食品科学

• 基础研究 • 上一篇    下一篇

猪心肌高铁肌红蛋白高级结构动态信息的光谱指认

李亚东1,吴名草1,汤 宇1,金邦荃1,*,黄鹤勇2,李 钢2,冯玉英2   

  1. 1.南京师范大学金陵女子学院,江苏 南京 210097;2.南京师范大学分析测试中心,江苏 南京 210097
  • 出版日期:2016-05-15 发布日期:2016-05-18

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

LI Yadong1, WU Mingcao1, TANG Yu1, JIN Bangquan1,*, HUANG Heyong2, LI Gang2, FENG Yuying2   

  1. 1. Ginling College, Nanjing Normal University, Nanjing 210097, China;
    2. Center of Analysis and Testing, Nanjing Normal University, Nanjing 210097, China
  • Online:2016-05-15 Published:2016-05-18

摘要:

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。

关键词: 单斜晶体, 结构域, 动态结构信息, 光谱特征, 猪心肌高铁肌红蛋白

Abstract:

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.

Key words: monoclinic crystal, structural domain, dynamic structural information, spectral characteristics, porcine myocardial metmyoglobin (pMetMb)

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