Comparison of the structures of the cubic and tetragonal forms of horse-spleen apoferritin
Comparison of the structures of the cubic and tetragonal forms of horse-spleen apoferritin
复制标题
DOI：
10.1107/s0907444997003314
复制
发表时间：
1997-09-01
影响因子：
2.2
通讯作者：
Precigoux, G
中科院分区：
文献类型：
--
作者：
Granier, T;Gallois, B;Precigoux, G
已知马脾脱铁铁蛋白以三种不同空间群结晶，立方F-432、四方P42（1）2和正交P2（1）2（1）2。本文给出了立方和四面体形式的结构比较。通过气相扩散技术获得两种晶型，并在2.26埃（立方晶体）和2.60埃（四方晶体）分辨率下收集数据。在这些晶体结构之间观察到两个主要差异：（i）尽管分子间接触仅涉及通过立方结构中的镉离子的盐桥型相互作用，在四方晶系中观察到两种类型的相互作用（镉离子介导的盐桥和氢键相互作用）和（ii）在铁蛋白分子的三重轴中结合的镉离子表现出较低的位点-占据因子在四面体结构中比在立方结构中高。
Horse-spleen apoferritin is known to crystallize in three different space groups, cubic F-432, tetragonal P42(1)2 and orthorhombic P2(1)2(1)2. A structure comparison of the cubic and tetragonal forms is presented here. Both crystal forms were obtained by the vapor-diffusion technique and data were collected at 2.26 Angstrom (cubic crystal) and 2.60 Angstrom (tetragonal crystal) resolution. Two main differences were observed between these crystal structures: (i) whereas intermolecular contacts only involve salt-bridge type interactions via cadmium ions in the cubic structure, two types of interactions are observed in the tetragonal crystal (cadmium-ion-mediated salt bridges and hydrogen-bonding interactions) and (ii) cadmium ions bound in the threefold axes of ferritin molecules exhibit lower site-occupation factors in the tetragonal structure than in the cubic one.