Hulst M M, Himes G, Newbigin E, Moormann R J
Virology Department, Central Veterinary Institute, Lelystad, The Netherlands.
Virology. 1994 May 1;200(2):558-65. doi: 10.1006/viro.1994.1218.
Two regions of amino acids homologous to the ribonuclease catalysis domain of the fungal RNases T2 of Aspergillus oryzae and Rh of Rhizopus niveus and the plant S-glycoproteins of Nicotiana alata are perfectly conserved in the amino acid sequence of the envelope glycoprotein E2 of classical swine fever virus (CSFV). To analyze the functional significance of these conserved sequences, the gene encoding E2 was inserted into the p10 locus of baculovirus and expressed in insect cells. Recombinant virus BacCE2 generated a protein which was similar in size (42 to 46 kDa) to wild-type E2 synthesized in swine kidney cells infected with CSFV. Recombinant E2 was purified by immunoaffinity chromatography from the lysate of cells infected with BacCE2 and assayed for RNase activity. RNase activity coeluted with the E2 fraction, indicating that ribonuclease activity is an inherent property of E2. The ribonuclease-specific activity of the protein fraction containing pure E2 was comparable to that of the N. alata S-glycoproteins.
与米曲霉的真菌核糖核酸酶T2、雪白根霉的Rh以及烟草的植物S-糖蛋白的核糖核酸酶催化结构域同源的两个氨基酸区域，在经典猪瘟病毒（CSFV）包膜糖蛋白E2的氨基酸序列中完全保守。为了分析这些保守序列的功能意义，将编码E2的基因插入杆状病毒的p10位点并在昆虫细胞中表达。重组病毒BacCE2产生了一种大小（42至46 kDa）与感染CSFV的猪肾细胞中合成的野生型E2相似的蛋白质。通过免疫亲和层析从感染BacCE2的细胞裂解物中纯化重组E2，并测定其核糖核酸酶活性。核糖核酸酶活性与E2组分共洗脱，表明核糖核酸酶活性是E2的固有特性。含有纯E2的蛋白质组分的核糖核酸酶比活性与烟草S-糖蛋白相当。
