Laboratory of Structural Biology Research, NIAMS, National Institutes of Health, Bethesda, MD 20892, USA.
Protein Expression Laboratory, NIAMS, National Institutes of Health, Bethesda, MD 20892, USA.
Structure. 2018 Oct 2;26(10):1314-1326.e4. doi: 10.1016/j.str.2018.06.012. Epub 2018 Aug 9.
Hepatitis B virus (HBV) is the leading cause of liver disease worldwide. While an adequate vaccine is available, current treatment options are limited, not highly effective, and associated with adverse effects, encouraging the development of alternative therapeutics. The HBV core gene encodes two different proteins: core, which forms the viral nucleocapsid, and pre-core, which serves as an immune modulator with multiple points of action. The two proteins mostly have the same sequence, although they differ at their N and C termini and in their dimeric arrangements. Previously, we engineered two human-framework antibody fragments (Fab/scFv) with nano- to picomolar affinities for both proteins. Here, by means of X-ray crystallography, analytical ultracentrifugation, and electron microscopy, we demonstrate that the antibodies have non-overlapping epitopes and effectively block biologically important assemblies of both proteins. These properties, together with the anticipated high tolerability and long half-lives of the antibodies, make them promising therapeutics.
乙型肝炎病毒 (HBV) 是全球范围内导致肝脏疾病的主要原因。虽然有足够的疫苗，但目前的治疗选择有限，效果不佳，且存在不良反应，这促使人们开发替代疗法。HBV 核心基因编码两种不同的蛋白质：核心蛋白，形成病毒核衣壳；前核心蛋白，作为一种具有多种作用点的免疫调节剂。这两种蛋白质的序列基本相同，但在 N 端和 C 端以及二聚体排列上存在差异。此前，我们构建了两种具有纳摩尔至皮摩尔亲和力的人源框架抗体片段（Fab/scFv），可与这两种蛋白质结合。在此，我们通过 X 射线晶体学、分析超速离心和电子显微镜，证明这些抗体具有非重叠的表位，可有效阻断两种蛋白质的生物重要组装。这些特性，加上预期的高耐受性和抗体的长半衰期，使它们成为有前途的治疗药物。
