{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T21:10:36Z","timestamp":1790111436508,"version":"4.0.1"},"posted":{"date-parts":[[2026,9,18]]},"group-title":"Biophysics","reference-count":56,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T00:00:00Z","timestamp":1789689600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.biorxiv.org\/about\/FAQ#license"}],"funder":[{"name":"National Institutes of Health","award":["R01GM125995"],"award-info":[{"award-number":["R01GM125995"]}]},{"name":"National Institutes of Health","award":["R35GM161252"],"award-info":[{"award-number":["R35GM161252"]}]},{"name":"National Institutes of Health","award":["S10 OD012245."],"award-info":[{"award-number":["S10 OD012245."]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,9,18]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Nuclear magnetic resonance (NMR) spectroscopy provides atomic-resolution insights into biomolecular structure, dynamics and interactions under non-perturbative conditions. However, the widespread applicability of this technique continues to be limited by its intrinsically low sensitivity. This drawback is particularly severe in the case of concentration-limited samples. Low-concentration photochemically induced dynamic nuclear polarization (LC-photo-CIDNP) is an optically enhanced NMR hyperpolarization strategy capable of boosting NMR sensitivity\n                  <jats:italic>in situ<\/jats:italic>\n                  by several orders of magnitude under physiologically relevant environments. Yet, the inherent nature of the LC-photo-CIDNP phenomenon confines the achievable enhancements to only a subset of nuclei, thus limiting the extent of attainable residue-specific information. Here, we overcome this shortcoming by integrating LC-photo-CIDNP with Total Correlation Spectroscopy (TOCSY) to propagate initial hyperpolarization to other nuclei via scalar-coupled spin networks. First, we demonstrate efficient through-bond transfer of LC-photo-CIDNP enhanced signals throughout entire intramolecular atomic frameworks via 1D \u00b9H- and \u00b9\u00b3C-detected experiments. Second, we extend the approach to a model protein and demonstrate efficient polarization transfer via 1D and 2D \u00b9H-detected \u00b9\u00b3C-TOCSY LC-photo-CIDNP. Intrinsically photo-CIDNP-inactive nuclei can thus be visualized via\n                  <jats:sup>13<\/jats:sup>\n                  C-\n                  <jats:sup>1<\/jats:sup>\n                  H correlations within minutes down to 10 \u03bcM concentration. In all, this work establishes a general strategy to achieve through-bond propagation of LC-photo-CIDNP hyperpolarization. This technology enables gaining residue-specific structural insights on amino acids and proteins at previously unattainable low concentrations.\n                <\/jats:p>\n                <jats:sec>\n                  <jats:title>Significance Statement<\/jats:title>\n                  <jats:p>Nuclear magnetic resonance (NMR) plays a key role in the elucidation of biomolecular structure, dynamics and interactions. Yet, it is extremely insensitive. Here, we synergistically combine an optically enhanced NMR technology known as LC-photo-CIDNP with total correlation spectroscopy (TOCSY). Via this approach, we achieve highly enhanced detection thresholds, together with dramatic increases in the number of hyperpolarized nuclei. This technology is readily applicable to both amino acids and proteins in solution. Remarkably, TOCSY-enhanced LC-photo-CIDNP enables a tunable degree of through-bond hyperpolarization propagation, with no restrictions in biomolecular tumbling or compaction. In all, this technology enables unprecedented NMR sensitivity while encompassing a broad set of nuclei, thus highlighting versatile routes towards a more comprehensive structural characterization of biomolecules at low concentration.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.09.11.751018","type":"posted-content","created":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T20:00:15Z","timestamp":1789761615000},"source":"Crossref","is-referenced-by-count":0,"title":["Efficient Through-Bond Propagation of Nuclear-Spin Hyperpolarization via TOCSY-Enhanced LC-Photo-CIDNP"],"prefix":"10.64898","author":[{"given":"Ji Ho","family":"Jeong","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706 (USA)"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anubhab","family":"Halder","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706 (USA)"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silvia","family":"Cavagnero","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706 (USA)"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026092213400526000_2026.09.11.751018v1.1","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1038\/s41596-023-00921-9","article-title":"Optimal 13C NMR investigation of intrinsically disordered proteins at 1.2 GHz","volume":"19","year":"2024","journal-title":"Nat. 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