Amyloid-like protein structure in mammalian ocular lenses
Amyloid-like protein structure in mammalian ocular lenses
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DOI：
10.1076/0271-3683(200006)20:6;1-y;ft462
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发表时间：
2000-01-01
影响因子：
2
通讯作者：
Frederikse, PH
中科院分区：
文献类型：
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作者：
Frederikse, PH
目的。在过去的 30 年里，广泛的拉曼和红外光谱研究确定，正常哺乳动物晶状体中的主要蛋白质在体内主要以 β 折叠片形式存在。本研究检查了晶状体蛋白β-折叠片阵列中淀粉样蛋白超分子顺序的存在。方法。使用经典的淀粉样蛋白染色剂刚果红和硫黄素，使用明场显微镜原位鉴定具有淀粉样蛋白结构的晶状体区域。使用偏光显微镜测定刚果红染色镜片的双折射。还通过荧光显微镜检查了硫黄素染色的镜片，以检测指示硫黄素插入β-折叠淀粉样蛋白结构中的诊断性荧光红移。结果。主要发现是 1) 刚果红染色开始于晶状体内部的突然边界，与正常晶状体纤维细胞分化过程中发生的细胞生物学和物理环境的广泛重组相一致。 2) 刚果红染色镜片中的苹果绿双折射与淀粉样蛋白染料亲和力共定位。 3) 硫黄素从同一边界开始污染晶状体内部。 4) 在晶状体内部检测到硫黄素荧光的红移，该红移与无细胞器晶状体纤维中的淀粉样蛋白染料亲和力和双折射共定位。结论。目前的数据表明，淀粉样蛋白染料结合、硫黄素荧光的原位红移和苹果绿双折射提供了晶状体蛋白β-片层阵列在哺乳动物眼晶状体的内部纤维细胞中以类淀粉样蛋白超分子顺序组织的证据。淀粉样蛋白结构的固有稳定性可能有助于晶状体的长期结构完整性和透明度。
Purpose. Over the past 30 years, extensive Raman and infrared spectroscopy studies determined that the major proteins in normal mammalian lenses exist predominantly as beta-pleated sheets in vivo. The present study examines the presence of amyloid protein supramolecular order of lens protein beta-pleated sheet arrays.Methods. The classic amyloidophilic stains Congo red and thioflavine were used in situ to identify lens regions with amyloid protein structure using brightfield microscopy. Birefringence in Congo red stained lenses was determined using polarizing light microscopy. Thioflavine stained lenses were also examined by fluorescence microscopy to detect a diagnostic fluorescence red-shift indicative of the intercalation of thioflavine into beta-sheet amyloid protein structures.Results. The major findings are 1) Congo red staining begins in the lens interior at an abrupt boundary coinciding with the extensive reorganization of cell biology and physical environment that occurs during normal lens fiber cell differentiation. 2) Apple-green birefringence in Congo red stained lenses co-localizes with amyloidophilic dye affinity. 3) Thioflavine stains the lens interior beginning at the same boundary. 4) A red shift in thioflavine fluorescence was detected in the lens interior that co-localizes with amyloidophilic dye affinities and birefringence in organelle-free lens fibers.Conclusions. The present data demonstrating amyloidophilic dye binding, in situ red shift in thioflavine fluorescence, and apple-green birefringence provide evidence that lens protein beta-sheet arrays are organized in an amyloid-like supramolecular order in interior fiber cells of mammalian ocular lenses. The inherent stability of amyloid-like protein structure may contribute to the long-term structural integrity and transparency of the lens.