苹果锈果类病毒的温度梯度凝胶电泳

TEMPERATURE-GRADIENT GEL ELECTROPHORESIS OF APPLE SCAR SKIN VIROID

用温度梯度凝胶电泳技术研究了苹果锈果类病毒(ASSV)的变性行为,并与菊花矮化类病毒(CSV)的变性行为进行了比较。提纯的 ASSV 的温度梯度电泳示出了类病毒特有的从类似于棒状的分子到打开的环状分子的构象转变曲线,与 CSV 及报道的马铃薯纺锤块状类病毒(PSTV)相似。但 ASSV 的构象转变中点温度及转变的协同性均低于 CSV。在8.9mol/LTBE 缓冲液中,ASSV 构象转变的中点温度和半辐值分别为41.5℃和2.4℃,而 CSV 的分别为46.0℃和1.0℃。在 ASSV 的温度梯度凝胶电泳图中,除了有代表单分子构象转变的曲线外,还观察到另一构象转变曲线,作者认为这代表了在提纯过程中由分子间碱基配对形成的双分子复合体的变性曲线。

The Temperature-gradient gel electro-phoresis technique was applied to study thethermodynamic trasition of apple scar skinviroid(ASSV)as well as chrysanthemumstunt viroid(CSV).Purified ASSV showstransition curve which is typical for viroidfrom rod-like to open-circular structure,si-milar to that of CSV and PSTV.The mid-point temperature(Tm value)and co-operati-vity of the transition of ASSV are lower thanthat of CSV.In 0.1×TBE buffer the Tmvalue and the halfwidth of the trasition ofASSV are 41.5℃ and 2.4℃ respectivily,whilethose of CSV are 46.0℃ and 1.0℃.In ad-dition to the transition curve responsible forthe monomolecule of ASSV,another curvewhich may be responsible for the tansition ofbimolecular complex formed during purifica-tion was observed.