Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule-Hönggerberg, CH-8093, Zürich, Switzerland.
J Biomol NMR. 1996 Mar;7(2):99-106. doi: 10.1007/BF00203820.
Three-dimensional (1)H-TOCSY-relayed ct-[(13)C,(1)H]-HMQC is a novel experiment for aromatic spin system identification in uniformly (13)C-labeled proteins, which is implemented so that it correlates the chemical shift of a given aromatic proton with those of the directly attached carbon and all vicinal protons. The ct-HMQC scheme is used both for overlay of the indirect (1)H and (13)C chemical shift evolution periods and for the generation of (1)H-(1)H antiphase magnetization to accelerate the (1)H-TOCSY magnetization transfer at short mixing times. As an illustration, data recorded for the 18 kDa protein cyclophilin A are presented. Since transverse relaxation of (13)C-(1)H zero-quantum and double-quantum coherences is to first order insensitive to (13)C-(1)H heteronuclear dipolar relaxation, the new experiment should work also for proteins with molecular weights above 20 kDa.
三维 (1)H-TOCSY 相关 ct-[(13)C,(1)H]-HMQC 是一种用于鉴定均匀 (13)C 标记蛋白中芳香自旋系统的新型实验，它将给定芳香质子的化学位移与直接连接的碳和所有相邻质子的化学位移相关联。ct-HMQC 方案既用于间接 (1)H 和 (13)C 化学位移演化期的叠加，也用于生成 (1)H-(1)H 反相磁化，以在短混合时间内加速 (1)H-TOCSY 磁化转移。作为说明，给出了针对 18 kDa 蛋白亲环素 A 记录的数据。由于 (13)C-(1)H 零量子和双量子相干的横向弛豫在一阶上对 (13)C-(1)H 异核偶极弛豫不敏感，因此该新实验也应该适用于分子量大于 20 kDa 的蛋白质。
