Department of Chemistry and Biochemistry, University of Colorado, Campus Box 215, Boulder, CO, 80309-0215, U.S.A..
J Biomol NMR. 1999 Jun;14(2):175-9. doi: 10.1023/A:1008304332574.
Large residual (15)N-(1)H dipolar couplings have been measured in a Src homology II domain aligned at Pf1 bacteriophage concentrations an order of magnitude lower than used for induction of a similar degree of alignment of nucleic acids and highly acidic proteins. An increase in (1) H and (15)N protein linewidths and a decrease in T(2) and T(1)ρ relaxation time constants implicates a binding interaction between the protein and phage as the mechanism of alignment. However, the associated increased linewidth does not preclude the accurate measurement of large dipolar couplings in the aligned protein. A good correlation is observed between measured dipolar couplings and predicted values based on the high resolution NMR structure of the SH2 domain. The observation of binding-induced protein alignment promises to broaden the scope of alignment techniques by extending their applicability to proteins that are able to interact weakly with the alignment medium.
在 Pf1 噬菌体浓度下，Src 同源结构域 2 排列整齐，残留的（15）N-（1）H 偶极耦合被测量到，其浓度比诱导核酸和高度酸性蛋白质排列整齐的浓度低一个数量级。（1）H 和（15）N 蛋白质线宽增加，T（2）和 T（1）ρ 弛豫时间常数降低，表明蛋白质与噬菌体之间的结合相互作用是排列整齐的机制。然而，相关的线宽增加并不排除在排列整齐的蛋白质中准确测量大偶极耦合的可能性。观察到的偶极耦合与基于 SH2 结构域的高分辨率 NMR 结构的预测值之间存在良好的相关性。结合诱导的蛋白质排列的观察有望通过将其应用扩展到能够与排列介质弱相互作用的蛋白质来拓宽排列技术的范围。
