{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,18]],"date-time":"2026-10-18T03:56:16Z","timestamp":1792295776137,"version":"4.4.0"},"reference-count":51,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,12,11]],"date-time":"2024-12-11T00:00:00Z","timestamp":1733875200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Strains of the syphilis spirochete, <jats:italic>Treponema pallidum<\/jats:italic> ssp. <jats:italic>pallidum<\/jats:italic>, group into one of two deep-branching clades: the Nichols clade or the globally dominant Street Strain 14 (SS14) clade. To date, in-depth proteome-wide analyses have focused on Nichols clade strains.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The <jats:italic>T. pallidum<\/jats:italic> SS14 clade reference strain (SS14) proteome was characterized via protein detection and quantification analyses using mass spectrometry, and comparison was made to the Nichols clade reference strain (Nichols) proteome.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Approximately two thirds of all proteins from <jats:italic>T. pallidum<\/jats:italic> SS14 were detected and quantitated, allowing confirmation of expression of 259 proteins for the first time in this strain, including 11 known\/putative outer membrane proteins (OMPs). SS14 and Nichols proteome comparative analyses demonstrated similar protein expression\/quantification profiles between the two strains, and showed that inter-strain amino acid sequence differences are located primarily within predicted surface-exposed regions in 16 known\/putative OMPs.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion<\/jats:title><jats:p>This study provides the first comparative analyses of the proteomes from the <jats:italic>T. pallidum<\/jats:italic> SS14 and Nichols strains. The findings inform syphilis vaccine design by confirming the expression of known\/predicted OMP vaccine candidates in SS14 treponemes, and via the finding that most inter-strain variable residues found in OMPs are predicted to be located in surface-exposed, host-facing regions of these proteins.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fmicb.2024.1505893","type":"journal-article","created":{"date-parts":[[2024,12,11]],"date-time":"2024-12-11T07:05:46Z","timestamp":1733900746000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Proteomic analysis of the Treponema pallidum subsp. pallidum SS14 strain: coverage and comparison with the Nichols strain proteome"],"prefix":"10.3389","volume":"15","author":[{"given":"Simon","family":"Houston","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven","family":"Marshall","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alloysius","family":"Gomez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline E.","family":"Cameron","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2024,12,11]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"493","DOI":"10.1038\/s41586-024-07487-w","article-title":"Accurate structure prediction of biomolecular interactions with AlphaFold 3","volume":"630","author":"Abramson","year":"2024","journal-title":"Nature"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"16245","DOI":"10.1038\/nmicrobiol.2016.245","article-title":"Origin of modern syphilis and emergence of a pandemic Treponema pallidum cluster","volume":"2","author":"Arora","year":"2016","journal-title":"Nat. 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