Cheng A C, Hogan J L, Caffrey M
Department of Chemistry, Ohio State University, Columbus 43210-1173.
J Mol Biol. 1993 Jan 20;229(2):291-4. doi: 10.1006/jmbi.1993.1034.
Lipid membranes undergo a dramatic lamellar-to-non-lamellar phase transformation upon being irradiated with X-rays. The structure change was evidenced by chemical breakdown of the lipid and by a change in the X-ray diffraction properties of the model membrane indicating complete disruption of lamellar stacking. Considering the importance of X-ray diffraction as a structure probe the problem of radiation damage to biological materials must be duly recognized. Because X-ray damage has been shown to be free radical-mediated these results suggest a means by which free radicals accumulating in cells during aging might compromise membrane integrity and contribute to cell death.
脂质膜在受到X射线照射后会经历从片层到非片层的剧烈相变。脂质的化学分解以及模型膜X射线衍射特性的变化证明了结构的改变,这表明片层堆积完全被破坏。考虑到X射线衍射作为一种结构探测手段的重要性,必须充分认识到生物材料的辐射损伤问题。由于已证明X射线损伤是由自由基介导的,这些结果提示了一种机制,即衰老过程中细胞内积累的自由基可能会损害膜的完整性并导致细胞死亡。