{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T14:51:08Z","timestamp":1786632668409,"version":"build-2736575974"},"reference-count":44,"publisher":"American Chemical Society (ACS)","issue":"32","license":[{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/100023043","name":"State of Florida","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100023043","id-type":"DOI","asserted-by":"publisher"}]},{"name":"NSF Cooperative Agreement","award":["DMR-2128556"],"award-info":[{"award-number":["DMR-2128556"]}]},{"name":"FSU"},{"name":"NIH","award":["R35GM13973"],"award-info":[{"award-number":["R35GM13973"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,13]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Correlating 15N resonances is attractive for establishing sequential connectivity between neighboring residues in structural studies of biomolecules. However, 15N\u201315N correlation experiments remain challenging because of extremely weak dipolar couplings between 15N spins. Here, we revisit the proton-assisted recoupling (PAR) scheme that facilitates magnetization exchange among dilute spins such as 13C or 15N. By selecting carbonyl carbons and monitoring magnetization transfers to other carbons under different RF field strengths under magic angle spinning (MAS), we find that the regular cross-polarization matching condition, i.e., \u03bdH \u2013 \u03bdC = \u00b1\u03bdr, where \u03bdH and \u03bdC are the spin-lock RF field strengths for 1H and 13C, respectively, and \u03bdr is the MAS frequency, leads to rapid spin-exchange processes. Furthermore, we demonstrate that this optimized condition can be directly used to obtain efficient 15N\u201315N correlations with mixing times of only a few milliseconds in uniformly 15N-labeled aquaporin reconstituted in POPC\/POPG lipid vesicles.<\/jats:p>","DOI":"10.1021\/acs.jpclett.6c01881","type":"journal-article","created":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T13:15:43Z","timestamp":1785849343000},"page":"9425-9431","source":"Crossref","is-referenced-by-count":0,"title":["Two-Dimensional\nHomonuclear Chemical Shift Correlation\nthrough Cross-Polarization Matching Condition in the PAR Scheme under\nMagic-Angle-Spinning of Solids"],"prefix":"10.1021","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0075-0410","authenticated-orcid":true,"given":"Riqiang","family":"Fu","sequence":"first","affiliation":[{"name":"United Imaging NMRSpec Scientific Instrument Co. Ltd , , ,","place":["Wuhan, Hubei, China, 430206"]},{"name":"Florida State University , , 1800 East Paul Dirac Drive , , ,","place":["Tallahassee, Florida, United States, 32310"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1964-1900","authenticated-orcid":true,"given":"Ayyalusamy","family":"Ramamoorthy","sequence":"additional","affiliation":[{"name":"Florida State University , , 1800 East Paul Dirac Drive , , ,","place":["Tallahassee, Florida, United States, 32310"]},{"name":"Florida State University , , 2525 Pottsdamer Street , , ,","place":["Tallahassee, Florida, United States, 32310"]},{"name":"Florida State University , , 91 Chieftan Way , , ,","place":["Tallahassee, Florida, United States, 32306"]},{"name":"University of Michigan , , , ,","place":["Ann Arbor, Michigan, United States, 48109"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,7,29]]},"reference":[{"key":"2026081310065238400_cit1","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1023\/A:1008280716360","article-title":"Experiments\nand Strategies for the\nAssignment of Fully 13C\/15N-Labelled Polypeptides\nby Solid State NMR","volume":"12","author":"Straus","year":"1998","journal-title":"J. Biomol. NMR"},{"key":"2026081310065238400_cit2","doi-asserted-by":"publisher","first-page":"2","DOI":"10.1038\/s43586-020-00002-1","article-title":"Solid-state NMR spectroscopy","volume":"1","author":"Reif","year":"2021","journal-title":"Nat. Rev. Methods\nPrimers"},{"key":"2026081310065238400_cit3","doi-asserted-by":"publisher","first-page":"272","DOI":"10.1002\/1439-7633(20010401)2:4&lt;272::AID-CBIC272&gt;3.3.CO;2-U","article-title":"Backbone and\nside-chain C-13 and N-15 signal assignments of the alpha-spectrin\nSH3 domain by magic angle spinning solid-state NMR at 17.6 T","volume":"2","author":"Pauli","year":"2001","journal-title":"Chem. Biochem."},{"key":"2026081310065238400_cit4","doi-asserted-by":"publisher","first-page":"8618","DOI":"10.1021\/ja0503128","article-title":"Protein\nStructure Determination by\nHigh-Resolution Solid-State NMR Spectroscopy: Application to Microcrystalline\nUbiquitin","volume":"127","author":"Zech","year":"2005","journal-title":"J. Am. Chem. Soc."},{"key":"2026081310065238400_cit5","doi-asserted-by":"publisher","first-page":"12291","DOI":"10.1021\/ja044497e","article-title":"Magic-Angle Spinning\nSolid-State NMR Spectroscopy of the \u03b21 Immunoglobulin Binding\nDomain of Protein G (GB1): 15N and 13C Chemical\nShift Assignments and Conformational Analysis","volume":"127","author":"Franks","year":"2005","journal-title":"J. Am. Chem. Soc."},{"key":"2026081310065238400_cit6","doi-asserted-by":"publisher","first-page":"265","DOI":"10.1007\/s10858-013-9745-7","article-title":"Identifying inter-residue resonances\nin crowded 2D 13C-13C chemical shift correlation\nspectra of membrane proteins by solid-state MAS NMR difference spectroscopy","volume":"56","author":"Miao","year":"2013","journal-title":"J. Biomol. 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Magn. Reson."},{"key":"2026081310065238400_cit25","doi-asserted-by":"publisher","first-page":"728","DOI":"10.1021\/ja0650394","article-title":"Proton\nAssisted Insensitive Nuclei\nCross Polarization","volume":"129","author":"Lewandowski","year":"2007","journal-title":"J. Am. Chem. Soc."},{"key":"2026081310065238400_cit26","doi-asserted-by":"publisher","first-page":"245101","DOI":"10.1063\/1.3036928","article-title":"Proton assisted recoupling and proton structure determination","volume":"129","author":"de Paepe","year":"2008","journal-title":"J. Chem. Phys."},{"key":"2026081310065238400_cit27","doi-asserted-by":"publisher","first-page":"9062","DOI":"10.1021\/jp810280t","article-title":"Proton\nAssisted Recoupling at High Spinning Frequencies","volume":"113","author":"Lewandowski","year":"2009","journal-title":"J. Phys. Chem. 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Reson."},{"key":"2026081310065238400_cit34","doi-asserted-by":"publisher","first-page":"15801","DOI":"10.1021\/jacs.6b08376","article-title":"Probing Hydronium\nIon Histidine NH Exchange Rate Constants in the M2 Channel via Indirect\nObservation of Dipolar-Dephased 15N Signals in Solid-State\nMagic-Angle-Spinning NMR","volume":"138","author":"Fu","year":"2016","journal-title":"J. Am. Chem. Soc."},{"key":"2026081310065238400_cit35","doi-asserted-by":"publisher","first-page":"5921","DOI":"10.1021\/ja00307a016","article-title":"Crystal\nenvironments and geometries of leucine, isolucine, valine, and phenylalanine\nprovide estimates of minimum nonbonded contact and preferred van der\nWaals interaction distances","volume":"107","author":"Gould","year":"1985","journal-title":"J. Am. Chem. Soc."},{"key":"2026081310065238400_cit36","volume-title":"High Resolution NMR in\nSolids, Selective Averaging","author":"Haeberlen","year":"1976"},{"key":"2026081310065238400_cit37","doi-asserted-by":"publisher","first-page":"105","DOI":"10.1016\/j.jmr.2014.06.005","article-title":"Differentiation of\nhistidine tautomeric\nstates using 15N selectively filtered 13C solid-state\nNMR spectroscopy","volume":"245","author":"Miao","year":"2014","journal-title":"J. Magn. Reson."},{"key":"2026081310065238400_cit38","doi-asserted-by":"publisher","first-page":"106757","DOI":"10.1016\/j.jmr.2020.106757","article-title":"Revealing\nWeak Histidine 15N Homonuclear Scalar Couplings using Solid-State\nMagic-Angle-Spinning\nNMR Spectroscopy","volume":"316","author":"Tan","year":"2020","journal-title":"J. Magn. Reson."},{"key":"2026081310065238400_cit39","doi-asserted-by":"publisher","first-page":"2325","DOI":"10.1063\/1.1534105","article-title":"13C-1H dipolar-driven\n13C-13C recoupling\nwithout 13C rf irradiation in nuclear magnetic resonance of rotating\nsolids","volume":"118","author":"Takegoshi","year":"2003","journal-title":"J. Chem. Phys."},{"key":"2026081310065238400_cit40","doi-asserted-by":"publisher","first-page":"7885","DOI":"10.1021\/jacs.8b03446","article-title":"Gating Mechanism of\nAquaporin Z in Synthetic Bilayers and Native\nMembranes Revealed by Solid-State NMR Spectroscopy","volume":"140","author":"Zhao","year":"2018","journal-title":"J. Am. Chem. Soc."},{"key":"2026081310065238400_cit41","doi-asserted-by":"publisher","first-page":"286","DOI":"10.1006\/jmre.2002.2588","article-title":"2D 13C-13C MAS NMR correlation\nspectroscopy with mixing by true 1H spin diffusion reveals\nlong-range intermolecular distance restraints in ultra-high magnetic\nfield","volume":"157","author":"de Boer","year":"2002","journal-title":"J. Magn. Reson."},{"key":"2026081310065238400_cit42","doi-asserted-by":"publisher","first-page":"173","DOI":"10.1016\/j.jmr.2009.04.013","article-title":"CHHC and 1H-1H magnetization exchange: analysis\nby experimental\nsolid-state NMR and 11-spin density-matrix simulations","volume":"199","author":"Aluas","year":"2009","journal-title":"J. Magn. Reson."},{"key":"2026081310065238400_cit43","doi-asserted-by":"publisher","first-page":"24687","DOI":"10.1021\/acs.jpcc.7b08841","article-title":"Measuring long-range 13C-13C correlations on a surface under natural\nabundance\nusing dynamic nuclear polarization-enhanced solid-state nuclear magnetic\nresonance","volume":"121","author":"Kobayashi","year":"2017","journal-title":"J. Phys. Chem. C"},{"key":"2026081310065238400_cit44","doi-asserted-by":"publisher","first-page":"12640","DOI":"10.1021\/ja034555g","article-title":"Analysis of\nproton-proton transfer dynamics in rotating solids and their use for\n3D structure determination","volume":"125","author":"Lange","year":"2003","journal-title":"J. Am. Chem. Soc."}],"container-title":["The Journal of Physical\nChemistry Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acs.jpclett.6c01881","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/jpclcd\/article-pdf\/17\/32\/9425\/66324166\/acs.jpclett.6c01881.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/jpclcd\/article-pdf\/17\/32\/9425\/66324166\/acs.jpclett.6c01881.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T14:11:52Z","timestamp":1786630312000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/jpclcd\/article\/17\/32\/9425\/5236355\/Two-Dimensional-Homonuclear-Chemical-Shift"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,29]]},"references-count":44,"journal-issue":{"issue":"32","published-online":{"date-parts":[[2026,7,29]]},"published-print":{"date-parts":[[2026,8,13]]}},"URL":"https:\/\/doi.org\/10.1021\/acs.jpclett.6c01881","relation":{},"ISSN":["1948-7185"],"issn-type":[{"value":"1948-7185","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,29]]}}}