ULTRASTRUCTURE OF FERRITIN MACROMOLECULES - LATTICE STRUCTURE OF CORE CRYSTALLITES
ULTRASTRUCTURE OF FERRITIN MACROMOLECULES - LATTICE STRUCTURE OF CORE CRYSTALLITES
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DOI：
10.1073/pnas.70.12.3847
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发表时间：
1973-01-01
影响因子：
11.1
通讯作者：
COWLEY, JM
中科院分区：
文献类型：
--
作者：
MASSOVER, WH;COWLEY, JM
本文用100千伏高分辨电子显微镜观察了构成铁蛋白大分子中心核的结晶铁矿物的超微结构。非常高的放大率暗场图像揭示了在许多核心内存在单个大晶体或几个较小的微晶。当高度结晶的核内容物被适当地定向以使它们的布拉格反射通过物镜孔径时，已经观察到间隔为2-9.5 μ m的规则条纹。晶格条纹的几何关系和这些单个微晶中周期性组织的点细节的几何关系在很大程度上证实了托和布拉德利（1967）提出的结构模型。铁离子在晶格的某些平面中的高度可变的占据表明，完全饱和的铁蛋白的铁含量的20-33%应该经历比其余部分更快的生理释放，并且铁吸收将具有依赖于不仅仅是最大结晶速率的动力学。
The ultrastructure of the crystalline ferric mineral that forms the central core of ferritin macro-molecules has been examined by means of ultrahigh resolution electron microscopy at 100 kV. Very high magnification dark-field images reveal the presence of either a single large crystal or several smaller crystallites within many of the cores. When the highly crystalline core contents are suitably oriented to transmit their Bragg reflections through the objective aperture, regular fringes separated by 2-9.5 Å have been visualized. The geometrical relations of lattice fringes and of periodically organized point details in these individual crystallites largely confirm the structural model proposed by Towe and Bradley (1967). The highly variable occupancy of ferric ions in certain planes of the lattice suggests that 20-33% of the iron content of fully saturated ferritin should undergo more rapid physiological release than does the remainder, and that iron uptake will have kinetics that depend upon more than only the maximal rate of crystallization.