Yoshioki Shuzo
Yatsushiro National College of Technology, Japan.
J Comput Chem. 2002 Feb;23(3):402-13. doi: 10.1002/jcc.1170.
Internal and rigid-body motions of bovine pancreatic trypsin inhibitor (BPTI) and of water molecules surrounding the BPTI are studied in a vicinity of an energy minimum using a normal mode analysis proposed as the independent molecule model. Water's rigid-body motion is predominant in comparison to its internal motions. We have derived information about the relationship between the magnitude of a thermal ellipsoid of an H-bonding atom and the anisotropy of its ellipsoid, and the relationship between the magnitude of the ellipsoid and the H-bond strength. We see a relationship between vibrational frequencies (assuming rigid-body motion of the water molecules) and the H-bond strength of the water taking part in this H-bonding. Analyzing the H-bond strength, we found that a hydrogen in water is likely to H-bond to oxygen in the protein, whereas an oxygen in water has a less strong preference to H-bond to the protein. For water molecules acting as the hydrogen acceptor, strong H-bonding has longer lifetimes than weak H-bonding.
使用提出的独立分子模型，通过正常模式分析，研究了牛胰蛋白酶抑制剂（BPTI）的内部和刚体运动以及围绕BPTI的水分子的运动。在能量最小值附近，水的刚体运动与其内部运动相比占主导地位。我们已经得出了有关氢键原子的热椭球大小与其椭球各向异性之间的关系，以及椭球大小与氢键强度之间的关系。我们看到了（假设水分子的刚体运动）振动频率与参与该氢键作用的水的氢键强度之间的关系。通过分析氢键强度，我们发现水中的氢很可能与蛋白质中的氧形成氢键，而水中的氧与蛋白质形成氢键的偏好性较弱。对于充当氢受体的水分子，强氢键的寿命比弱氢键更长。
