Comparison of reduced and oxidized yeast iso-1-cytochrome c using proton paramagnetic shifts.
Comparison of reduced and oxidized yeast iso-1-cytochrome c using proton paramagnetic shifts.
复制标题
使用质子顺磁位移比较还原和氧化的酵母 iso-1-细胞色素 c。
作者：
Y. Gao;J. Boyd;G. Pielak;R. J. Williams
酵母 iso-1-细胞色素 c 质子的偶极顺磁位移已通过使用优化的 g 张量和酵母 iso-1-细胞色素 c 还原形式的 X 射线晶体坐标计算 [Louie, G. V., & Brayer, G. D. (1990) J. Mol.生物。 214、527-555]。将计算值与从超过 450 个非等价质子确定的观察到的顺磁位移进行比较，这些质子已指定为两种氧化态 [Gao, Y., Boyd, J., Williams, R. J. P., & Pielak, G. J. (1990) Biochemistry 29, 6994-7003]。除少数例外外，计算数据与实验数据之间具有良好的一致性。这表明，总体而言，溶液中还原态和氧化态的溶液结构必须与晶体中的情况非常相似。溶液中分子的观测位移值和计算位移值之间的差异最容易通过血红素的轻微移动以及由于一些残基的小幅重排和一些氢键的一些相当大的变化而引起的抗磁位移的某些变化来解释。还已知晶体中两种氧化态的结构之间存在微小差异，但氢键变化并不那么容易观察到。核磁共振数据的结构变化与晶体学推导的结构变化相当一致，但显然可以获得有关氢键变化的附加信息。
Dipolar paramagnetic shifts for protons of yeast iso-1-cytochrome c have been calculated by using an optimized g-tensor and the X-ray crystallographic coordinates of the reduced form of yeast iso-1-cytochrome c [Louie, G. V., & Brayer, G. D. (1990) J. Mol. Biol. 214, 527-555]. The calculated values are compared with the observed paramagnetic shift determined from over 450 nonequivalent protons that have been assigned in both oxidation states [Gao, Y., Boyd, J., Williams, R. J. P., & Pielak, G. J. (1990) Biochemistry 29, 6994-7003]. There is good agreement between the calculated and the experimental data with a few exceptions. This indicates that, overall, the solution structures must be very similar in both the reduced and oxidized states in solution as is the case in crystals. The differences between observed and calculated shift values for the molecule in solution are most readily explained by slight movement of the heme and certain changes in diamagnetic shift due to small rearrangements of a few residues and some considerable changes in a few hydrogen bonds. It is also known that small differences exist between the structures of the two oxidation states in crystals but the hydrogen-bond changes are not so easily observed there. Structural changes from nuclear magnetic resonance data are in reasonable agreement with those deduced from crystallography, but additional information is clearly available concerning changes in hydrogen bonding.
原核和真核细胞色素的 NMR 比较 c．
影响因子：
2.9
作者：
Chau,MH;Cai,ML;Timkovich,R
通讯作者：
Timkovich,R