{"id":4974,"date":"2021-07-21T09:48:21","date_gmt":"2021-07-21T00:48:21","guid":{"rendered":"https:\/\/www.emukk.com\/WP\/?p=4963"},"modified":"2021-07-21T09:56:36","modified_gmt":"2021-07-21T00:56:36","slug":"the-most-potent-neutralizing-antibody-developed-with-antibody-phage-display-from-covid-19-convalescent-patients","status":"publish","type":"post","link":"https:\/\/www.emukk.com\/WP\/en\/the-most-potent-neutralizing-antibody-developed-with-antibody-phage-display-from-covid-19-convalescent-patients\/","title":{"rendered":"The most potent neutralizing antibody developed with antibody phage display from COVID-19 convalescent patients\u00a0"},"content":{"rendered":"

A group from Technische Universit\u00e4t Braunschweig, Institut f\u00fcr Biochemie, Biotechnologie und Bioinformatik, Abteilung Biotechnologie, Germany, etc. has reported on the most potent neutralizing antibody developed with antibody phage display from COVID-19 convalescent patients.
\nhttps:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC8260561\/<\/a><\/p>\n

Antibody phage display is now widely used as in vitro technology to select human antibody fragments for the development of therapeutic antibodies against target disease.
\nIn this author’s work, immune phage display libraries from six COVID-19 convalescent patients were constructed and RBD-binding antibodies have been selected, to develop SARS-CoV-2-inhibiting and -neutralizing antibodies. <\/p>\n

30 antibodies were screened in a cytopathic effect (CPE)-based neutralization screening assay to select antibodies for further characterization as IgG. This assay was performed with 250 plaque-forming units (pfu)\/well SARS-CoV-2 and 1 \u03bcg\/mL (\u223c10 nM) scFv-Fc. CPE is characterized by rounding and detachment clearly visible in phase contrast microscopy upon SARS-CoV-2 infection within 4 days, while uninfected cells maintained an undisturbed confluent monolayer. The best neutralizing 19 scFv-Fc were re-cloned and produced as human IgG in 50-mL culture scales. Half-maximal effective concentration (EC50) values of binding to RBD, S1, or S1-S2 were determined. Antibodies named STE90-C11, STE90-B2-D12, STE94-F6, and STE94-H2 showed EC50 values ranging between 0.2 and 0.5 nM on all of the antigens tested. As a result, STE90-C11 antibody was selected as the most potent one.<\/p>\n

Excitingly, STE90-C11 was tolerant to most known RBD mutants as shown below, especially those of the mutants B.1.429\/B.1.427, B.1.526, B1.258\u0394, B.1.535, B.1.617, and B.1.1.33, which are currently emerging.<\/p>\n

\"\"<\/a><\/p>\n

To get further insight into the neutralizing mechanism of STE90-C11, a complex of STE90-C11 Fab and SARS-CoV-2 RBD was prepared and subjected to crystallization screening. X-ray diffraction images collected from the resulting crystals yielded a dataset to an overall resolution limit of 2.0 \u00c5. After solving the structure by molecular replacement, a model was built into the electron density. Roughly 60% of this binding area can be contributed to the VH segment, forming up to 10 hydrogen bonds at the same time. The remaining 40% are provided by the VL segment contributing 8 additional hydrogen bonds to stabilize the interaction. The superposition of the RBDs of the STE90-C11:SARS-CoV-2 RBD complex with a ACE2:SARS-CoV-2 RBD complex revealed that the neutralization mechanism of STE90-C11 is based on directly competing for the ACE2 binding side, as the interaction interfaces on the RBD of both molecules almost completely overlap.\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

A group from Technische Universit\u00e4t Braunschweig, Institut f\u00fcr Biochemie, Biotechnologie und Bioinformatik, Ab<\/p><\/div>\n

\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[70,7],"tags":[],"class_list":["post-4974","post","type-post","status-publish","format-standard","hentry","category-nature-en","category-technology-en"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t