Development of NMR measurement and analysis method for protein structural study in 2H2O solution.

我们开发了一个核磁共振脉冲序列，3DHCA(N)CO，用于将蛋白质骨架1H和13C的化学位移与之前残基的13C‘化学位移相关联。当与HCACO、HCAN和HCA(CO)N结合时，HCA(N)CO序列允许使用主干13C‘和酰胺15N化学位移进行顺序分配，而不求助于主干酰胺质子。这一分配策略对13C/15N标记的GB1在2H2O中的溶解进行了验证。在2H2O中测定的GB1结构的质量与在H2O中测定的相似，尽管NOE关联的数量要少得多。因此，这一策略能够在高pH值下确定2H2O或H2O中的蛋白质结构。

We developed an NMR pulse sequence, 3D HCA(N)CO, to correlate the chemical shifts of protein backbone 1H and 13C to those of 13C' in the preceding residue. When combined with HCACO, HCAN and HCA(CO)N, the HCA(N)CO sequence allows the sequential assignment using backbone 13C' and amide 15N chemical shifts without resort to backbone amide protons. This assignment strategy was demonstrated for 13C/15N-labeled GB1 dissolved in 2H2O. The quality of the GB1 structure determined in 2H2O was similar to that determined in H2O in spite of significantly smaller number of NOE correlations. Thus this strategy enables the determination of protein structures in 2H2O or H2O at high pH values.