Veenstra T D, Lee L
Department of Chemistry and Biochemistry, University of Windsor, Ontario, Canada.
Biophys J. 1994 Jul;67(1):331-5. doi: 10.1016/S0006-3495(94)80485-0.
The binding of uridine vanadate to ribonuclease A has been investigated by one- and two-dimensional 1H NMR. The homonuclear Nuclear Overhauser and exchange spectroscopy spectrum of the uridine vanadate/RNase A complex exhibits cross peaks between both the C5H and C6H protons of uridine vanadate and the H epsilon 1 proton of His-12 of ribonuclease A. These cross peaks suggest that the H epsilon 1 proton of His-12 is in the vicinity of the uracil base of uridine vanadate, as observed in the crystallographic structure of the uridine vanadate/RNase A complex. However, no cross peaks are observed between the C5H and C6H protons of uridine vanadate and the H epsilon 1 proton of His-119 of ribonuclease A, although they were predicted based upon the distances calculated from coordinates of the crystallographic structure of the complex. These results suggest that there is a significant difference between the positioning of the His-119 side chain in the solution and in the crystallographic structures.
通过一维和二维¹H NMR研究了钒酸尿苷与核糖核酸酶A的结合。钒酸尿苷/核糖核酸酶A复合物的同核核Overhauser和交换光谱显示，钒酸尿苷的C5H和C6H质子与核糖核酸酶A的His-12的Hε1质子之间存在交叉峰。这些交叉峰表明，His-12的Hε1质子位于钒酸尿苷尿嘧啶碱基附近，这与钒酸尿苷/核糖核酸酶A复合物的晶体结构中观察到的情况一致。然而，尽管根据复合物晶体结构坐标计算的距离预测了钒酸尿苷的C5H和C6H质子与核糖核酸酶A的His-119的Hε1质子之间会出现交叉峰，但实际上并未观察到。这些结果表明，His-119侧链在溶液中的定位与晶体结构中的定位存在显著差异。
