Sinclair R, Copeland B, Yamazaki I, Powers L
National Center for the Design of Molecular Function, Utah State University, Logan 84322-4630, USA.
Biochemistry. 1995 Oct 10;34(40):13176-82. doi: 10.1021/bi00040a032.
The iron heme and its immediate environment can provide information that is pivotal to our understanding of the structural and mechanistic features that confer unusual properties to the heme peroxidases. X-ray absorption spectroscopy (XAS), which is ideally suited for the investigation of the local environment and electronic structure of the heme iron of hemeproteins, has been used to characterize a variety of lignin peroxidase and manganese-dependent peroxidase isoenzymes produced by the white rot fungus Phanerochaete chrysosporium. The data suggest no differences within the error in the first coordination shell of iron for the isoenzymes H2, H3, H4, H5, H8, and H10 examined in this study. The pyrrole nitrogens are at a distance of 2.05 +/- 0.015 A, and the proximal histidine nitrogens are at 1.93 +/- 0.02 A, while the sixth ligands are located at 2.17 +/- 0.03 A. Significant differences are observed in higher coordination shells which may be related to conformational differences in the heme.
铁血红素及其紧邻环境能够提供一些信息，这些信息对于我们理解赋予血红素过氧化物酶独特性质的结构和机制特征至关重要。X射线吸收光谱法（XAS）非常适合用于研究血红素蛋白中血红素铁的局部环境和电子结构，已被用于表征由白腐真菌黄孢原毛平革菌产生的多种木质素过氧化物酶和锰依赖过氧化物酶同工酶。数据表明，在本研究中检测的H2、H3、H4、H5、H8和H10同工酶的铁的第一配位层内，在误差范围内没有差异。吡咯氮原子距离为2.05±0.015 Å，近端组氨酸氮原子距离为1.93±0.02 Å，而第六个配体位于2.17±0.03 Å。在更高的配位层中观察到显著差异，这可能与血红素的构象差异有关。
