THERMAL INACTIVATION OF BACTERIOPHAGE PHIX174 AND 2 OF ITS MUTANTS
THERMAL INACTIVATION OF BACTERIOPHAGE PHIX174 AND 2 OF ITS MUTANTS
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DOI：
10.1016/0042-6822(68)90160-8
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发表时间：
1968-01-01
期刊：
影响因子：
3.7
通讯作者：
ABKOUDE, ERB
中科院分区：
文献类型：
--
作者：
BLEICHRODT, JF;BLOK, J;ABKOUDE, ERB
研究了具有不同吸附性能的噬菌体∅X174两种形式（∅∗和∅）在不同pH、离子强度、温度条件下的热失活。提出了两种形式相似的反应机理。在高温下，失活主要是由于蛋白质的破坏，并取决于吸附位点的结构。在较低的温度下，DNA破坏的贡献更高。除了热敏性不同外，这两种形式的失活率对pH和离子强度的依赖也不同。应用绝对反应速率理论，利用斯登关于蛋白质变性过程中断裂键的焓和活化熵的估计，表明∅∗和∅之间的结构差别可能仅由一个弱非共价键决定。宿主突变体∅X174h1h2和耐热突变体∅x174的阿伦尼乌斯曲线与野生型相似。比较这三种噬菌体的阿伦尼乌斯曲线和它们从∅∗转变为∅形式的速度表明，主要参与这种转变的键并不位于紧邻吸附位点的位置。
The thermal inactivation of the two forms (∅∗ and ∅) of bacteriophage ∅X174 with different adsorption properties was investigated under various conditions of pH, ionic strength, and temperature. A reaction mechanism is proposed that is similar for both forms. At high temperatures inactivation occurs mainly as a result of protein destruction and is dependent on the structure of the adsorption site(s). At lower temperatures the contribution of DNA destruction is higher. In addition to a difference in heat sensitivity, the two forms show a different dependence of their inactivation rate on pH and ionic strength.Application of the theory of absolute reaction rates, using the estimates of Stearn concerning enthalpy and entropy of activation for bonds broken during denaturation of proteins, suggests that the structural difference between ∅∗ and ∅ may be determined by only one weak noncovalent bond.The Arrhenius curves of the host-range mutant ∅X174h1h2 and of the thermoresistant mutant ∅X174stare similar to that of the wild type. Comparison of the Arrhenius curves of these three phages and of their rate of transition from the ∅∗ into the ∅ form suggests that the bonds primarily involved in this transition are not located in the immediate vicinity of the adsorption site(s).