POLYMERIZATION-DEPOLYMERIZATION OF TOBACCO MOSAIC VIRUS PROTEIN .12. FURTHER STUDIES ON ROLE OF WATER
POLYMERIZATION-DEPOLYMERIZATION OF TOBACCO MOSAIC VIRUS PROTEIN .12. FURTHER STUDIES ON ROLE OF WATER
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DOI：
10.1021/bi00835a059
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发表时间：
1969-01-01
期刊：
影响因子：
2.9
通讯作者：
LAUFFER, MA
中科院分区：
文献类型：
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作者：
JAENICKE, R;LAUFFER, MA
Rainer Jaenickef和Max A.Lauffer摘要：烟草病毒蛋白的吸热聚合依赖于蛋白质亚基之间的熵或疏水相互作用，从而在结合过程中产生一定的水分释放。根据以往的pH变化实验，可以用甘油作为高密度的溶剂组分，在石英弹簧天平上通过平衡析出来估算聚合放水量。由于聚合反应的吸热性质，通过改变温度进行聚合时，蛋白质的失水量为0.033±0.00035克/克蛋白质。这一数字相当于约96摩尔/摩尔的烟草花叶病毒蛋白三聚体(分子量52,500)。为了消除温度对春季平衡的影响以及蛋白质部分比体积的非特异性变化所造成的影响，以完整病毒烟草花叶病毒为参照物。用温度计和膨胀计测量的烟草花叶病毒及其外壳蛋白(聚合范围外)的部分比体积与温度的关系是错综复杂的，表现出线性关系。
Rainer Jaenickef and Max A. Lauffer abstract: The endothermic polymerization of tobacco mo-saic virus protein depends upon entropic or “hydrophobic” interactions between the protein subunits leading to a definite water release during the association process. As shown by previous pH change experiments, the amount of water released upon polymerization can be estimated from equilibrium dial-ysis in a quartz spring balance, using glycerol as the solvent component of high density. When, because of the endothermic character of the polymerization reaction, polymerization is brought about by change of temperature, the amount of water lost by the protein is found to be 0.033±0.00035 g/g of protein. This figure corresponds to about 96 moles/mole of tobacco mosaic virusprotein trimer (molecular weight 52,500). To eliminate temperature effects on the spring balance as well as effects caused by unspecific changes of the partial specific volume of the protein, intact virus, tobaccomosaic virus, was used as reference. The temperature dependences of the partial specific volumes of both tobacco mosaic virus and its coat protein (outside the polymerization range) as measured with pycnometers and dilatometers are indentical, showing a linear