On the neutron scattering length density of proteins in H2O/D2O
On the neutron scattering length density of proteins in H2O/D2O
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DOI：
10.1016/j.physb.2004.03.227
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发表时间：
2004-07-15
影响因子：
2.8
通讯作者：
Bouwman, W. G.
中科院分区：
文献类型：
--
作者：
Efimova, Y. M.;van Well, A. A.;Bouwman, W. G.
利用中子反射和小角中子散射可以确定吸附在不同界面上的蛋白质层的结构。为了突出界面上吸附的蛋白质层，经常使用通过改变H2O/D2O比来改变对比度的技术。为了确定散射长度密度，需要蛋白质在溶液中的体积和蛋白质的总散射长度。根据氨基酸序列计算体积。在计算散射长度时，应考虑蛋白质不稳定质子的H/D交换。为了监测H/D交换，采用了正电喷雾电离质谱仪。我们将溶菌酶和β-酪蛋白的交换实验结果与理论计算进行了比较。通过对不同水体对比度下的中子反射数据的联立模型拟合，阐明了使用正确的蛋白质散射长度密度的重要性。(C)2004爱思唯尔B.V.保留所有权利。
The structure of the protein layers adsorbed at different interfaces can be determined by using neutron-reflection and small-angle neutron scattering. For highlighting the adsorbed protein layer at the interface, the technique of contrast-variation by changing the H2O/D2O ratio, is often used. For determining the scattering length density, both the protein volume in solution and the total scattering length of the protein is needed. The volume is calculated from the amino-acid sequence. For calculating the scattering length, the H/D exchange of the labile protons of the protein should be taken into account. For monitoring the H/D exchange, Positive Electrospray Ionization Mass Spectroscopy was applied. We compare experimental results for the exchange in lysozyme and beta-casein with theoretical calculations. The importance of using the correct protein scattering-length density is elucidated by simultaneous model fitting to neutron reflection data at different water contrasts. (C) 2004 Elsevier B.V. All rights reserved.