COMPRESSIBILITY OF GLOBULAR-PROTEINS IN WATER AT 25-DEGREES-C
COMPRESSIBILITY OF GLOBULAR-PROTEINS IN WATER AT 25-DEGREES-C
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DOI：
10.1021/j100484a006
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发表时间：
1979-01-01
影响因子：
--
通讯作者：
NOGUCHI, H
中科院分区：
文献类型：
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作者：
GEKKO, K;NOGUCHI, H
在25 ℃下，用“环绕脉冲法”测量声速，测定了14种球状蛋白质在水中的绝热压缩系数ft。所有研究的蛋白质均显示出正压缩性，表明蛋白质具有较大的内部压缩性。为了讨论从蛋白质的空隙和水化的观点获得的数据，检查FT和一些分子参数之间的相关性，如蛋白质的部分比体积，疏水性和极性。此外，尝试分别估计孔隙和水合作用对蛋白质可压缩性的贡献。这些结果表明，由压力引起的空隙的大的负压缩补偿了由于蛋白质的水合引起的正压缩，导致ft的小的正值。这样一个大的可压缩性的空隙支持的命题，即蛋白质的可压缩性的增加，变性是由于变性蛋白质的非极性基团的高局部浓度。从所获得的绝热压缩性数据，六种蛋白质的等温压缩性估计通过使用的热膨胀系数和热容数据的蛋白质。
The adiabatic compressibility, ft, of 14 globular proteins in water was determined at 25 C by sound velocity measurements with a “sing around pulse method”. All proteins studied showed positive compressibilities, suggesting a large internal compressibility for the proteins. To discuss the data obtained from the viewpoint of void and hydration of the proteins, a correlation was examined between ft and some molecular parameters such as the partial specific volume, hydrophobicity, and polarity of the proteins. Further, an attempt was made to estimate separately the contributions of void and hydration to the compressibility of proteins. These results revealed that a large negative compression of the void by pressure compensates a positive compression due to the hydration of the protein, resulting in a small positive value for ft. Such a large compressibility of the void supports the proposition that the increase in compressibility of the protein by denaturation is due to the high local concentration of nonpolar groups of denatured protein. From the obtained adiabatic compressibility data, the isothermal compressibility of six proteins was estimated by using the thermal expansion coefficient and the heat capacity data for the proteins.