Stoyloff R, Strecker A, Bode L, Franke P, Ludwig H, Hucho F
Institut für Virologie, Freie Universität Berlin, Germany.
Eur J Biochem. 1997 May 15;246(1):252-7. doi: 10.1111/j.1432-1033.1997.t01-2-00252.x.
Borna disease virus (BDV) is representative of the family of Bornaviridae in the order Mononegavirales (negative-stranded, non-segmented, enveloped RNA viruses). It is the causal agent for Borna disease, characterized as an encephalomyelitis (typical form) in a wide variety of domestic animals (from rodents to birds). Recent information shows the involvement of BDV in the pathogenesis of some human psychiatric disorders. The 8.9-kb viral antigenome codes for five major ORF. The third ORF codes for a 16-kDa protein (matrix protein) that is posttranslationally modified, yielding an N-linked glycoprotein. Our data show that the glycosylated matrix protein exists as a stable tetrameric structure detectable either by electrospray ionization or matrix-assisted laser-desorption ionization mass spectrometry. Under native conditions, the tetramer, with a relative molecular mass of 68 kDa, was isolated from a sediment-free brain suspension of a BDV-infected horse. The 68-kDa entity is stable in the presence of ionic and nonionic detergents but dissociates into subunits when heated. We found that the tetrameric matrix protein inhibits in vitro BDV infection in a dose-dependent manner. In contrast to inhibition of BDV infection with hydrophobic carbohydrate derivatives and protein-bound glycoconjugates, the glycosylated matrix protein is a very potent inhibitor of BDV infection, indicating that this protein represents an essential virus-specific membrane component for viral attachment.
博尔纳病病毒（BDV）是单股负链RNA病毒目博尔纳病毒科的代表病毒。它是博尔纳病的病原体，在多种家畜（从啮齿动物到鸟类）中引发脑脊髓炎（典型形式）。最新信息表明BDV与某些人类精神疾病的发病机制有关。8.9kb的病毒反基因组编码五个主要开放阅读框（ORF）。第三个ORF编码一种16kDa的蛋白质（基质蛋白），该蛋白经过翻译后修饰，产生一种N-连接糖蛋白。我们的数据表明，糖基化基质蛋白以稳定的四聚体结构存在，可通过电喷雾电离或基质辅助激光解吸电离质谱检测到。在天然条件下，从感染BDV的马的无沉淀脑悬液中分离出相对分子质量为68kDa的四聚体。68kDa的实体在离子和非离子去污剂存在下稳定，但加热时会解离成亚基。我们发现四聚体基质蛋白以剂量依赖的方式抑制体外BDV感染。与用疏水碳水化合物衍生物和蛋白质结合的糖缀合物抑制BDV感染不同，糖基化基质蛋白是BDV感染的一种非常有效的抑制剂，表明该蛋白代表病毒附着所必需的病毒特异性膜成分。
