{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,6,21]],"date-time":"2026-06-21T11:47:39Z","timestamp":1782042459350,"version":"3.54.5"},"posted":{"date-parts":[[2026,3,15]]},"group-title":"Biophysics","reference-count":0,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,3,15]],"date-time":"2026-03-15T00:00:00Z","timestamp":1773532800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"name":"NIH","award":["F32GM161057"],"award-info":[{"award-number":["F32GM161057"]}]},{"name":"NIH","award":["R35GM158238"],"award-info":[{"award-number":["R35GM158238"]}]},{"name":"NIH","award":["1S10OD028655-01"],"award-info":[{"award-number":["1S10OD028655-01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,6,20]]},"abstract":"<jats:p>\n                  The nucleotide state and rates of transitions between states regulate the dynamics of ATPases. Slow inorganic phosphate (P\n                  <jats:sub>i<\/jats:sub>\n                  ) release following ATP hydrolysis is often rate-limiting and associated with key conformational changes. Actin filaments offer a unique opportunity to understand the fundamentals of phosphate release, because identical subunits at filament ends and the interior release P\n                  <jats:sub>i<\/jats:sub>\n                  at markedly different rates. The molecular origin of this difference is debated, so we employed extensive all-atom molecular dynamics simulations to characterize P\n                  <jats:sub>i<\/jats:sub>\n                  release from different subunits within an actin filament. The dissociation rates of P\n                  <jats:sub>i<\/jats:sub>\n                  from ADP-Mg\n                  <jats:sup>2+<\/jats:sup>\n                  in the active site correlate with biochemically measured P\n                  <jats:sub>i<\/jats:sub>\n                  release rates and scale inversely with the numbers of water molecules in the cavity surrounding the \u03b3-phosphate. Simulations show that egress of P\n                  <jats:sub>i<\/jats:sub>\n                  through protein channels, including through the N111-R177 backdoor, is not rate-limiting and, importantly, that subunits at the filament ends use alternative egress pathways.\n                <\/jats:p>","DOI":"10.64898\/2026.03.12.711388","type":"posted-content","created":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T04:20:11Z","timestamp":1773634811000},"source":"Crossref","is-referenced-by-count":0,"title":["Physical Confinement Modulates the Rate-Limiting Transition in the Release of Phosphate from Actin Filaments"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4923-5727","authenticated-orcid":false,"given":"Kristina M.","family":"Herman","sequence":"first","affiliation":[{"name":"University of Chicago;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-5591-5177","authenticated-orcid":false,"given":"Sahithya","family":"Sridharan Iyer","sequence":"additional","affiliation":[{"name":"University of Chicago;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yihang","family":"Wang","sequence":"additional","affiliation":[{"name":"University of Chicago;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1785-2969","authenticated-orcid":false,"given":"Thomas D.","family":"Pollard","sequence":"additional","affiliation":[{"name":"Yale University"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3267-6748","authenticated-orcid":false,"given":"Gregory A","family":"Voth","sequence":"additional","affiliation":[{"name":"University of Chicago;"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.03.12.711388","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,21]],"date-time":"2026-06-21T10:55:27Z","timestamp":1782039327000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.03.12.711388"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,15]]},"references-count":0,"URL":"https:\/\/doi.org\/10.64898\/2026.03.12.711388","relation":{},"subject":[],"published":{"date-parts":[[2026,3,15]]},"subtype":"preprint"}}