Conformational characterization of oligomeric intermediates and aggregates in β-lactoglobulin heat aggregation
Conformational characterization of oligomeric intermediates and aggregates in β-lactoglobulin heat aggregation
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DOI：
10.1110/ps.42501
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发表时间：
2001-07-01
期刊：
影响因子：
8
通讯作者：
Rischel, C
中科院分区：
文献类型：
--
作者：
Carrotta, R;Bauer, R;Rischel, C
在蛋白质聚集中分离中间体的首批研究之一中，我们使用圆二色性和荧光光谱来表征在 β-乳球蛋白热聚集的早期步骤中形成的亚稳态低聚物。中间体表现出典型的熔球特征（二级结构含量类似于侧链的天然且不太紧密的堆积），这与部分折叠状态在蛋白质聚集中发挥关键作用的观点一致。远紫外 CD 信号与已知的折叠中间体的信号非常相似。聚集体的冷冻透射电子显微镜显示出直径约为 50 nm 的球形颗粒和内部丝状结构。分离的低聚物以及较大的聚集体与染料硫代黄素 T 结合，这通常是许多蛋白质聚集体中发现的淀粉样蛋白超结构的特征。该结果表明硫黄素T识别的结构基序可以形成小寡聚物。
In one of the first studies of isolated intermediates in protein aggregation, we have used circular dichroism and fluorescence spectroscopy to characterize metastable oligomers that are formed in the early steps of beta -lactoglobulin heat aggregation. The intermediates show typical molten globule characteristics (secondary structure content similar to the native and less tight packing of the side chains), in agreement with the belief that partly folded states play a key role in protein aggregation. The far-UV CD signal bears strong resemblance to that of a known folding intermediate. Cryo-transmission electron microscopy of the aggregates reveals spherical particles with a diameter of about 50 nm and an internal threadlike structure. Isolated oligomers as well as larger aggregates bind the dye thioflavin T, usually a signature of the amyloid superstructures found in many protein aggregates. This result suggests that the structural motif recognized by thioflavin T can be formed in small oligomers.