{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T18:42:27Z","timestamp":1786732947578,"version":"build-2736575974"},"reference-count":42,"publisher":"American Chemical Society (ACS)","issue":"13","license":[{"start":{"date-parts":[[2021,3,23]],"date-time":"2021-03-23T00:00:00Z","timestamp":1616457600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002383","name":"King Saud University","doi-asserted-by":"publisher","award":["RG-1440-126"],"award-info":[{"award-number":["RG-1440-126"]}],"id":[{"id":"10.13039\/501100002383","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2021,4,6]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Vitamin E plays an exemplary role in living organisms. \u03b1-Tocopherol is the most superior and active form of naturally occurring vitamin E that meets the requirements of human beings as it possesses the \u03b1-tocopherol transfer protein (\u03b1-TTP). \u03b1-Tocopherol deficiency can lead to severe anemia, certain cancers, several neurodegenerative and cardiovascular diseases, and most importantly male infertility. As a result of the depletion of its natural sources, researchers have tried to employ metabolic engineering to enhance \u03b1-tocopherol production to meet the human consumption demand. However, the metabolic engineering approach relies on the metabolic flux of a metabolite in its biosynthetic pathway. Analysis of the metabolic flux of a metabolite needs a method that can monitor the \u03b1-tocopherol level in living cells. This study was undertaken to construct a FRET (fluorescence resonance energy transfer)-based nanosensor for monitoring the \u03b1-tocopherol flux in prokaryotic and eukaryotic living cells. The human \u03b1-TTP was sandwiched between a pair of FRET fluorophores to construct the nanosensor, which was denoted as FLIP-\u03b1 (the fluorescence indicator for \u03b1-tocopherol). FLIP-\u03b1 showed excellence in monitoring the \u03b1-tocopherol flux with high specificity. The sensor was examined for its pH stability for physiological applications, where it shows no pH hindrance to its activity. The calculated affinity of this nanosensor was 100 \u03bcM. It monitored the real-time flux of \u03b1-tocopherol in bacterial and yeast cells, proving its biocompatibility in monitoring the \u03b1-tocopherol dynamics in living cells. Being noninvasive, FLIP-\u03b1 provides high temporal and spatial resolutions, which holds an indispensable significance in bioimaging metabolic pathways that are highly compartmentalized.<\/jats:p>","DOI":"10.1021\/acsomega.1c00041","type":"journal-article","created":{"date-parts":[[2021,3,23]],"date-time":"2021-03-23T14:22:38Z","timestamp":1616509358000},"page":"9020-9027","source":"Crossref","is-referenced-by-count":9,"title":["FRET-Based Genetically Encoded Nanosensor for Real-Time\nMonitoring of the Flux of \u03b1\u2011Tocopherol in Living Cells"],"prefix":"10.1021","volume":"6","author":[{"given":"Habiba","family":"Kausar","sequence":"first","affiliation":[{"name":"Aligarh Muslim University , , ,","place":["Aligarh, India, 202002"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ghazala","family":"Ambrin","sequence":"additional","affiliation":[{"name":"Aligarh Muslim University , , ,","place":["Aligarh, India, 202002"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammad K.","family":"Okla","sequence":"additional","affiliation":[{"name":"King Saud University , , ,","place":["Riyadh, Kingdom of Saudi Arabia, 11451"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saud A.","family":"Alamri","sequence":"additional","affiliation":[{"name":"King Saud University , , ,","place":["Riyadh, Kingdom of Saudi Arabia, 11451"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Walid H.","family":"Soufan","sequence":"additional","affiliation":[{"name":"King Saud University , , ,","place":["Riyadh, Kingdom\nof Saudi Arabia, 11451"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5029-6386","authenticated-orcid":true,"given":"Eid I.","family":"Ibrahim","sequence":"additional","affiliation":[{"name":"King Saud University , , ,","place":["Riyadh, Kingdom\nof Saudi Arabia, 11451"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mostafa A.","family":"Abdel-Maksoud","sequence":"additional","affiliation":[{"name":"King Saud University , , ,","place":["Riyadh, Kingdom of Saudi Arabia, 11451"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4099-7338","authenticated-orcid":true,"given":"Altaf","family":"Ahmad","sequence":"additional","affiliation":[{"name":"Aligarh Muslim University , , ,","place":["Aligarh, India, 202002"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2021,3,23]]},"reference":[{"key":"2026081414131999800_cit1","first-page":"1","article-title":"Pathological roles\nof reactive oxygen species and their\ndefence mechanism","volume":"12","author":"Mohammed","year":"2004","journal-title":"Saudi Pharm. 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Exp.\nBiol."},{"key":"2026081414131999800_cit7","doi-asserted-by":"publisher","first-page":"829","DOI":"10.1016\/S0015-0282(02)04948-8","article-title":"Role of\nreactive oxygen species in\nthe pathophysiology of human reproduction","volume":"79","author":"Agarwal","year":"2003","journal-title":"Fertil.\nSteril."},{"key":"2026081414131999800_cit8","doi-asserted-by":"publisher","first-page":"502","DOI":"10.1016\/j.tvjl.2006.06.005","article-title":"Oxidants and antioxidants\nin disease: oxidative stress\nin farm animal","volume":"173","author":"Lykkesfeldt","year":"2007","journal-title":"Vet. J."},{"key":"2026081414131999800_cit9","doi-asserted-by":"publisher","first-page":"2053","DOI":"10.1080\/10408398.2013.812059","article-title":"Antioxidant compounds from vegetable\nmatrices: Biosynthesis,\noccurrence, and extraction systems","volume":"56","author":"Baiano","year":"2016","journal-title":"Crit. Rev.\nFood Sci. Nutr."},{"key":"2026081414131999800_cit10","first-page":"326","article-title":"Plants as natural\nantioxidants","volume":"5","author":"Gupta","year":"2006","journal-title":"Nat. Prod. Rad."},{"key":"2026081414131999800_cit11","doi-asserted-by":"publisher","first-page":"727","DOI":"10.1093\/ajcn\/79.5.727","article-title":"Polyphenols:\nFood sources and bioavailability","volume":"79","author":"Manach","year":"2004","journal-title":"Am. J. 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Res."},{"key":"2026081414131999800_cit20","doi-asserted-by":"publisher","first-page":"99","DOI":"10.3390\/antiox6040099","article-title":"Recent advances in our understanding\nof tocopherol biosynthesis in plants: an overview of key genes, functions,\nand breeding of vitamin E improved crops","volume":"6","author":"Fritsche","year":"2017","journal-title":"Antioxidants"},{"key":"2026081414131999800_cit21","doi-asserted-by":"publisher","first-page":"2634","DOI":"10.2527\/1997.75102634x","article-title":"Vitamin E supplementation of cattle and shelf-life\nof beef for the Japanese market","volume":"75","author":"Sanders","year":"1997","journal-title":"J. Anim. Sci."},{"key":"2026081414131999800_cit22","first-page":"43","article-title":"Vitamin E:\nan important anti-oxidant in the skin","volume":"17","author":"Edwards","year":"2001","journal-title":"Retinoids\nLipid-Soluble Vitam. Clin. 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Biotechnol."},{"key":"2026081414131999800_cit26","doi-asserted-by":"publisher","first-page":"186","DOI":"10.1016\/S0958-1669(99)80033-0","article-title":"Production\nof high-value compounds: carotenoids and vitamin E","volume":"10","author":"Hirschberg","year":"1999","journal-title":"Curr. Opin. Biotechnol."},{"key":"2026081414131999800_cit27","doi-asserted-by":"publisher","first-page":"321","DOI":"10.1104\/pp.010747","article-title":"Isolation and characterization\nof homogentisate phytyltransferase genes from Synechocystis sp. 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Plant Biol."},{"key":"2026081414131999800_cit30","doi-asserted-by":"publisher","first-page":"288","DOI":"10.3390\/antiox9040288","article-title":"Metabolic Flux Analysis\nof Catechin Biosynthesis Pathways Using Nanosensor","volume":"9","author":"Kausar","year":"2020","journal-title":"Antioxidants"},{"key":"2026081414131999800_cit31","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1186\/s12951-016-0204-y","article-title":"Designing,\nconstruction and characterization\nof genetically encoded FRET-based nanosensor for real time monitoring\nof lysine flux in living cells","volume":"14","author":"Ameen","year":"2016","journal-title":"J. Nanobiotechnol."},{"key":"2026081414131999800_cit32","doi-asserted-by":"publisher","DOI":"10.3791\/51657","article-title":"Glutamine flux imaging using genetically\nencoded sensors","volume":"89","author":"Besnard","year":"2014","journal-title":"J. Vis. Exp."},{"key":"2026081414131999800_cit33","doi-asserted-by":"publisher","first-page":"9846","DOI":"10.1073\/pnas.142089199","article-title":"Visualization of maltose uptake in\nliving yeast cells by fluorescent nanosensors","volume":"99","author":"Fehr","year":"2002","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"2026081414131999800_cit34","doi-asserted-by":"publisher","DOI":"10.1038\/srep43479","article-title":"A genetically encoded\ntoolkit for tracking live-cell histidine dynamics in space and time","volume":"7","author":"Hu","year":"2017","journal-title":"Sci. Rep."},{"key":"2026081414131999800_cit35","doi-asserted-by":"publisher","first-page":"1412","DOI":"10.1002\/pro.2721","article-title":"Construction of\na robust and sensitive arginine biosensor through ancestral protein\nreconstruction","volume":"24","author":"Whitfield","year":"2015","journal-title":"Protein Sci."},{"key":"2026081414131999800_cit36","doi-asserted-by":"publisher","first-page":"866","DOI":"10.1016\/j.snb.2017.11.030","article-title":"Live cell imaging of vitamin B12 dynamics by genetically encoded\nfluorescent nanosensor","volume":"257","author":"Ahmad","year":"2018","journal-title":"Sens. Actuators, B"},{"key":"2026081414131999800_cit37","doi-asserted-by":"publisher","first-page":"603","DOI":"10.1023\/B:JOFL.0000039347.94943.99","article-title":"Live imaging of\nglucose homeostasis in nuclei of COS-7 cells","volume":"14","author":"Fehr","year":"2004","journal-title":"J. Fluoresc."},{"key":"2026081414131999800_cit38","doi-asserted-by":"publisher","first-page":"437","DOI":"10.1042\/bj3060437","article-title":"Human \u03b1-tocopherol\ntransfer protein: cDNA cloning, expression and chromosomal localization","volume":"306","author":"Arita","year":"1995","journal-title":"Biochem. J."},{"key":"2026081414131999800_cit39","doi-asserted-by":"publisher","first-page":"925","DOI":"10.1007\/s00335-001-2073-3","article-title":"Genomic characterization\nof human SEC14L1 splice variants\nwithin a 17q25 candidate tumor suppressor gene region and identification\nof an unrelated embedded expressed sequence tag","volume":"12","author":"Kalikin","year":"2001","journal-title":"Mamm. Genome"},{"key":"2026081414131999800_cit40","doi-asserted-by":"publisher","first-page":"725","DOI":"10.1016\/S0022-2836(03)00724-1","article-title":"The molecular\nbasis of vitamin E retention: structure of human \u03b1-tocopherol\ntransfer protein","volume":"331","author":"Meier","year":"2003","journal-title":"J. Mol. Biol."},{"key":"2026081414131999800_cit41","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1038\/nbt0102-87","article-title":"A variant of yellow\nfluorescent protein with fast and\nefficient maturation for cell-biological applications","volume":"20","author":"Nagai","year":"2002","journal-title":"Nat. Biotechnol."},{"key":"2026081414131999800_cit42","doi-asserted-by":"publisher","first-page":"993","DOI":"10.1038\/nmeth.4045","article-title":"Fluorescent indicators\nfor simultaneous reporting of all four cell cycle phases","volume":"13","author":"Bajar","year":"2016","journal-title":"Nat. Methods"}],"container-title":["ACS Omega"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acsomega.1c00041","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/6\/13\/9020\/13097249\/ao1c00041.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/6\/13\/9020\/13097249\/ao1c00041.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T18:24:26Z","timestamp":1786731866000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/acsodf\/article\/6\/13\/9020\/490369\/FRET-Based-Genetically-Encoded-Nanosensor-for-Real"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,23]]},"references-count":42,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2021,3,23]]},"published-print":{"date-parts":[[2021,4,6]]}},"URL":"https:\/\/doi.org\/10.1021\/acsomega.1c00041","relation":{},"ISSN":["2470-1343"],"issn-type":[{"value":"2470-1343","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,23]]}}}