The use of dynamic light scattering and Brownian microscopy to characterize protein aggregation
The use of dynamic light scattering and Brownian microscopy to characterize protein aggregation
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DOI：
10.1063/1.3592581
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发表时间：
2011-05-01
影响因子：
1.6
通讯作者：
Vekilov, Peter G.
中科院分区：
文献类型：
--
作者：
Li, Ye;Lubchenko, Vassiliy;Vekilov, Peter G.
动态光散射（DLS）通常用于监测蛋白质溶液中的聚集。在这里，我们探索的聚集体尺寸，尺寸分布宽度，浓度和寿命的DLS结果的准确性。我们使用作为一个例子的蛋白质溶菌酶的解决方案，其中密集的液体团簇的半径约100 nm的可再现地存在。我们比较的结果DLS的布朗显微镜。我们发现，由于散射光强度对散射体大小的六次方依赖性，DLS高估了团簇的平均大小。高估因子取决于粒度分布的形状，与研究溶液中的1.6 x相似。团簇浓度的相关低估类似于10 x。CONTIN算法通常用于处理DLS数据，在某些情况下可能会产生非物理结果。我们提出了一种替代的方法来确定聚集体的尺寸，浓度和体积分数。我们发现，只有当团簇浓度大于10（9）cm（-3）且体积分数大于10（-6）时，DLS才能得到可靠的团簇尺寸分布宽度。DLS产生的集群寿命的下限，这可能是数量级低于真实的一个。(C)2011年美国物理学会。[doi：10.1063/1.3592581]
Dynamic light scattering (DLS) is often used to monitor aggregation in protein solutions. Here, we explore the veracity of the aggregate sizes, size distribution widths, concentrations, and lifetime resulting from DLS. We use as an example a solution of the protein lysozyme in which dense liquid clusters of radius about 100 nm reproducibly exist. We compare the results of DLS to those of Brownian microscopy. We show that because of the sixth power dependence of the scattered light intensity on the size of the scatterers, DLS overestimates the mean size of the clusters. The factor of overestimation depends on the shape of the size distribution and is similar to 1.6 x in the studied solution. The related underestimate of the cluster concentration is similar to 10 x. The CONTIN algorithm, often employed to process DLS data, may, in some instances, produce non-physical results. We put forth an alternative method to determine the aggregates' sizes, concentrations, and volume fractions. We show that DLS yields a reliable width of the cluster size distribution only if the cluster concentration is above 10(9) cm(-3) and their volume fraction is above 10(-6). DLS yields a lower bound of the cluster lifetime, which may be orders of magnitude lower than the real one. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3592581]