{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,24]],"date-time":"2026-01-24T03:15:02Z","timestamp":1769224502377,"version":"3.49.0"},"reference-count":29,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2017,1,7]],"date-time":"2017-01-07T00:00:00Z","timestamp":1483747200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science and Technology, Taiwan, ROC","award":["MOST 104-2320-B110-002-MY2"],"award-info":[{"award-number":["MOST 104-2320-B110-002-MY2"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>This study presents an adenosine (A)-based molecular beacon (MB) for selective detection of Naja atra cardiotoxin (CTX) that functions by utilizing the competitive binding between CTX and the poly(A) stem of MB to coralyne. The 5\u2032- and 3\u2032-end of MB were labeled with a reporter fluorophore and a non-fluorescent quencher, respectively. Coralyne induced formation of the stem-loop MB structure through A2-coralyne-A2 coordination, causing fluorescence signal turn-off due to fluorescence resonance energy transfer between the fluorophore and quencher. CTX3 could bind to coralyne. Moreover, CTX3 alone induced the folding of MB structure and quenching of MB fluorescence. Unlike that of snake venom \u03b1-neurotoxins, the fluorescence signal of coralyne-MB complexes produced a bell-shaped concentration-dependent curve in the presence of CTX3 and CTX isotoxins; a turn-on fluorescence signal was noted when CTX concentration was \u226480 nM, while a turn-off fluorescence signal was noted with a further increase in toxin concentrations. The fluorescence signal of coralyne-MB complexes yielded a bell-shaped curve in response to varying concentrations of N. atra crude venom but not those of Bungarus multicinctus and Protobothrops mucrosquamatus venoms. Moreover, N. nigricollis venom also functioned as N. atra venom to yield a bell-shaped concentration-dependent curve of MB fluorescence signal, again supporting that the hairpin-shaped MB could detect crude venoms containing CTXs. Taken together, our data validate that a platform composed of coralyne-induced stem-loop MB structure selectively detects CTXs.<\/jats:p>","DOI":"10.3390\/toxins9010024","type":"journal-article","created":{"date-parts":[[2017,1,9]],"date-time":"2017-01-09T11:03:23Z","timestamp":1483959803000},"page":"24","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Detection of Naja atra Cardiotoxin Using Adenosine-Based Molecular Beacon"],"prefix":"10.3390","volume":"9","author":[{"given":"Yi-Jun","family":"Shi","sequence":"first","affiliation":[{"name":"Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ying-Jung","family":"Chen","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wan-Ping","family":"Hu","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Long-Sen","family":"Chang","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan"},{"name":"Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,1,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3036","DOI":"10.1039\/C5CS00020C","article-title":"Rationally designed molecular beacons for bioanalytical and biomedical applications","volume":"44","author":"Zheng","year":"2015","journal-title":"Chem. Soc. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1515\/chempap-2015-0026","article-title":"Biosensors based on molecular beacons","volume":"69","author":"Stobiecka","year":"2015","journal-title":"Chem. Pap."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"187","DOI":"10.3109\/15563650.2014.887725","article-title":"Rapid diagnosis of Naja atra snakebites","volume":"52","author":"Hung","year":"2014","journal-title":"Clin. Toxicol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"17869","DOI":"10.1074\/jbc.274.25.17869","article-title":"Binding of nucleotide triphosphates to cardiotoxin analogue II from the Taiwan cobra venom (Naja naja atra). Elucidation of the structural interactions in the dATP-cardiotoxin analogue II complex","volume":"274","author":"Jayaraman","year":"1999","journal-title":"J. Biol. Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"16067","DOI":"10.1021\/bi992070s","article-title":"Sequence and structural selectivity of nucleic acid binding ligands","volume":"38","author":"Ren","year":"1999","journal-title":"Biochemistry"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4607","DOI":"10.1039\/c3cc40976g","article-title":"Adenosine-based molecular beacons as light-up probes for sensing heparin in plasma","volume":"49","author":"Kuo","year":"2013","journal-title":"Chem. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"8644","DOI":"10.1021\/ja0492891","article-title":"Assembly of an antiparallel homo-adenine DNA duplex by small-molecule binding","volume":"126","author":"Persil","year":"2004","journal-title":"J. Am. Chem. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5035","DOI":"10.1016\/j.febslet.2005.07.091","article-title":"Molecular recognition of nucleic acids: Coralyne binds strongly to poly(A)","volume":"579","author":"Xing","year":"2005","journal-title":"FEBS Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1093\/protein\/1.1.37","article-title":"The crystal structure of \u03b1-bungarotoxin at 2.5 \u00c5 resolution: Relation to solution structure and binding to acetylcholine receptor","volume":"1","author":"Love","year":"1986","journal-title":"Protein Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2131","DOI":"10.1021\/bi00060a002","article-title":"Solution conformation of cobrotoxin: A nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing study","volume":"32","author":"Yu","year":"1993","journal-title":"Biochemistry"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1046\/j.1432-1327.1999.00623.x","article-title":"Snake venom \u03b1-neurotoxins and other \u2018three-finger\u2019 proteins","volume":"264","author":"Tsetlin","year":"1999","journal-title":"Eur. J. Biochem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1110\/ps.9.4.637","article-title":"Elucidation of the solution structure of cardiotoxin analogue V from the Taiwan cobra (Naja atra), identification of structural features important for the lethal action of snake venom cardiotoxins","volume":"9","author":"Jayaraman","year":"2000","journal-title":"Protein Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1002\/jccs.199900048","article-title":"Biochemistry and molecular biology of snake neurotoxin","volume":"46","author":"Yang","year":"1999","journal-title":"J. Chin. Chem. Soc."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3970","DOI":"10.1093\/nar\/27.20.3970","article-title":"Genetic organization of \u03b1-bungarotoxins from Bungarus multicinctus (Taiwan banded krait): Evidence showing that the production of \u03b1-bungarotoxin isotoxins is not derived from edited mRNAs","volume":"27","author":"Chang","year":"1999","journal-title":"Nucleic Acids Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1080\/15569540701209716","article-title":"Genetic diversity in snake venom three-finger proteins and phospholipase A2 enzymes","volume":"26","author":"Chang","year":"2007","journal-title":"Toxins Rev."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"756","DOI":"10.1006\/bbrc.1997.7549","article-title":"Genomic structures of cardiotoxin 4 and cobrotoxin from Naja naja atra (Taiwan cobra)","volume":"239","author":"Chang","year":"1997","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1252","DOI":"10.1093\/oxfordjournals.jbchem.a021889","article-title":"A novel neurotoxin, cobrotoxin b, from Naja naja atra (Taiwan cobra) venom: Purification, characterization, and gene organization","volume":"122","author":"Chang","year":"1997","journal-title":"J. Biochem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"11134","DOI":"10.1039\/c1cc14429d","article-title":"Fluorescence detection of coralyne and polyadenylation reaction using an oligonucleotide-based fluorogenic probe","volume":"47","author":"Lin","year":"2011","journal-title":"Chem. Commun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2865","DOI":"10.1021\/bi00684a012","article-title":"The complete covalent structure of a cardiotoxin from the venom of Naja nigricollis (African black-necked spitting cobra)","volume":"14","author":"Fryklund","year":"1975","journal-title":"Biochemistry"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Chen, Y.J., Tsai, C.Y., Hu, W.P., and Chang, L.S. (2016). Aptamers against Taiwan banded krait \u03b1-bungarotoxin recognize Taiwan cobra cardiotoxins. Toxins, 8.","DOI":"10.3390\/toxins8030066"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1038\/nrd3141","article-title":"Aptamers as therapeutics","volume":"9","author":"Keefe","year":"2010","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"612","DOI":"10.3390\/s120100612","article-title":"Aptamers and their biological applications","volume":"12","author":"Song","year":"2012","journal-title":"Sensors"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"i215","DOI":"10.1093\/bioinformatics\/bts210","article-title":"Identification of sequence-structure RNA binding motifs for SELEX-derived aptamers","volume":"28","author":"Hoinka","year":"2012","journal-title":"Bioinformatics"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"434","DOI":"10.1093\/nar\/gks979","article-title":"The RNA-binding domain of influenzavirus non-structural protein-1 cooperatively binds to virus-specific RNA sequences in a structure-dependent manner","volume":"41","author":"Marc","year":"2013","journal-title":"Nucleic Acids Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1016\/S0041-0101(02)00336-7","article-title":"The clinical significance of venom detection in patients of cobra snakebite","volume":"41","author":"Hung","year":"2003","journal-title":"Toxicon"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1016\/j.chemosphere.2011.12.079","article-title":"Investigations on the interaction of the phototoxic alkaloid coralyne with serum albumins","volume":"87","author":"Khan","year":"2012","journal-title":"Chemosphere"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1023\/A:1014520126856","article-title":"Separation and structure-function studies of Taiwan cobra cardiotoxins","volume":"21","author":"Lin","year":"2002","journal-title":"J. Protein Chem."},{"key":"ref_28","first-page":"529","article-title":"Structural factors affect the interaction of anticardiotoxin antibodies and cobra venom cardiotoxins","volume":"44","author":"Chang","year":"1998","journal-title":"Biochem. Mol. Biol. Int."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.toxicon.2011.04.021","article-title":"Membrane-damaging activity of Taiwan cobra cardiotoxin 3 is responsible for its bactericidal activity","volume":"58","author":"Chen","year":"2011","journal-title":"Toxicon"}],"container-title":["Toxins"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6651\/9\/1\/24\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:25:41Z","timestamp":1760207141000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6651\/9\/1\/24"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,1,7]]},"references-count":29,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2017,1]]}},"alternative-id":["toxins9010024"],"URL":"https:\/\/doi.org\/10.3390\/toxins9010024","relation":{},"ISSN":["2072-6651"],"issn-type":[{"value":"2072-6651","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,1,7]]}}}