病毒衣壳与RNA溶液在极低剪切应力下的准弹性行为。
Quasi-elastic behavior of solutions of viral capsid and RNA at very low shearing stresses.
作者信息
Hodgins M G, Hodgins O C, Kupke D W, Beams J W
出版信息
Proc Natl Acad Sci U S A. 1975 Sep;72(9):3501-4. doi: 10.1073/pnas.72.9.3501.
By the application of shearing stresses on the order of 10(-3) dyne cm-2 (10(-2) muN cm-2), via the magnetic viscodensimeter, extremely high relative viscosities (greater than 500) were observed when turnip yellow mosaic virus was degraded in alkali into its capsid and RNA. The solutions, however, possessed a watery consistency at this stage and exhibited a quasi-elastic character by rotor-recoil experiments. The development of this curious behavior was concentration and temperature dependent; it was not seen less than 0.5% nor at 8 degrees, and appeared sooner at 30 degrees than at 20 degrees. The time of appearance was delayed as the pH was lowered; however, the effect was still observed when the pH was as low as 9. Whereas reversibility was demonstrated when the shearing stresses exceeded the elastic resistance [0.17 dyne cm-2 (1.7 muN CM-2)], thorough mixing usually resulted in a normal behavior of the solutions thereafter. Values for the modulus of rigidity at 20 degrees for about 1% virus concentration was less than 2 X 10(-2) dyne cm-2 rad-1 (0.2 muN cm-2 rad-1), which, while extremely small, was reproducible. A porous structure, possibly involving a capsid and RNA complex, is envisioned.
通过使用磁粘滞计施加约10⁻³达因·厘米⁻²（10⁻²微牛顿·厘米⁻²）的剪切应力，当芜菁黄花叶病毒在碱性条件下分解为其衣壳和RNA时，观察到了极高的相对粘度（大于500）。然而，此时溶液具有似水的稠度，并且通过转子反冲实验表现出准弹性特征。这种奇特行为的发展取决于浓度和温度；在浓度低于0.5%时或在8℃时未观察到，在30℃时比在20℃时出现得更早。出现的时间随着pH值降低而延迟；然而，当pH值低至9时仍能观察到这种效应。当剪切应力超过弹性阻力[0.17达因·厘米⁻²（1.7微牛顿·厘米⁻²）]时证明了可逆性，此后充分混合通常会使溶液表现出正常行为。在20℃时，约1%病毒浓度下的刚性模量值小于2×10⁻²达因·厘米⁻²·弧度⁻¹（0.2微牛顿·厘米⁻²·弧度⁻¹），尽管极小，但却是可重复的。设想存在一种可能涉及衣壳和RNA复合物的多孔结构。
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