Uy A, Bruss V, Gerlich W H, Köchel H G, Thomssen R
Virology. 1986 Nov;155(1):89-96. doi: 10.1016/0042-6822(86)90170-4.
Hepatitis B virus (HBV) DNA contains a precore (pre-c) sequence of 29 codons with unknown function upstream of its gene for the major core protein. Its significance was studied by expression of core proteins with and without pre-c in Escherichia coli. Core protein without pre-c, P22c, assembled spontaneously to core particles and formed core antigen. It had the same size and antigenicity as core particles from infected liver. Core protein with pre-c, P25e, instead formed membrane-associated e antigen (HBeAg). The data suggest that pre-c functions as a signal peptide for the attachment of core protein P25e to cellular membranes. This hypothesis can explain the not yet understood relation between viremia and HbeAg and the protective role of anti-HBe antibody.
乙型肝炎病毒（HBV）DNA在其主要核心蛋白基因上游含有一段29个密码子的前核心（pre-c）序列，其功能尚不清楚。通过在大肠杆菌中表达有或无前核心的核心蛋白来研究其意义。无前核心的核心蛋白P22c自发组装成核心颗粒并形成核心抗原。它与感染肝脏中的核心颗粒大小和抗原性相同。有前核心的核心蛋白P25e则形成与膜相关的e抗原（HBeAg）。数据表明，前核心作为一种信号肽，用于将核心蛋白P25e附着于细胞膜。这一假说可以解释尚未明确的病毒血症与HBeAg之间的关系以及抗-HBe抗体的保护作用。
