{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T11:23:51Z","timestamp":1772191431000,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,12,16]],"date-time":"2020-12-16T00:00:00Z","timestamp":1608076800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"publisher","award":["19-74-30014"],"award-info":[{"award-number":["19-74-30014"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Recently developed fluorescent protein-scorpion toxin chimeras (FP-Tx) show blocking activities for potassium voltage-gated channels of Kv1 family and retain almost fully pharmacological profiles of the parental peptide toxins (Kuzmenkov et al., Sci Rep. 2016, 6, 33314). Here we report on N-terminally green fluorescent protein (GFP)-tagged agitoxin 2 (GFP-L2-AgTx2) with high affinity and selectivity for the binding site of Kv1.3 channel involved in the pathogenesis of various (primarily of autoimmune origin) diseases. The basis for this selectivity relates to N-terminal location of GFP, since transposition of GFP to the C-terminus of AgTx2 recovered specific interactions with the Kv1.1 and Kv1.6 binding sites. Competitive binding experiments revealed that the binding site of GFP-L2-AgTx2 overlaps that of charybdotoxin, kaliotoxin 1, and agitoxin 2, the known Kv1.3-channel pore blockers. GFP-L2-AgTx2 was demonstrated to be applicable as a fluorescent probe to search for Kv1.3 pore blockers among individual compounds and in complex mixtures, to measure blocker affinities, and to visualize Kv1.3 distribution at the plasma membrane of Kv1.3-expressing HEK293 cells. Our studies show that definite combinations of fluorescent proteins and peptide blockers can result in considerable modulation of the natural blocker-channel binding profile yielding selective fluorescent ligands of certain channels.<\/jats:p>","DOI":"10.3390\/toxins12120802","type":"journal-article","created":{"date-parts":[[2020,12,16]],"date-time":"2020-12-16T22:12:06Z","timestamp":1608156726000},"page":"802","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["N-Terminal Tagging with GFP Enhances Selectivity of Agitoxin 2 to Kv1.3-Channel Binding Site"],"prefix":"10.3390","volume":"12","author":[{"given":"Oksana V.","family":"Nekrasova","sequence":"first","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1386-5922","authenticated-orcid":false,"given":"Alexandra L.","family":"Primak","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"},{"name":"Biological Faculty, Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anastasia A.","family":"Ignatova","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4090-4859","authenticated-orcid":false,"given":"Valery N.","family":"Novoseletsky","sequence":"additional","affiliation":[{"name":"Biological Faculty, Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olga V.","family":"Geras\u2019kina","sequence":"additional","affiliation":[{"name":"Biological Faculty, Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ksenia S.","family":"Kudryashova","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"},{"name":"Biological Faculty, Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sergey A.","family":"Yakimov","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mikhail P.","family":"Kirpichnikov","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"},{"name":"Biological Faculty, Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alexander S.","family":"Arseniev","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1596-9506","authenticated-orcid":false,"given":"Alexey V.","family":"Feofanov","sequence":"additional","affiliation":[{"name":"Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16\/10, 117997 Moscow, Russia"},{"name":"Biological Faculty, Lomonosov Moscow State University, Leninskie Gory 1, 119992 Moscow, Russia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/bs.apha.2017.03.001","article-title":"Modulation of ion channels by cysteine-rich peptides","volume":"79","author":"Mobli","year":"2017","journal-title":"Adv. Pharmacol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1080\/17460441.2017.1317243","article-title":"Enhancing the therapeutic potential of peptide toxins","volume":"12","author":"Norton","year":"2017","journal-title":"Expert Opin. 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Graph."}],"container-title":["Toxins"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6651\/12\/12\/802\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:45:50Z","timestamp":1760179550000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6651\/12\/12\/802"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12,16]]},"references-count":32,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2020,12]]}},"alternative-id":["toxins12120802"],"URL":"https:\/\/doi.org\/10.3390\/toxins12120802","relation":{},"ISSN":["2072-6651"],"issn-type":[{"value":"2072-6651","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12,16]]}}}