Scripps Research Institute","place":["La Jolla"]},{"id":[{"id":"https:\/\/ror.org\/02dxx6824","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Integrative Structural and Computational Biology, The Scripps Research Institute","place":["La Jolla"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4921-1135","authenticated-orcid":false,"given":"Gabriel C.","family":"Lander","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02dxx6824","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Integrative Structural and Computational Biology, The Scripps Research Institute","place":["La Jolla"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8185-8487","authenticated-orcid":false,"given":"Evan T.","family":"Powers","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02dxx6824","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, The Scripps Research Institute","place":["La Jolla"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9291-8123","authenticated-orcid":false,"given":"Martin","family":"Gruebele","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/047426m28","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, University of Illinois Urbana-Champaign","place":["Champaign"]},{"id":[{"id":"https:\/\/ror.org\/047426m28","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Physics, University of Illinois Urbana-Champaign","place":["Champaign"]},{"id":[{"id":"https:\/\/ror.org\/047426m28","id-type":"ROR","asserted-by":"publisher"}],"name":"Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign","place":["Champaign"]},{"id":[{"id":"https:\/\/ror.org\/047426m28","id-type":"ROR","asserted-by":"publisher"}],"name":"Carle-Illinois College of Medicine, University of Illinois Urbana-Champaign","place":["Champaign"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeffery W.","family":"Kelly","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02dxx6824","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Chemistry, The Scripps Research Institute","place":["La Jolla"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[2026,9,8]]},"reference":[{"key":"e_1_3_4_1_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.7754382"},{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41594-024-01472-7"},{"key":"e_1_3_4_3_2","doi-asserted-by":"publisher","DOI":"10.1107\/S0907444996003046"},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1097\/TP.0000000000000574"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.36.7.900"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00173a029"},{"key":"e_1_3_4_7_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1805689"},{"key":"e_1_3_4_8_2","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0b013e3182661eb1"},{"key":"e_1_3_4_9_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1716793"},{"key":"e_1_3_4_10_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1716153"},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/0140-6736(93)93127-M"},{"key":"e_1_3_4_12_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1062245"},{"key":"e_1_3_4_13_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1079589"},{"key":"e_1_3_4_14_2","first-page":"179","article-title":"A strikingly benign evolution of FAP in an individual found to be a compound heterozygote for two TTR mutations: TTR MET 30 and TTR MET 119","volume":"20","author":"Coelho T.","year":"1993","unstructured":"T. Coelho , A strikingly benign evolution of FAP in an individual found to be a compound heterozygote for two TTR mutations: TTR MET 30 and TTR MET 119. J. Rheumatol. 20, 179 (1993).","journal-title":"J. Rheumatol."},{"key":"e_1_3_4_15_2","doi-asserted-by":"publisher","DOI":"10.1126\/scitranslmed.aax0914"},{"key":"e_1_3_4_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi952501g"},{"key":"e_1_3_4_17_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi963195p"},{"key":"e_1_3_4_18_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00151a036"},{"key":"e_1_3_4_19_2","first-page":"228","article-title":"FAP mutations destabilize transthyretin facilitating conformational changes required for amyloid formation","volume":"199","author":"Colon W.","year":"1996","unstructured":"W. Colon , FAP mutations destabilize transthyretin facilitating conformational changes required for amyloid formation. Ciba Found. Symp. 199, 228\u2013238 (1996); discussion 239\u2013242.","journal-title":"Ciba Found. Symp."},{"key":"e_1_3_4_20_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi800636q"},{"key":"e_1_3_4_21_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi010673"},{"key":"e_1_3_4_22_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.202495199"},{"key":"e_1_3_4_23_2","doi-asserted-by":"publisher","DOI":"10.1002\/pro.70009"},{"key":"e_1_3_4_24_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi201362z"},{"key":"e_1_3_4_25_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2005.01.050"},{"key":"e_1_3_4_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi051608t"},{"key":"e_1_3_4_27_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi500171j"},{"key":"e_1_3_4_28_2","doi-asserted-by":"publisher","DOI":"10.1110\/ps.8901"},{"key":"e_1_3_4_29_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi050352o"},{"key":"e_1_3_4_30_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi011194d"},{"key":"e_1_3_4_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/0006-291X(88)90188-X"},{"key":"e_1_3_4_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jacc.2019.04.003"},{"key":"e_1_3_4_33_2","doi-asserted-by":"publisher","DOI":"10.1080\/13506129.2003.12088568"},{"key":"e_1_3_4_34_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.87.7.2843"},{"key":"e_1_3_4_35_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2315007121"},{"key":"e_1_3_4_36_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi030077a"},{"key":"e_1_3_4_37_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-2836(78)90368-6"},{"key":"e_1_3_4_38_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2011.12.060"},{"key":"e_1_3_4_39_2","doi-asserted-by":"publisher","DOI":"10.1021\/acs.jcim.2c00447"},{"key":"e_1_3_4_40_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.91.22.10426"},{"key":"e_1_3_4_41_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbc.2024.107495"},{"key":"e_1_3_4_42_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi500430w"},{"key":"e_1_3_4_43_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-2836(02)01230-5"},{"key":"e_1_3_4_44_2","doi-asserted-by":"publisher","DOI":"10.1021\/jacs.5b07370"},{"key":"e_1_3_4_45_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1201800109"},{"key":"e_1_3_4_46_2","doi-asserted-by":"publisher","DOI":"10.1038\/nsb947"},{"key":"e_1_3_4_47_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1515730113"},{"key":"e_1_3_4_48_2","doi-asserted-by":"publisher","DOI":"10.1107\/S090904951302075X"},{"key":"e_1_3_4_49_2","unstructured":"J. H. Schaefer G. C. Lander Human TTR-C10A at pH 4. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9ZDY. Deposited 26 November 2025."},{"key":"e_1_3_4_50_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmb.2008.07.029"},{"key":"e_1_3_4_51_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0006-3495(98)77529-0"},{"key":"e_1_3_4_52_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41431-019-0337-1"},{"key":"e_1_3_4_53_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.bpj.2020.08.043"},{"key":"e_1_3_4_54_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1097-2765(00)00117-9"},{"key":"e_1_3_4_55_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1802977115"},{"key":"e_1_3_4_56_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi991021c"},{"key":"e_1_3_4_57_2","doi-asserted-by":"publisher","DOI":"10.3109\/13506120308995253"},{"key":"e_1_3_4_58_2","doi-asserted-by":"publisher","DOI":"10.1080\/13506129.2019.1598358"},{"key":"e_1_3_4_59_2","doi-asserted-by":"publisher","DOI":"10.1021\/bi00135a022"},{"key":"e_1_3_4_60_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.95.22.12956"},{"key":"e_1_3_4_61_2","doi-asserted-by":"publisher","DOI":"10.1038\/ncomms7861"},{"key":"e_1_3_4_62_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja302528z"},{"key":"e_1_3_4_63_2","doi-asserted-by":"publisher","DOI":"10.1017\/S003358351400002X"},{"key":"e_1_3_4_64_2","doi-asserted-by":"publisher","DOI":"10.1042\/BJ20111690"},{"key":"e_1_3_4_65_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jbc.2021.101039"},{"key":"e_1_3_4_66_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0021-9258(18)68346-2"},{"key":"e_1_3_4_67_2","doi-asserted-by":"publisher","DOI":"10.1080\/13506120500352404"},{"key":"e_1_3_4_68_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-026-71794-1"},{"key":"e_1_3_4_69_2","doi-asserted-by":"publisher","DOI":"10.1002\/pro.3791"},{"key":"e_1_3_4_70_2","doi-asserted-by":"publisher","DOI":"10.1107\/S2059798318002425"},{"key":"e_1_3_4_71_2","doi-asserted-by":"publisher","DOI":"10.1002\/pro.3330"},{"key":"e_1_3_4_72_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41592-020-0731-1"},{"key":"e_1_3_4_73_2","doi-asserted-by":"crossref","unstructured":"M. Rafiq J. H. Schaefer G. C. Lander Human TTR-C10A at pH 7.4. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-74011. Deposited 21 November 2025.","DOI":"10.2210\/pdb9zbv\/pdb"},{"key":"e_1_3_4_74_2","doi-asserted-by":"crossref","unstructured":"M. Rafiq J. H. Schaefer G. C. Lander Human TTR-C10A at pH 7.4. Protein Data Bank. https:\/\/www.rcsb.org\/structure\/9ZBV. Deposited 21 November 2025.","DOI":"10.2210\/pdb9zbv\/pdb"},{"key":"e_1_3_4_75_2","unstructured":"J. H. Schaefer G. C. Lander Human TTR-C10A at pH 4. Electron Microscopy Data Bank. https:\/\/www.ebi.ac.uk\/emdb\/EMD-74078. Deposited 26 November 2025."}],"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.2536532123","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T17:48:07Z","timestamp":1788889687000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/10.1073\/pnas.2536532123"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,8]]},"references-count":75,"journal-issue":{"issue":"37","published-print":{"date-parts":[[2026,9,15]]}},"alternative-id":["10.1073\/pnas.2536532123"],"URL":"https:\/\/doi.org\/10.1073\/pnas.2536532123","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,8]]},"assertion":[{"value":"2025-12-18","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-27","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-08","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e2536532123"}}