Tang Chuanning, Lew Scott, He Dacheng
Key Laboratory of Cell Proliferation and Regulation of Ministry of Education, Beijing Normal University, Beijing, 100875, China.
Neotein Therapeutics, New York, New York, 10706, USA.
Protein Sci. 2016 Apr;25(4):898-904. doi: 10.1002/pro.2878. Epub 2016 Feb 11.
In vitro protein stability studies are commonly conducted via thermal or chemical denaturation/renaturation of protein. Conventional data analyses on the protein unfolding/(re)folding require well-defined pre- and post-transition baselines to evaluate Gibbs free-energy change associated with the protein unfolding/(re)folding. This evaluation becomes problematic when there is insufficient data for determining the pre- or post-transition baselines. In this study, fitting on such partial data obtained in protein chemical denaturation is established by introducing second-order differential (SOD) analysis to overcome the limitations that the conventional fitting method has. By reducing numbers of the baseline-related fitting parameters, the SOD analysis can successfully fit incomplete chemical denaturation data sets with high agreement to the conventional evaluation on the equivalent completed data, where the conventional fitting fails in analyzing them. This SOD fitting for the abbreviated isothermal chemical denaturation further fulfills data analysis methods on the insufficient data sets conducted in the two prevalent protein stability studies.
体外蛋白质稳定性研究通常通过蛋白质的热变性或化学变性/复性来进行。对蛋白质解折叠/（再）折叠的传统数据分析需要明确界定的转变前和转变后基线，以评估与蛋白质解折叠/（再）折叠相关的吉布斯自由能变化。当没有足够的数据来确定转变前或转变后基线时，这种评估就会出现问题。在本研究中，通过引入二阶微分（SOD）分析来对蛋白质化学变性中获得的此类部分数据进行拟合，以克服传统拟合方法存在的局限性。通过减少与基线相关的拟合参数数量，SOD分析能够成功地拟合不完整的化学变性数据集，且与对等效完整数据集的传统评估高度一致，而传统拟合在分析这些数据集时失败了。这种对简化等温化学变性的SOD拟合进一步完善了在两项普遍的蛋白质稳定性研究中对不完整数据集的数据分析方法。
