Meng Kaiwen, Zhang Yueping, Liu Qi, Huyan Yangnan, Zhu Wenzhuang, Xiang Ye, Meng Geng
College of Veterinary Medicine, China Agricultural University, Beijing, China.
School of Medicine, Tsinghua University, Beijing, China.
Front Microbiol. 2022 Jun 14;13:802098. doi: 10.3389/fmicb.2022.802098. eCollection 2022.
In an effort to control the outbreak of the African Swine Fever Virus (ASFV), there is an urgent need to develop an effective method to prevent the pandemic, including vaccines and diagnostic methods. The major capsid protein of ASFV p72 (B646L), which forms a trimer with each monomer adopting a double jelly roll fold, is the main component of the virus particle and major antigen of ASFV. Thus, the p72 protein may be considered an antigen candidate for vaccine and diagnostic development. However, the development of ASFV p72 trimer for the industry application, including veterinary usage, faces unavoidable challenges: firstly, the low cost of the antigen production is required in vaccine and diagnostic application; and, secondly, whether produced antigen folds in its native conformation. Here, based on the information provided by the atomic structure of p72, we have successfully performed rational mutagenesis on p72 trimers and expressed it in with high yields. The cryo-EM structure of recombinant expressed p72 trimer is determined at 4.18 Å in resolution. The correlation coefficient between this structure and the ASFV virus structure is 0.77, suggesting a highly similar fold of this trimer with the native protein on the virus particle.
为了控制非洲猪瘟病毒（ASFV）的爆发，迫切需要开发一种有效的预防大流行的方法，包括疫苗和诊断方法。ASFV的主要衣壳蛋白p72（B646L），每个单体形成三聚体并采用双果冻卷折叠，是病毒颗粒的主要成分和ASFV的主要抗原。因此，p72蛋白可被视为疫苗和诊断开发的抗原候选物。然而，用于包括兽医用途在内的工业应用的ASFV p72三聚体的开发面临不可避免的挑战：首先，疫苗和诊断应用需要低成本的抗原生产；其次，生产的抗原是否以其天然构象折叠。在此，基于p72原子结构提供的信息，我们成功地对p72三聚体进行了合理诱变，并以高产率在其中表达。重组表达的p72三聚体的冷冻电镜结构在4.18 Å分辨率下确定。该结构与ASFV病毒结构之间的相关系数为0.77，表明该三聚体与病毒颗粒上的天然蛋白具有高度相似的折叠。
