{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,15]],"date-time":"2026-02-15T08:54:26Z","timestamp":1771145666064,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2020,5,22]],"date-time":"2020-05-22T00:00:00Z","timestamp":1590105600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["AI070494"],"award-info":[{"award-number":["AI070494"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["CA168517"],"award-info":[{"award-number":["CA168517"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["NS107479"],"award-info":[{"award-number":["NS107479"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["CA242620"],"award-info":[{"award-number":["CA242620"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"name":"60Degreepharma","award":["MP_AS_60DP"],"award-info":[{"award-number":["MP_AS_60DP"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Processing of certain viral proteins and bacterial toxins by host serine proteases is a frequent and critical step in virulence. The coronavirus spike glycoprotein contains three (S1, S2, and S2\u2032) cleavage sites that are processed by human host proteases. The exact nature of these cleavage sites, and their respective processing proteases, can determine whether the virus can cross species and the level of pathogenicity. Recent comparisons of the genomes of the highly pathogenic SARS-CoV2 and MERS-CoV, with less pathogenic strains (e.g., Bat-RaTG13, the bat homologue of SARS-CoV2) identified possible mutations in the receptor binding domain and in the S1 and S2\u2032 cleavage sites of their spike glycoprotein. However, there remains some confusion on the relative roles of the possible serine proteases involved for priming. Using anthrax toxin as a model system, we show that in vivo inhibition of priming by pan-active serine protease inhibitors can be effective at suppressing toxicity. Hence, our studies should encourage further efforts in developing either pan-serine protease inhibitors or inhibitor cocktails to target SARS-CoV2 and potentially ward off future pandemics that could develop because of additional mutations in the S-protein priming sequence in coronaviruses.<\/jats:p>","DOI":"10.3390\/molecules25102424","type":"journal-article","created":{"date-parts":[[2020,5,22]],"date-time":"2020-05-22T10:18:18Z","timestamp":1590142698000},"page":"2424","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Potential Therapeutic Targeting of Coronavirus Spike Glycoprotein Priming"],"prefix":"10.3390","volume":"25","author":[{"given":"Elisa","family":"Barile","sequence":"first","affiliation":[{"name":"Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Carlo","family":"Baggio","sequence":"additional","affiliation":[{"name":"Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luca","family":"Gambini","sequence":"additional","affiliation":[{"name":"Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sergey A.","family":"Shiryaev","sequence":"additional","affiliation":[{"name":"Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alex Y.","family":"Strongin","sequence":"additional","affiliation":[{"name":"Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5179-470X","authenticated-orcid":false,"given":"Maurizio","family":"Pellecchia","sequence":"additional","affiliation":[{"name":"Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, CA 92521, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Wrapp, D., Wang, N., Corbett, K.S., Goldsmith, J.A., Hsieh, C.L., Abiona, O., Graham, B.S., and McLellan, J.S. (2020). Cryo-EM structure of the 2019-nCoV spike in the prefusion conformation. Science.","DOI":"10.1101\/2020.02.11.944462"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"15214","DOI":"10.1073\/pnas.1407087111","article-title":"Host cell entry of Middle East respiratory syndrome coronavirus after two-step, furin-mediated activation of the spike protein","volume":"111","author":"Millet","year":"2014","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"104742","DOI":"10.1016\/j.antiviral.2020.104742","article-title":"The spike glycoprotein of the new coronavirus 2019-nCoV contains a furin-like cleavage site absent in CoV of the same clade","volume":"176","author":"Coutard","year":"2020","journal-title":"Antiviral Res."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Hoffmann, M., Kleine-Weber, H., Schroeder, S., Kruger, N., Herrler, T., Erichsen, S., Schiergens, T.S., Herrler, G., Wu, N.H., and Nitsche, A. (2020). SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell.","DOI":"10.1016\/j.cell.2020.02.052"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"140","DOI":"10.1016\/S1473-3099(13)70690-X","article-title":"Middle East respiratory syndrome coronavirus in dromedary camels: An outbreak investigation","volume":"14","author":"Haagmans","year":"2014","journal-title":"Lancet Infect. Dis."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1038\/nature12711","article-title":"Isolation and characterization of a bat SARS-like coronavirus that uses the ACE2 receptor","volume":"503","author":"Ge","year":"2013","journal-title":"Nature"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"468","DOI":"10.1016\/j.tim.2015.06.003","article-title":"Bat-to-human: Spike features determining \u2018host jump\u2019 of coronaviruses SARS-CoV, MERS-CoV, and beyond","volume":"23","author":"Lu","year":"2015","journal-title":"Trends Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.virusres.2014.11.021","article-title":"Host cell proteases: Critical determinants of coronavirus tropism and pathogenesis","volume":"202","author":"Millet","year":"2015","journal-title":"Virus Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"20897","DOI":"10.1074\/jbc.M803762200","article-title":"Substrate cleavage analysis of furin and related proprotein convertases. A comparative study","volume":"283","author":"Remacle","year":"2008","journal-title":"J. Biol. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1016\/j.tips.2005.04.006","article-title":"Cutting back on pro-protein convertases: The latest approaches to pharmacological inhibition","volume":"26","author":"Fugere","year":"2005","journal-title":"Trends Pharmacol. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"753","DOI":"10.1038\/nrm934","article-title":"Furin at the cutting edge: From protein traffic to embryogenesis and disease","volume":"3","author":"Thomas","year":"2002","journal-title":"Nat. Rev. Mol. Cell Biol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"16597","DOI":"10.1038\/s41598-018-34859-w","article-title":"Functional analysis of potential cleavage sites in the MERS-coronavirus spike protein","volume":"8","author":"Elzayat","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Matsuyama, S., Shirato, K., Kawase, M., Terada, Y., Kawachi, K., Fukushi, S., and Kamitani, W. (2018). Middle East Respiratory Syndrome Coronavirus Spike Protein Is Not Activated Directly by Cellular Furin during Viral Entry into Target Cells. J. Virol., 92.","DOI":"10.1128\/JVI.00683-18"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"5175","DOI":"10.1128\/IAI.00719-07","article-title":"Anthrax protective antigen cleavage and clearance from the blood of mice and rats","volume":"75","author":"Moayeri","year":"2007","journal-title":"Infect. Immun."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4374","DOI":"10.1016\/j.vaccine.2004.01.069","article-title":"Expression of Bacillus anthracis protective antigen in transgenic chloroplasts of tobacco, a non-food\/feed crop","volume":"22","author":"Watson","year":"2004","journal-title":"Vaccine"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1016\/j.bbrc.2004.07.012","article-title":"Cross-inhibition between furin and lethal factor inhibitors","volume":"321","author":"Peinado","year":"2004","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_17","first-page":"6061","article-title":"Tumor cell-selective cytotoxicity of matrix metalloproteinase-activated anthrax toxin","volume":"60","author":"Liu","year":"2000","journal-title":"Cancer Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1853","DOI":"10.1128\/IAI.67.4.1853-1859.1999","article-title":"Oligomerization of anthrax toxin protective antigen and binding of lethal factor during endocytic uptake into mammalian cells","volume":"67","author":"Singh","year":"1999","journal-title":"Infect. Immun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"3370","DOI":"10.1128\/iai.65.8.3370-3375.1997","article-title":"A role for PACE4 in the proteolytic activation of anthrax toxin protective antigen","volume":"65","author":"Gordon","year":"1997","journal-title":"Infect. Immun."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1006\/abbi.1995.1002","article-title":"In vitro processing of anthrax toxin protective antigen by recombinant PC1 (SPC3) and bovine intermediate lobe secretory vesicle membranes","volume":"316","author":"Friedman","year":"1995","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1128\/iai.63.1.82-87.1995","article-title":"Proteolytic activation of bacterial toxins by eukaryotic cells is performed by furin and by additional cellular proteases","volume":"63","author":"Gordon","year":"1995","journal-title":"Infect. Immun."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"29039","DOI":"10.1016\/S0021-9258(19)62010-7","article-title":"The chymotrypsin-sensitive site, FFD315, in anthrax toxin protective antigen is required for translocation of lethal factor","volume":"269","author":"Singh","year":"1994","journal-title":"J. Biol. Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3334","DOI":"10.1016\/S0021-9258(18)53698-X","article-title":"Residues 1-254 of anthrax toxin lethal factor are sufficient to cause cellular uptake of fused polypeptides","volume":"268","author":"Arora","year":"1993","journal-title":"J. Biol. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"10277","DOI":"10.1073\/pnas.89.21.10277","article-title":"Anthrax toxin protective antigen is activated by a cell surface protease with the sequence specificity and catalytic properties of furin","volume":"89","author":"Klimpel","year":"1992","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"16396","DOI":"10.1016\/S0021-9258(18)42016-9","article-title":"Human furin is a calcium-dependent serine endoprotease that recognizes the sequence Arg-X-X-Arg and efficiently cleaves anthrax toxin protective antigen","volume":"267","author":"Molloy","year":"1992","journal-title":"J. Biol. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1016\/j.humpath.2004.11.006","article-title":"Immunohistochemical, in situ hybridization, and ultrastructural localization of SARS-associated coronavirus in lung of a fatal case of severe acute respiratory syndrome in Taiwan","volume":"36","author":"Shieh","year":"2005","journal-title":"Hum. Pathol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1093\/protein\/gzh013","article-title":"Prediction of proprotein convertase cleavage sites","volume":"17","author":"Duckert","year":"2004","journal-title":"Protein Eng. Des. Sel."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Letko, M., Marzi, A., and Munster, V. (2020). Functional assessment of cell entry and receptor usage for SARS-CoV-2 and other lineage B betacoronaviruses. Nat. Microbiol.","DOI":"10.1101\/2020.01.22.915660"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Barre, O., Dufour, A., Eckhard, U., Kappelhoff, R., Beliveau, F., Leduc, R., and Overall, C.M. (2014). Cleavage specificity analysis of six type II transmembrane serine proteases (TTSPs) using PICS with proteome-derived peptide libraries. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0105984"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1113","DOI":"10.1021\/cb500087x","article-title":"X-ray structures of human furin in complex with competitive inhibitors","volume":"9","author":"Dahms","year":"2014","journal-title":"ACS Chem. Biol."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Gupta, P.K., Moayeri, M., Crown, D., Fattah, R.J., and Leppla, S.H. (2008). Role of N-terminal amino acids in the potency of anthrax lethal factor. PLoS ONE, 3.","DOI":"10.1371\/journal.pone.0003130"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"20847","DOI":"10.1074\/jbc.M703847200","article-title":"Targeting host cell furin proprotein convertases as a therapeutic strategy against bacterial toxins and viral pathogens","volume":"282","author":"Shiryaev","year":"2007","journal-title":"J. Biol. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"11518","DOI":"10.1038\/s41598-018-29944-z","article-title":"Evolution of high pathogenicity of H5 avian influenza virus: Haemagglutinin cleavage site selection of reverse-genetics mutants during passage in chickens","volume":"8","author":"Luczo","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4439","DOI":"10.1128\/JVI.75.9.4439-4443.2001","article-title":"Generation of a highly pathogenic avian influenza A virus from an avirulent field isolate by passaging in chickens","volume":"75","author":"Ito","year":"2001","journal-title":"J. Virol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Walls, A.C., Park, Y.J., Tortorici, M.A., Wall, A., McGuire, A.T., and Veesler, D. (2020). Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell.","DOI":"10.1101\/2020.02.19.956581"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"673","DOI":"10.1002\/cmdc.201800807","article-title":"Design, Synthesis, and Characterization of Macrocyclic Inhibitors of the Proprotein Convertase Furin","volume":"14","author":"Ivanova","year":"2019","journal-title":"ChemMedChem"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1953","DOI":"10.1002\/cmdc.201700596","article-title":"Optimization of Substrate-Analogue Furin Inhibitors","volume":"12","author":"Ivanova","year":"2017","journal-title":"ChemMedChem"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5","DOI":"10.15407\/ubj88.06.005","article-title":"Chemical structure and properties of low-molecular furin inhibitors","volume":"88","author":"Osadchuk","year":"2016","journal-title":"Ukr. Biochem. J."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1218","DOI":"10.1002\/cmdc.201500103","article-title":"Novel Furin Inhibitors with Potent Anti-infectious Activity","volume":"10","author":"Hardes","year":"2015","journal-title":"ChemMedChem"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1517\/13543776.2014.1000303","article-title":"Therapeutic uses of furin and its inhibitors: A patent review","volume":"25","author":"Couture","year":"2015","journal-title":"Expert Opin. Ther. Pat."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"7958","DOI":"10.1073\/pnas.0502159102","article-title":"Anthrax lethal factor inhibition","volume":"102","author":"Shoop","year":"2005","journal-title":"Proc. Natl. Acad. Sci. USA"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/10\/2424\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:31:29Z","timestamp":1760175089000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/25\/10\/2424"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,5,22]]},"references-count":41,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2020,5]]}},"alternative-id":["molecules25102424"],"URL":"https:\/\/doi.org\/10.3390\/molecules25102424","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,5,22]]}}}