title: Crystallographic Identification of Lipid as an Integral Component of the Epitope of HIV Broadly Neutralizing Antibody 4E10.
abstract: Numerous studies of the anti-HIV-1 envelope glycoprotein 41 (gp41) broadly neutralizing antibody 4E10 suggest that 4E10 also interacts with membrane lipids, but the antibody regions contacting lipids and its orientation with respect to the viral membrane are unknown. Vaccine immunogens capable of re-eliciting these membrane proximal external region (MPER)-like antibodies may require a lipid component to be successful. We performed a systematic crystallographic study of lipid binding to 4E10 to identify lipids bound by the antibody and the lipid-interacting regions. We identified phosphatidic acid, phosphatidylglycerol, and glycerol phosphate as specific ligands for 4E10 in the crystal structures. 4E10 used its CDRH1 loop to bind the lipid head groups, while its CDRH3 interacted with the hydrophobic lipid tails. Identification of the lipid binding sites on 4E10 may aid design of immunogens for vaccines that include a lipid component in addition to the MPER on gp41 for generation of broadly neutralizing antibodies.
authors.affiliation: Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Adriana
authors.initials: A
authors.lastname: Irimia
authors.affiliation: Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Anita
authors.initials: A
authors.lastname: Sarkar
authors.affiliation: Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Robyn L
authors.initials: RL
authors.lastname: Stanfield
authors.affiliation: Department of Integrative Structural and Computational Biology, International AIDS Vaccine Initiative Neutralizing Antibody Center, Collaboration for AIDS Vaccine Discovery (CAVD), and Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery (CHAVI-ID), The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: wilson@scripps.edu.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Wilson
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D057134:Antibodies, Neutralizing / Q000276:immunology*; D001666:Binding Sites, Antibody / Q000276:immunology*; D000080908:Broadly Neutralizing Antibodies; D002460:Cell Line; D018360:Crystallography, X-Ray; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry / Q000276:immunology*; D015483:HIV Antibodies / Q000276:immunology*; D006801:Humans; D008563:Membrane Lipids / Q000276:immunology*; D011485:Protein Binding / Q000276:immunology; D011487:Protein Conformation
chemical_list: C558559:4E10 monoclonal antibody; D000911:Antibodies, Monoclonal; D057134:Antibodies, Neutralizing; D000080908:Broadly Neutralizing Antibodies; D018985:Epitopes, B-Lymphocyte; D015483:HIV Antibodies; D008563:Membrane Lipids