{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T05:52:05Z","timestamp":1791525125362,"version":"4.3.4"},"reference-count":57,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T00:00:00Z","timestamp":1791504000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Hepatitis B Virus (HBV) causes a significant global health burden. The HBV core (HBc) protein forms the HBV capsid and has a crucial role in the virus replication cycle. When expressed across different platforms, HBc can self-assemble into HBV-capsid-based virus-like particles (VLPs), with a wide range of applications in both fundamental and pharmaceutical research. Due to their ability to display or crosslink foreign antigens on the surface, HBc VLPs are used as vaccine antigens. However, conventional VLP purification methods face challenges in scalability and achieving high yields. Therefore, investigating the generation and purification process of these VLPs is of high interest.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      HBc VLPs composed of three different forms of HBc protein were expressed in\n                      <jats:italic>E. coli<\/jats:italic>\n                      \u2013 D (full-length, 183 aa), \u0394D\n                      <jats:sub>163<\/jats:sub>\n                      (C-terminal partially truncated, 163 aa), and \u0394D\n                      <jats:sub>149<\/jats:sub>\n                      (C-terminal fully truncated, 149 aa). Polyethyleneimine precipitation (PEI) was performed for excess nucleic acid reduction, followed by two stages of ammonium sulfate precipitation (AS). For a final purification anion-exchange chromatography (AEX) was performed. Purified HBc VPLs were analyzed for purity and stability by SDS-PAGE, native agarose gel electrophoresis, ELISA, Dynamic light scattering, electron microscopy and host cell protein and DNA and endotoxin assays.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The single AEX step method resulted in high purity (&amp;gt;85%) and reduced host-cell residues comparable to those detected in a sample produced under good manufacturing practice (GMP) conditions. The HBc VLP variants yielded 5.2 mg, 25.9 mg, and 27.8 mg purified capsids per liter E. coli culture, respectively. Our data showed that all three VLP forms preserved their correct assembly and exhibited minimal aggregation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>We successfully designed an HBc-VLP purification technique for the purification of different HBV core antigen particles. The purification resulted in highly pure and little aggregated VLP. This purification method is therefore well-positioned to accelerate studies of HBc VLPs.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmicb.2026.1904236","type":"journal-article","created":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T05:34:26Z","timestamp":1791524066000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["A single anion exchange chromatography step enables scalable, high-yield purification of hepatitis B virus capsid virus-like particles"],"prefix":"10.3389","volume":"17","author":[{"given":"A.","family":"Seidler","sequence":"first","affiliation":[{"name":"Institute of Virology, School of Medicine, Technical University of Munich and Helmholtz Munich","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S.","family":"Ambike","sequence":"additional","affiliation":[{"name":"Institute of Virology, School of Medicine, Technical University of Munich and Helmholtz Munich","place":["Munich, Germany"]},{"name":"Program in Emerging Infectious Diseases, Duke-NUS Medical School","place":["Singapore, Singapore"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C.","family":"Peters","sequence":"additional","affiliation":[{"name":"Electron Microscopy Faculty, Chemistry Department, Technical University of Munich","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R.","family":"Bester","sequence":"additional","affiliation":[{"name":"Institute of Virology, School of Medicine, Technical University of Munich and Helmholtz Munich","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Sattler","sequence":"additional","affiliation":[{"name":"Hemholtz Munich, Institute of Structural Biology","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A.","family":"Geerlof","sequence":"additional","affiliation":[{"name":"Hemholtz Munich, Institute of Structural Biology","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"U.","family":"Protzer","sequence":"additional","affiliation":[{"name":"Institute of Virology, School of Medicine, Technical University of Munich and Helmholtz Munich","place":["Munich, Germany"]},{"name":"German Center for Infection Research (DZIF), Munich Partner Site","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,10,9]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"6425","DOI":"10.1021\/acs.biomac.4c00521","article-title":"Label-free tracking of hepatitis B virus Core protein capsid assembly in real-time using protein charge transfer spectra","volume":"25","author":"Alom","year":"2024","journal-title":"Biomacromolecules"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"7868","DOI":"10.1021\/jacs.0c01092","article-title":"Rapidly forming early intermediate structures dictate the pathway of capsid assembly","volume":"142","author":"Asor","year":"2020","journal-title":"J. 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