Grzesiek S, Bax A
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
J Biomol NMR. 1993 Mar;3(2):185-204. doi: 10.1007/BF00178261.
Experiments and procedures are described that greatly alleviate the sequential assignment process of uniformly 13C/15N-enriched proteins by determining the type of amino acid from experiments that correlate side chain with backbone amide resonances. A recently proposed 3D NMR experiment, CBCA(CO)NH, correlates C alpha and C beta resonances to the backbone amide 1H and 15N resonances of the next residue (Grzesiek, S. and Bax, A. (1992) J. Am. Chem. Soc., 114, 6291-6293). An extension of this experiment is described which correlates the proton H beta and H alpha resonances to the amide 1H and 15N resonances of the next amino acid, and a detailed product operator description is given. A simple 2D-edited constant-time HSQC experiment is described which rapidly identifies H beta and C beta resonances of aromatic or Asn/Asp residues. The extent to which combined knowledge of the C alpha and C beta chemical shift values determines the amino acid type is investigated, and it is demonstrated that the combined C alpha and C beta chemical shifts of three or four adjacent residues usually are sufficient for defining a unique position in the protein sequence.
本文描述了一些实验和方法，这些实验和方法通过从将侧链与主链酰胺共振相关联的实验中确定氨基酸类型，极大地简化了均匀13C/15N标记蛋白质的顺序分配过程。最近提出的一种3D NMR实验，即CBCA(CO)NH，将Cα和Cβ共振与下一个残基的主链酰胺1H和15N共振相关联（Grzesiek, S.和Bax, A. (1992) J. Am. Chem. Soc., 114, 6291 - 6293）。本文描述了该实验的一个扩展，它将质子Hβ和Hα共振与下一个氨基酸的酰胺1H和15N共振相关联，并给出了详细的产物算符描述。本文还描述了一个简单的二维编辑恒时HSQC实验，该实验可快速识别芳香族或Asn/Asp残基的Hβ和Cβ共振。研究了Cα和Cβ化学位移值的综合知识在多大程度上决定氨基酸类型，结果表明，三个或四个相邻残基的Cα和Cβ化学位移组合通常足以确定蛋白质序列中的一个独特位置。
