An equation to estimate the difference between theoretically predicted and SDS PAGE-displayed molecular weights for an acidic peptide.
An equation to estimate the difference between theoretically predicted and SDS PAGE-displayed molecular weights for an acidic peptide.
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用于估计酸性肽的理论预测分子量和 SDS PAGE 显示分子量之间差异的方程
DOI：
10.1038/srep13370
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发表时间：
2015-08-27
影响因子：
4.6
通讯作者：
Peng J
中科院分区：
文献类型：
--
作者：
Guan Y;Zhu Q;Huang D;Zhao S;Jan Lo L;Peng J
蛋白质的分子量（MW）可以根据其氨基酸（AA）组成来预测。然而，在许多情况下，非化学修饰的蛋白质在SDS page上显示的分子量比预测的大。一些报道将这一事实与蛋白质中酸性AA的高含量联系起来。然而，酸性AA组成与SDS - page显示的分子量之间的确切关系尚未确定。斑马鱼核核蛋白Def由753个AA组成，SDS - page显示的分子量比预测的分子量大约13 kDa。Def的前188个AA是由富含谷氨酸的区域定义的，其中含有~35.6%的酸性AA。在这篇报道中，我们分析了来自Def的13个肽的SDS - page显示的分子量与每个肽中的AA组成之间的关系。我们发现，预测值与SDS page显示的分子量之间的差异与酸性AA的百分比呈线性相关，符合方程=276.5x−31.33（x表示酸性AA的百分比，11.4%≤x≤51.1%；y表示平均ΔMW每AA）。我们证明，该方程可以应用于预测13种不同的天然酸性蛋白质的SDS - page显示的分子量。
The molecular weight (MW) of a protein can be predicted based on its amino acids (AA) composition. However, in many cases a non-chemically modified protein shows an SDS PAGE-displayed MW larger than its predicted size. Some reports linked this fact to high content of acidic AA in the protein. However, the exact relationship between the acidic AA composition and the SDS PAGE-displayed MW is not established. Zebrafish nucleolar protein Def is composed of 753 AA and shows an SDS PAGE-displayed MW approximately 13 kDa larger than its predicted MW. The first 188 AA in Def is defined by a glutamate-rich region containing ~35.6% of acidic AA. In this report, we analyzed the relationship between the SDS PAGE-displayed MW of thirteen peptides derived from Def and the AA composition in each peptide. We found that the difference between the predicted and SDS PAGE-displayed MW showed a linear correlation with the percentage of acidic AA that fits the equationy=276.5x−31.33(xrepresents the percentage of acidic AA, 11.4% ≤x≤ 51.1%;yrepresents the average ΔMW per AA). We demonstrated that this equation could be applied to predict the SDS PAGE-displayed MW for thirteen different natural acidic proteins.