6vjt
From Proteopedia
Co-crystals of broadly neutralizing antibody with the linear epitope from Hepatitis B surface antigen
Structural highlights
FunctionA0A5A4RHH5_HBV The large envelope protein exists in two topological conformations, one which is termed 'external' or Le-HBsAg and the other 'internal' or Li-HBsAg. In its external conformation the protein attaches the virus to cell receptors and thereby initiating infection. This interaction determines the species specificity and liver tropism. This attachment induces virion internalization predominantly through caveolin-mediated endocytosis. The large envelope protein also assures fusion between virion membrane and endosomal membrane. In its internal conformation the protein plays a role in virion morphogenesis and mediates the contact with the nucleocapsid like a matrix protein.[HAMAP-Rule:MF_04075] The middle envelope protein plays an important role in the budding of the virion. It is involved in the induction of budding in a nucleocapsid independent way. In this process the majority of envelope proteins bud to form subviral lipoprotein particles of 22 nm of diameter that do not contain a nucleocapsid.[HAMAP-Rule:MF_04075] Publication Abstract from PubMedAlthough there is no effective cure for chronic hepatitis B virus (HBV) infection, antibodies are protective and correlate with recovery from infection. To examine the human antibody response to HBV, we screened 124 vaccinated and 20 infected, spontaneously recovered individuals. The selected individuals produced shared clones of broadly neutralizing antibodies (bNAbs) that targeted 3 non-overlapping epitopes on the HBV S antigen (HBsAg). Single bNAbs protected humanized mice against infection but selected for resistance mutations in mice with prior established infection. In contrast, infection was controlled by a combination of bNAbs targeting non-overlapping epitopes with complementary sensitivity to mutations that commonly emerge during human infection. The co-crystal structure of one of the bNAbs with an HBsAg peptide epitope revealed a stabilized hairpin loop. This structure, which contains residues frequently mutated in clinical immune escape variants, provides a molecular explanation for why immunotherapy for HBV infection may require combinations of complementary bNAbs. A Combination of Human Broadly Neutralizing Antibodies against Hepatitis B Virus HBsAg with Distinct Epitopes Suppresses Escape Mutations.,Wang Q, Michailidis E, Yu Y, Wang Z, Hurley AM, Oren DA, Mayer CT, Gazumyan A, Liu Z, Zhou Y, Schoofs T, Yao KH, Nieke JP, Wu J, Jiang Q, Zou C, Kabbani M, Quirk C, Oliveira T, Chhosphel K, Zhang Q, Schneider WM, Jahan C, Ying T, Horowitz J, Caskey M, Jankovic M, Robbiani DF, Wen Y, de Jong YP, Rice CM, Nussenzweig MC Cell Host Microbe. 2020 Aug 12;28(2):335-349.e6. doi: 10.1016/j.chom.2020.05.010., Epub 2020 Jun 5. PMID:32504577[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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