{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T18:38:44Z","timestamp":1778870324144,"version":"3.51.4"},"reference-count":50,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,1,27]],"date-time":"2022-01-27T00:00:00Z","timestamp":1643241600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Foundation of South Africa","award":["grant no. 137965"],"award-info":[{"award-number":["grant no. 137965"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>In this contribution, we report on the possibility that cryptococcal protease(s) could activate the SARS-CoV-2 spike (S) protein. The S protein is documented to have a unique four-amino-acid sequence (underlined, SPRRAR\u2193S) at the interface between the S1 and S2 sites, that serves as a cleavage site for the human protease, furin. We compared the biochemical efficiency of cryptococcal protease(s) and furin to mediate the proteolytic cleavage of the S1\/S2 site in a fluorogenic peptide. We show that cryptococcal protease(s) processes this site in a manner comparable to the efficiency of furin (p &gt; 0.581). We conclude the paper by discussing the impact of these findings in the context of a SARS-CoV-2 disease manifesting while there is an underlying cryptococcal infection.<\/jats:p>","DOI":"10.3390\/cells11030437","type":"journal-article","created":{"date-parts":[[2022,1,27]],"date-time":"2022-01-27T21:59:55Z","timestamp":1643320795000},"page":"437","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Cryptococcal Protease(s) and the Activation of SARS-CoV-2 Spike (S) Protein"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2915-4543","authenticated-orcid":false,"given":"Nozethu","family":"Mjokane","sequence":"first","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maphori","family":"Maliehe","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0485-2273","authenticated-orcid":false,"given":"Olufemi S.","family":"Folorunso","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7886-0524","authenticated-orcid":false,"given":"Adepemi O.","family":"Ogundeji","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0286-8578","authenticated-orcid":false,"given":"Onele M. N.","family":"Gcilitshana","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jacobus","family":"Albertyn","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6928-5663","authenticated-orcid":false,"given":"Carolina H.","family":"Pohl","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0182-1084","authenticated-orcid":false,"given":"Olihile M.","family":"Sebolai","sequence":"additional","affiliation":[{"name":"Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Park West, Bloemfontein 9301, South Africa"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/j.cell.2020.02.058","article-title":"Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein","volume":"180","author":"Walls","year":"2020","journal-title":"Cell"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1361","DOI":"10.1001\/jama.2020.14901","article-title":"Prone Positioning for Acute Respiratory Distress Syndrome (ARDS)","volume":"324","author":"Hadaya","year":"2020","journal-title":"JAMA"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2265","DOI":"10.1001\/jama.2020.8539","article-title":"Is the Prone Position Helpful During Spontaneous Breathing in Patients With COVID-19?","volume":"323","author":"Telias","year":"2020","journal-title":"JAMA"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1093\/clinchem\/hvaa029","article-title":"Molecular diagnosis of a novel coronavirus (2019-nCoV) causing an outbreak of pneumonia","volume":"66","author":"Chu","year":"2020","journal-title":"Clin. 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