1H, 13C and 15N NMR assignments and secondary structure of the paramagnetic form of rat cytochrome b5.
1H, 13C and 15N NMR assignments and secondary structure of the paramagnetic form of rat cytochrome b5.
复制标题
大鼠细胞色素 b5 顺磁性形式的 1H、13C 和 15N NMR 归属和二级结构。
DOI：
10.1007/bf00211163
复制
发表时间：
1996
影响因子：
2.7
通讯作者：
Guiles,RD
中科院分区：
文献类型：
--
作者：
Sarma,S;DiGate,RJ;Banville,DL;Guiles,RD
现代多维双和三重共振NMR方法已被应用到分配的骨干和侧链13 C共振的顺磁性形式的大鼠肝微粒体细胞色素b5的平衡构象。骨架13 C共振的归属用于确认先前的1H和15 N共振归属[Guiles，R.D.等人（1993）Biochemistry，32，8329-8340]。根据短、中程NOE和骨架13 C化学位移，测定了大鼠细胞色素b 5溶液的二级结构。这两种平衡形式的骨架13 C共振的惊人相似性强烈表明，这两种异构体的二级结构几乎相同。发现主链和侧链原子的~（13）C化学位移对顺磁效应相对不敏感。在各向异性顺磁系统，可以观察到大的伪接触位移，这种方法的可靠性进行评估，通过计算这种变化的幅度。
Modern multidimensional double- and triple-resonance NMR methods have been applied to assign the backbone and side-chain13C resonances for both equilibrium conformers of the paramagnetic form of rat liver microsomal cytochromeb5. The assignment of backbone13C resonances was used to confirm previous1H and15N resonance assignments [Guiles, R.D. et al. (1993)Biochemistry,32, 8329–8340]. On the basis of short- and medium-range NOEs and backbone13C chemical shifts, the solution secondary structure of rat cytochromeb5has been determined. The striking similarity of backbone13C resonances for both equilibrium forms strongly suggests that the secondary structures of the two isomers are virtually identical. It has been found that the13C chemical shifts of both backbone and side-chain atoms are relatively insensitive to paramagnetic effects. The reliability of such methods in anisotropic paramagnetic systems, where large pseudocontact shifts can be observed, is evaluated through calculations of the magnitude of such shifts.