猪心肌高铁肌红蛋白高级结构动态信息的光谱指认

本实验采用扫描电子显微镜、X射线衍射、拉曼、红外等现代光谱技术和数据库、计算软件等，层层剖析猪心肌高铁肌红蛋白（pig metmyoglobin，pMetMb）冻干粉的结构特征和分子动态结构信息。结果表明，pMetMb冻干粉表观呈明显的棱状结晶体，结晶度为（95.60±1.37）%，三晶胞轴长不相等（a≠b≠c），可归属于高晶度含水单斜结晶体。根据晶体数据库同类化合物比对，得到pMetMb肽链和heme-Fe的关键基团来源；经拉曼和红外光谱解析和推算，pMetMb肽链均有α螺旋、β折叠、β转角和无规卷曲4 种蛋白质二级结构，分别占50%、14%、24%和12%；分别由3 个酰胺区中C=O、C=C、C-N、-COO－、C-H、N-H的不同振动形式所产生；六配位低自旋的Fe-C-N形成heme-Fe3+。因此，pMetMb为六配位低自旋构象，是结构紧密、性质稳定的球状蛋白质。

Spectral Assignment of Dynamic Structure Information of Porcine Myocardial Metmyoglobin (pMetMb)

The dynamic molecular structures and domains of porcine myocardial metmyoglobin (pMetMb) were studied
and analyzed by scanning electron microscopy, X-ray diffraction, Raman and Infrared spectroscopy with matched databases
and softwares. Obviously prismatic crystalline structures were observed on the surface of lyophilized pMetMb powder. The
crystallinity of pMetMb was (95.60 ± 1.37)%, and it was highly crystalline and monoclinic powder because the lengths of its
three-dimensional unit cell were inequality (a ≠ b ≠ c). By comparison with crystal databases the source of heme-Fe domain
in pMetMb was identified. The Raman and Infrared spectra proved that the peptide chain of pMetMb contained 50% α-helix,
14% β-fold, 24% β-turn and 12% random coil, which came from the different shake forms C=O, C=C, C－N, －COO-,
C－H and N－H in the amide I, II and III regions. The heme-Fe domain in pMetMb formed by imidazole group (C3H4N2)
binding with Fe3+. So it belonged to globin with compact structure and stable properties.