西藏新分离环状病毒毒粒沉降系数及分子量的研究

Studies on sedimentation coefficient and molecular weight of the orbivirus (Ti3010) isolated from Tibet, China

目的：用分析超离心测定病毒毒粒沉降系数及分子量的方法，对从西藏地区新分离的环状病毒Ｔｉ３０１０ 株进行分类鉴定。方法：从病毒感染的ＢＨＫ１３ 细胞悬液中，用ＰＥＧ６０００ 沉淀病毒，ＣＳＣｌ密度梯度离心纯化并测定病毒浮力密度，用分析超速离心机测定病毒毒粒沉降系数（Ｓ）和分子量（Ｍｒ）。结果：病毒在ＣｓＣｌ等密度沉降中呈现两条相分隔的区带，上部区带（即峰２）为密度ρ２＝１．２８８ ｇ／ｍ ｌ不含核酸的空壳病毒粒子，下部区带（即峰３）为密度ρ３＝ １．４１４ ｇ／ｍ ｌ无外壳的核芯（ｃｏｒｅ）和完整毒粒；分析超离心测定峰２、峰３ 粒子的表观沉降系数，Ｓ２＝ ６０６，Ｓ３＝ ４２１；Ｓｖｅｄｂｅｒｇ 方程计算出这两种病毒粒子的Ｚ均分子量分别为Ｍｒ２＝ １２５×１０６，Ｍｒ３＝ ５３×１０６。结论：用分析超离心测定沉降系数的精确度高，所得分子量为绝对分子量值；结合该病毒的基因组ＲＮＡ 分析，表明新分离病毒为一种具有独有特征的环状病毒。

Objective: To identify the newly isolated orbivirus by the method for determination of the sedimentation coefficient and molecular weight of virions using analytical ultracentrifugation. Methods: The virions were purified by cesium chloride density gradient centrifugation. The sedimentation coefficient and molecular weight of the virions were determined by analytical ultracentrifugation. Results: Two discrete bands were generally seen in cesium chloride gradients. The upper band (peak 2) contained mostly empty virions, and the lower band (peak 3) contained core or intact virions. Their sedimentation coefficient were determined by analytical ultracentrifugation to be 606 s and 421 s, respectively. The values of molecular weight for peak 2 and peak 3 calculated by Svedberg equation were 125×10 6 and 53×10 6. Conclusion: The Ti3010 orbivirus may be a new member of the genus Orbivirus of Reoviridae.