淋巴囊肿病毒中国株TNFR类似物的原核表达与结构分析

Analysis and Expression of Tumor Necrosis Factor Receptor Homolog from LCDV-C

肿瘤坏死因子受体(TNFR)是细胞因子受体家族中的一员,在大DNA病毒的免疫逃避中起着重要的作用。 淋巴囊肿病毒中国株(LCDV-C)是一种大DNA病毒,属于虹彩病毒科。参照已知虹彩病毒TNFR基因设计引物: P1,5′GGATCCAAAACTATGATTAAAATAAAGA 3′;P2:5′ATTACTCGAGAATGTTAAAAATTAAGCTT 3′。以LCDV-C基因组DNA为模板,PCR扩增得到一个834bp的DNA片段,并对该片段进行测序。构建原核表 达重组质粒后,在大肠杆菌DE3中诱导表达,其产物经SDS-PAGE电泳后,显示为45kDa的融合蛋白带。对测序 结果进行计算机辅助分析的结果显示,LCDV-C TNFR类似物是一个含278个氨基酸的多肽,具有典型的半胱氨 酸富集区功能结构域,与宿主牙鲆TNFRII氨基酸同源性为34％。

Tumor necrosis factor receptor （TNFR） plays an important role in the evasion of immune response by large DNA viruses. TNFR is a homologue of cellular receptors. Lymphocystis disease virus, an iriduvirus, isolated in China （LCDV-C） is a large DNA virus. Primers were designed based on conserved TNFR nucleotide sequences in iridoviruses and used to amplify the homologue in LCDV-C. A DNA fragment of 834 bp was generated and sequenced. The recombinant prokaryotic expression plasmid containing this fragment was constructed and expressed in E. coll. DE3. An expected 45kDa fusion protein was isolated by SDS-PAGE. Computer analysis indicated that LCDV-C TNFR homologue encodes a 278aa putative protein, which contains a typical cysteine-rich domain. It shares 34% identity with flounder TNFRII.