{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T17:11:54Z","timestamp":1781889114237,"version":"3.54.5"},"reference-count":28,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2022,5,28]],"date-time":"2022-05-28T00:00:00Z","timestamp":1653696000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Slovenian Research Agency Programme","award":["P1-0207"],"award-info":[{"award-number":["P1-0207"]}]},{"name":"Slovenian Research Agency Programme","award":["P3-0108"],"award-info":[{"award-number":["P3-0108"]}]},{"name":"Slovenian Research Agency Programme","award":["1000-17-0106-6"],"award-info":[{"award-number":["1000-17-0106-6"]}]},{"name":"Young Researcher","award":["P1-0207"],"award-info":[{"award-number":["P1-0207"]}]},{"name":"Young Researcher","award":["P3-0108"],"award-info":[{"award-number":["P3-0108"]}]},{"name":"Young Researcher","award":["1000-17-0106-6"],"award-info":[{"award-number":["1000-17-0106-6"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>\u03b2-Neurotoxins are secreted phospholipase A2 molecules that inhibit transmission in neuromuscular synapses by poisoning the motor neurons. These toxins specifically and rapidly internalise into the nerve endings of motor neurons. Ammodytoxin (Atx) is a prototype \u03b2-neurotoxin from the venom of the nose-horned viper (Vipera ammodytes ammodytes). Here, we studied the relevance of the enzymatic activity of Atx in cell internalisation and subsequent intracellular movement using transmission electron microscopy (TEM). We prepared a recombinant, enzymatically inactive mutant of Atx, Atx(D49S), labelled with gold nanoparticles (GNP), and incubated this with PC12 cells, to analyse its localisation by TEM. Atx(D49S)-GNP internalised into the cells. Inside the cells, Atx(D49S)-GNP was detected in different vesicle-like structures, cytosol, endoplasmic reticulum and mitochondria, where it was spotted in the intermembrane space and matrix. Co-localization of fluorescently labelled Atx(D49S) with mitochondria in PC12 cells by confocal fluorescence microscopy confirmed the reliability of results generated using Atx(D49S)-GNP and TEM and allowed us to conclude that the phospholipase activity of Atx is not obligatory for its cell internalisation and translocation into the mitochondrial intermembrane space and matrix.<\/jats:p>","DOI":"10.3390\/toxins14060375","type":"journal-article","created":{"date-parts":[[2022,5,31]],"date-time":"2022-05-31T05:25:42Z","timestamp":1653974742000},"page":"375","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["The Phospholipase Activity of Ammodytoxin, a Prototype Snake Venom \u03b2-Neurotoxin, Is Not Obligatory for Cell Internalisation and Translocation to Mitochondria"],"prefix":"10.3390","volume":"14","author":[{"given":"Adrijan","family":"Ivanu\u0161ec","sequence":"first","affiliation":[{"name":"Department of Molecular and Biomedical Sciences, Jo\u017eef Stefan Institute, SI-1000 Ljubljana, Slovenia"},{"name":"Doctoral School, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0646-5602","authenticated-orcid":false,"given":"Jernej","family":"\u0160ribar","sequence":"additional","affiliation":[{"name":"Department of Molecular and Biomedical Sciences, Jo\u017eef Stefan Institute, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1999-9988","authenticated-orcid":false,"given":"Peter","family":"Verani\u010d","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Institute of Cell Biology, University of Ljubljana, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0203-0708","authenticated-orcid":false,"given":"Igor","family":"Kri\u017eaj","sequence":"additional","affiliation":[{"name":"Department of Molecular and Biomedical Sciences, Jo\u017eef Stefan Institute, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6130","DOI":"10.1021\/cr200085w","article-title":"Phospholipase A2 enzymes: Physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention","volume":"111","author":"Dennis","year":"2011","journal-title":"Chem. 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