中国物理B ›› 2016, Vol. 25 ›› Issue (4): 48701-048701.doi: 10.1088/1674-1056/25/4/048701
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
Mei-Juan Yu(于梅娟), Yu Wang(王宇), Wei Xu(徐伟)
Mei-Juan Yu(于梅娟)1, Yu Wang(王宇)2, Wei Xu(徐伟)1
摘要: The local configurations around metal ions in metalloproteins are of great significance for understanding their biological functions. Cu2+/histidine (His) is a typical complex existing in many metalloproteins and plays an important role in lots of physiological functions. The three-dimensional (3D) structural configurations of Cu2+/His complexes at different pH values (2.5, 6.5, and 8.5) are quantitatively determined by x-ray absorption near-edge structure (XANES). Generally Cu2+/His complex keeps an octahedral configuration consisting of oxygen atoms from water molecules and oxygen or nitrogen atoms from histidine molecules coordinated around Cu2+. It is proved in this work that the oxygen atoms from water molecules, when increasing the pH value from acid to basic value, are gradually substituted by the Ocarboxyl, Nam, and Nim from hisitidine molecules. Furthermore, the symmetries of Cu2+/His complexes at pH 6.5 and pH 8.5 are found to be lower than at pH 2.5.
中图分类号: (X-ray and EXAFS)