SHORT-RANGE ORDER OF CRYSTALLIN PROTEINS ACCOUNTS FOR EYE LENS TRANSPARENCY
SHORT-RANGE ORDER OF CRYSTALLIN PROTEINS ACCOUNTS FOR EYE LENS TRANSPARENCY
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DOI：
10.1038/302415a0
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发表时间：
1983-01-01
期刊：
影响因子：
64.8
通讯作者：
TARDIEU, A
中科院分区：
文献类型：
--
作者：
DELAYE, M;TARDIEU, A
在其正常状态下，尽管细胞质中存在高浓度的蛋白质（晶体），但眼睛透镜是透明的，先验地，可以预期其散射入射光的重要部分。早期，人们试图从单个散射体之间的空间相关性中找到解释。Trokel 1首先提出“透镜中蛋白质的高浓度必须伴随着接近次晶状态的局部有序程度”; Benedek 2随后提出，蛋白质的致密非晶包装将充分降低散射强度。然而，尽管对堆叠s3 -6的分子结构有了更好的理解，但它们的空间顺序仍然未知。我们在这里提出了一个小角度X射线散射研究的问题，进行与小牛透镜细胞质在完整的晶状体和细胞质提取物中的晶体蛋白浓度从3到510毫克毫升-1。我们所有的实验数据都与短程空间秩序一致，如在稠密液体或玻璃7 -9中，这为透镜的不对称性提供了一个简单的解释2，10。此外，我们没有检测到构象变化或重组的晶体蛋白的蛋白质在整个调查的浓度范围。
In its normal state, the eye lens is transparent despite the presence in the cell cytoplasm of high concentrations of proteins, the crystalline, which,a priori, could be expected to scatter an important part of the incident light. Early on, an explanation was sought in the spatial correlations between individual scatterers. Trokel1first proposed that the "high concentration of proteins in the lens must be accompanied by a degree of local order approaching a paracrystalline state"; Benedek2subsequently suggested that a dense, noncrystalline packing of the proteins would sufficiently reduce the scattered intensity. However, in spite of an improved understanding of the molecular structure of crystallins3–6, their spatial order remained unknown. We present here a small-angle X-ray scattering study of the problem, performed with calf lens cytoplasm both in intact lenses and in cytoplasmic extracts where the crystallin concentration was varied from 3 to 510 mg ml−1. All our experimental data are consistent with short-range spatial order, as in dense liquids or glasses7–9, and this provides a simple explanation for lens transparency2,10. In addition, we detected no conformational change or reorganization of the crystallin proteins throughout the investigated concentration range.