{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T12:46:01Z","timestamp":1789908361166,"version":"4.0.1"},"reference-count":38,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2018,1,15]],"date-time":"2018-01-15T00:00:00Z","timestamp":1515974400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>The synthetic peptide PnPP-19 comprehends 19 amino acid residues and it represents part of the primary structure of the toxin \u03b4-CNTX-Pn1c (PnTx2-6), isolated from the venom of the spider Phoneutria nigriventer. Behavioural tests suggest that PnPP-19 induces antinociception by activation of CB1, \u03bc and \u03b4 opioid receptors. Since the peripheral and central antinociception induced by PnPP-19 involves opioid activation, the aim of this work was to identify whether this synthetic peptide could directly activate opioid receptors and investigate the subtype selectivity for \u03bc-, \u03b4- and\/or \u03ba-opioid receptors. Furthermore, we also studied the modulation of calcium influx driven by PnPP-19 in dorsal root ganglion neurons, and analyzed whether this modulation was opioid-mediated. PnPP-19 selectively activates \u03bc-opioid receptors inducing indirectly inhibition of calcium channels and hereby impairing calcium influx in dorsal root ganglion (DRG) neurons. Interestingly, notwithstanding the activation of opioid receptors, PnPP-19 does not induce \u03b2-arrestin2 recruitment. PnPP-19 is the first spider toxin derivative that, among opioid receptors, selectively activates \u03bc-opioid receptors. The lack of \u03b2-arrestin2 recruitment highlights its potential for the design of new improved opioid agonists.<\/jats:p>","DOI":"10.3390\/toxins10010043","type":"journal-article","created":{"date-parts":[[2018,1,15]],"date-time":"2018-01-15T12:30:36Z","timestamp":1516019436000},"page":"43","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["The Peptide PnPP-19, a Spider Toxin Derivative, Activates \u03bc-Opioid Receptors and Modulates Calcium Channels"],"prefix":"10.3390","volume":"10","author":[{"given":"Ana","family":"Freitas","sequence":"first","affiliation":[{"name":"Departamento de Bioqu\u00edmica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0504-5702","authenticated-orcid":false,"given":"Steve","family":"Peigneur","sequence":"additional","affiliation":[{"name":"Toxicology and Pharmacology, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fl\u00e1vio","family":"Macedo","sequence":"additional","affiliation":[{"name":"Departamento de Bioqu\u00edmica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jos\u00e9","family":"Menezes-Filho","sequence":"additional","affiliation":[{"name":"Departamento de Bioqu\u00edmica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul","family":"Millns","sequence":"additional","affiliation":[{"name":"Arthritis Research UK Pain Centre, School of Life Sciences, Queen\u2019s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liciane","family":"Medeiros","sequence":"additional","affiliation":[{"name":"Cell Signaling Research Group, School of Life Sciences, Queen\u2019s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0828-9430","authenticated-orcid":false,"given":"Maria","family":"Arruda","sequence":"additional","affiliation":[{"name":"Cell Signaling Research Group, School of Life Sciences, Queen\u2019s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK"},{"name":"Farmanguinhos, Fiocruz, Brazilian Ministry of Health, Rio de Janeiro 22775-903, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jader","family":"Cruz","sequence":"additional","affiliation":[{"name":"Departamento de Bioqu\u00edmica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicholas","family":"Holliday","sequence":"additional","affiliation":[{"name":"Cell Signaling Research Group, School of Life Sciences, Queen\u2019s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan","family":"Tytgat","sequence":"additional","affiliation":[{"name":"Toxicology and Pharmacology, KU Leuven, 3000 Leuven, Belgium"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gareth","family":"Hathway","sequence":"additional","affiliation":[{"name":"Arthritis Research UK Pain Centre, School of Life Sciences, Queen\u2019s Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria","family":"De Lima","sequence":"additional","affiliation":[{"name":"Departamento de Bioqu\u00edmica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,1,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"De Lima, M.E., Figueiredo, S.G., Matavel, A., Nunes, K.P., da Silva, C.N., de Marco Almeida, F., Ribeiro, M., Diniz, V., do Cordeiro, M.N., and Stankiewicz, M. (2015). Phoneutria nigriventer Venom and Toxins: A Review, Springer.","DOI":"10.1007\/978-94-007-6646-4_6-1"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1016\/j.toxicon.2008.05.020","article-title":"A rational nomenclature for naming peptide toxins from spiders and other venomous animals","volume":"52","author":"King","year":"2008","journal-title":"Toxicon"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1197","DOI":"10.1016\/j.toxicon.2008.02.010","article-title":"Tx2-6 toxin of the Phoneutria nigriventer spider potentiates rat erectile function","volume":"51","author":"Nunes","year":"2008","journal-title":"Toxicon"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"730","DOI":"10.1016\/j.urology.2014.05.030","article-title":"The effect of PnTx2-6 protein from Phoneutria nigriventer spider toxin on improvement of erectile dysfunction in a rat model of cavernous nerve injury","volume":"84","author":"Jung","year":"2014","journal-title":"Urology"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1481","DOI":"10.1016\/j.juro.2015.06.081","article-title":"PnPP-19, a synthetic and non toxic peptide designed from a Phoneutria nigriventer toxin, potentiates erectile function via NO\/cGMP","volume":"194","author":"Silva","year":"2015","journal-title":"J. Urol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1491","DOI":"10.1111\/bph.13448","article-title":"PnPP-19, a spider toxin peptide, induces peripheral antinociception through opioid and cannabinoid receptors and inhibition of neutral endopeptidase","volume":"173","author":"Freitas","year":"2016","journal-title":"Br. J. Pharmacol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.niox.2017.01.004","article-title":"The synthetic peptide PnPP-19 induces peripheral antinociception via activation of NO\/cGMP\/KATP pathway: Role of eNOS and nNOS","volume":"64","author":"Freitas","year":"2017","journal-title":"Nitric Oxide"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1186\/s40409-016-0091-6","article-title":"A spider derived peptide, PnPP-19, induces central antinociception mediated by opioid and cannabinoid systems","volume":"22","author":"Freitas","year":"2016","journal-title":"J. Venom. Anim. Toxins Incl. Trop. Dis."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1177\/204946370900300102","article-title":"The Cost and Burden of Chronic Pain","volume":"3","author":"Phillips","year":"2009","journal-title":"Rev. Pain"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1038\/nature19112","article-title":"Structure-based discovery of opioid analgesics with reduced side effects","volume":"537","author":"Manglik","year":"2016","journal-title":"Nature"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1146\/annurev.pharmtox.40.1.389","article-title":"Molecular mechanisms and regulation of opioid receptor signaling","volume":"40","author":"Law","year":"2000","journal-title":"Annu. Rev. Pharmacol. Toxicol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.pain.2008.07.014","article-title":"Analgesic effect in rodents of native and recombinant Ph\u03b11\u03b2 toxin, a high-voltage-activated calcium channel blocker isolated from armed spider venom","volume":"140","author":"Souza","year":"2008","journal-title":"Pain"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2224","DOI":"10.1016\/j.pain.2011.04.015","article-title":"Antinociceptive effect of Brazilian armed spider venom toxin Tx3-3 in animal models of neuropathic pain","volume":"152","author":"Dalmolin","year":"2011","journal-title":"Pain"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"69","DOI":"10.2147\/nedt.2007.3.1.69","article-title":"Ziconotide: A review of its pharmacology and use in the treatment of pain","volume":"3","author":"McGivern","year":"2007","journal-title":"Neuropsychiatr. Dis. Treat."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Emerich, B.L., Ferreira, R., Cordeiro, M.N., Borges, M.H., Pimenta, A., Figueiredo, S.G., Duarte, I.D.G., and de Lima, M.E. (2016). \u03b4-Ctenitoxin-Pn1a, a Peptide from Phoneutria nigriventer Spider Venom, Shows Antinociceptive Effect Involving Opioid and Cannabinoid Systems, in Rats. Toxins, 8.","DOI":"10.3390\/toxins8040106"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"S105","DOI":"10.36076\/ppj.2008\/11\/S105","article-title":"Opioid complications and side effects","volume":"11","author":"Benyamin","year":"2008","journal-title":"Pain Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1177\/0885066604263918","article-title":"Acute respiratory failure from abused substances","volume":"19","author":"Wilson","year":"2004","journal-title":"J. Intensiv. Care Med."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1195","DOI":"10.1124\/jpet.105.087254","article-title":"Morphine side effects in beta-arrestin 2 knockout mice","volume":"314","author":"Raehal","year":"2005","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"10494","DOI":"10.1523\/JNEUROSCI.22-23-10494.2002","article-title":"Differential mechanisms of morphine antinociceptive tolerance revealed in (beta)arrestin-2 knock-out mice","volume":"22","author":"Bohn","year":"2002","journal-title":"J. Neurosci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2495","DOI":"10.1126\/science.286.5449.2495","article-title":"Enhanced morphine analgesia in mice lacking beta-arrestin 2","volume":"286","author":"Bohn","year":"1999","journal-title":"Science"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"720","DOI":"10.1038\/35047086","article-title":"\u03bc-opioid receptor desensitization by \u03b2-arrestin-2 determines morphine tolerance but not dependence","volume":"408","author":"Bohn","year":"2000","journal-title":"Nature"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"708","DOI":"10.1124\/jpet.112.201616","article-title":"A G protein-biased ligand at the \u03bc-opioid receptor is potently analgesic with reduced gastrointestinal and respiratory dysfunction compared with morphine","volume":"344","author":"DeWire","year":"2013","journal-title":"J. Pharmacol. Exp. Ther."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1829","DOI":"10.1016\/j.pain.2014.06.011","article-title":"Biased agonism of the \u03bc-opioid receptor by TRV130 increases analgesia and reduces on-target adverse effects versus morphine: A randomized, double-blind, placebo-controlled, crossover study in healthy volunteers","volume":"155","author":"Soergel","year":"2014","journal-title":"Pain"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1016\/S0026-895X(25)09397-6","article-title":"Voltage-dependent inhibition of Ca2+ channels in GH3 cells by cloned \u03bc- and \u03b4-opioid receptors","volume":"50","author":"Piros","year":"1996","journal-title":"Mol. Pharmacol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"7608","DOI":"10.1523\/JNEUROSCI.14-12-07608.1994","article-title":"Opioid receptors modulate diverse types of calcium channels in the nucleus tractus solitarius of the rat","volume":"14","author":"Rhim","year":"1994","journal-title":"J. Neurosci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"5487","DOI":"10.1073\/pnas.84.15.5487","article-title":"\u03bc and \u03b4 receptors belong to a family of receptors that are coupled to potassium channels","volume":"84","author":"North","year":"1987","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2954","DOI":"10.1152\/jn.1998.80.6.2954","article-title":"Opioid-activated postsynaptic, inward rectifying potassium currents in whole cell recordings in substantia gelatinosa neurons","volume":"80","author":"Schneider","year":"1998","journal-title":"J. Neurophysiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3551","DOI":"10.1523\/JNEUROSCI.4899-04.2005","article-title":"Spinal G-protein-gated potassium channels contribute in a dose-dependent manner to the analgesic effect of \u03bc- and \u03b4- but not kappa-opioids","volume":"25","author":"Marker","year":"2005","journal-title":"J. Neurosci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1124\/mol.115.101154","article-title":"Voltage-Gated R-Type Calcium Channel Inhibition via Human \u03bc-, \u03b4-, and \u03ba-opioid Receptors Is Voltage-Independently Mediated by G\u03b2\u03b3 Protein Subunits","volume":"89","author":"Berecki","year":"2016","journal-title":"Mol. Pharmacol."},{"key":"ref_30","first-page":"90","article-title":"Activation of \u03bc-opioid receptors inhibits calcium-currents in the vestibular afferent neurons of the rat through a cAMP dependent mechanism","volume":"8","author":"Vega","year":"2014","journal-title":"Front. Cell. Neurosci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/0896-6273(91)90117-I","article-title":"Activation of mu opioid receptors inhibits transient high- and low-threshold Ca2+ currents, but spares a sustained current","volume":"6","author":"Schroeder","year":"1991","journal-title":"Neuron"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4315","DOI":"10.1523\/JNEUROSCI.15-06-04315.1995","article-title":"\u03bc-Opioid receptor activation reduces multiple components of high-threshold calcium current in rat sensory neurons","volume":"15","author":"Rusin","year":"1995","journal-title":"J. Neurosci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1016\/0896-6273(92)90239-A","article-title":"Subunit stoichiometry of a mammalian K+ channel determined by construction of multimeric cDNAs","volume":"9","author":"Liman","year":"1992","journal-title":"Neuron"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2305","DOI":"10.1016\/S0024-3205(00)00820-1","article-title":"Changes in GIRK1\/GIRK2 deactivation kinetics and basal activity in the presence and absence of RGS4","volume":"67","author":"Ulens","year":"2000","journal-title":"Life Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2394","DOI":"10.1523\/JNEUROSCI.08-07-02394.1988","article-title":"Nerve growth factors (NGF, BDNF) enhance axonal regeneration but are not required for survival of adult sensory neurons","volume":"8","author":"Lindsay","year":"1988","journal-title":"J. Neurosci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"C211","DOI":"10.1152\/ajpcell.1977.232.5.C211","article-title":"A low-cost signal averager and data-acquisition device","volume":"232","author":"Bezanilla","year":"1977","journal-title":"Am. J. Physiol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/S0028-3908(98)00173-7","article-title":"Inhibition of receptor-mediated calcium responses by corticotrophin-releasing hormone in the CATH.a cell line","volume":"38","author":"Bundey","year":"1999","journal-title":"Neuropharmacology"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2166","DOI":"10.1021\/acs.bioconjchem.6b00376","article-title":"Identification of a Cyanine-Dye Labeled Peptidic Ligand for Y1R and Y4R, Based upon the Neuropeptide Y C-Terminal Analogue, BVD-15","volume":"27","author":"Liu","year":"2016","journal-title":"Bioconjug. Chem."}],"container-title":["Toxins"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6651\/10\/1\/43\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T14:51:17Z","timestamp":1760194277000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6651\/10\/1\/43"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,1,15]]},"references-count":38,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2018,1]]}},"alternative-id":["toxins10010043"],"URL":"https:\/\/doi.org\/10.3390\/toxins10010043","relation":{},"ISSN":["2072-6651"],"issn-type":[{"value":"2072-6651","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,1,15]]}}}