Fujii H, Finnegan M G, Miki T, Crouse B R, Kakinuma K, Johnson M K
Department of Inflammation Research, Tokyo Metropolitan Institute of Medical Science, Japan.
FEBS Lett. 1995 Dec 27;377(3):345-8. doi: 10.1016/0014-5793(95)01372-5.
The combination of electron paramagnetic resonance (EPR), near-infrared magnetic circular dichroism (NIR-MCD) and resonance Raman (RR) spectroscopies at cryogenic temperatures has been used to identify the axial heme ligation of the low spin cytochrome b558 component of NADPH oxidase from porcine blood neutrophils. The EPR and NIR-MCD results indicate the presence of two distinct forms in frozen solution; one with a low field g-value at 3.23 and porphyrin(pi)-to-Fe(III) charge transfer maximum at 1660 nm and the other a low field g-value at 3.00 and porphyrin(pi)-to-Fe(III) charge transfer maximum at 1510 nm. On the basis of these properties and the RR studies, both are attributed to forms of cytochrome b558 with bis-histidine axial ligation. The origin of the observed heterogeneity, the location and identity of the specific histidines involved in ligating the heme, and the role of the heme prosthetic group in O2- production are discussed in light of these results.
在低温下，结合电子顺磁共振（EPR）、近红外磁圆二色性（NIR-MCD）和共振拉曼（RR）光谱技术，已用于鉴定猪血液中性粒细胞中NADPH氧化酶低自旋细胞色素b558组分的轴向血红素配体。EPR和NIR-MCD结果表明在冷冻溶液中存在两种不同的形式；一种在3.23处具有低场g值，在1660nm处卟啉（π）到Fe（III）电荷转移最大值，另一种在3.00处具有低场g值，在1510nm处卟啉（π）到Fe（III）电荷转移最大值。基于这些性质和RR研究，两者都归因于具有双组氨酸轴向配体的细胞色素b558形式。根据这些结果，讨论了观察到的异质性的起源、参与血红素连接的特定组氨酸的位置和身份，以及血红素辅基在O2-产生中的作用。
