Svergun D I, Richard S, Koch M H, Sayers Z, Kuprin S, Zaccai G
European Molecular Biology Laboratory, Hamburg Outstation, Notkestrasse 85, D-22603 Hamburg, Germany.
Proc Natl Acad Sci U S A. 1998 Mar 3;95(5):2267-72. doi: 10.1073/pnas.95.5.2267.
The structure of the protein-solvent interface is the subject of controversy in theoretical studies and requires direct experimental characterization. Three proteins with known atomic resolution crystal structure (lysozyme, Escherichia coli thioredoxin reductase, and protein R1 of E. coli ribonucleotide reductase) were investigated in parallel by x-ray and neutron scattering in H2O and D2O solutions. The analysis of the protein-solvent interface is based on the significantly different contrasts for the protein and for the hydration shell. The results point to the existence of a first hydration shell with an average density approximately 10% larger than that of the bulk solvent in the conditions studied. Comparisons with the results of other studies suggest that this may be a general property of aqueous interfaces.
蛋白质-溶剂界面的结构在理论研究中存在争议，需要直接的实验表征。通过在H2O和D2O溶液中进行X射线和中子散射，对三种具有已知原子分辨率晶体结构的蛋白质（溶菌酶、大肠杆菌硫氧还蛋白还原酶和大肠杆菌核糖核苷酸还原酶的R1蛋白）进行了平行研究。对蛋白质-溶剂界面的分析基于蛋白质和水合壳层显著不同的对比度。结果表明，在所研究的条件下，存在一个第一水合壳层，其平均密度比本体溶剂大约10%。与其他研究结果的比较表明，这可能是水相界面的一个普遍特性。
