Harkness R W, Slavkovic S, Johnson P E, Mittermaier A K
Department of Chemistry, McGill University, 801 Sherbrooke St. W., Montreal QC H3A 0B8, Canada.
Department of Chemistry, York University, 4700 Keele Street, Toronto ON M3J 1P3, Canada.
Chem Commun (Camb). 2016 Nov 10;52(92):13471-13474. doi: 10.1039/c6cc05576a.
Differential scanning calorimetry (DSC) is a powerful technique for measuring tight biomolecular interactions. However, many pharmaceutically relevant ligands are chemically unstable at the high temperatures used in DSC analyses. Thus, measuring binding interactions is challenging because the concentrations of ligands and thermally-converted products are constantly changing within the calorimeter cell. Using experimental data for two DNA aptamers that bind to the thermolabile ligand cocaine, we present a new global fitting analysis that yields the complete set of folding and binding parameters for the initial and final forms of the ligand from a pair of DSC experiments, while accounting for the thermal conversion. Furthermore, we show that the rate constant for thermolabile ligand conversion may be obtained with only one additional DSC dataset.
差示扫描量热法（DSC）是一种用于测量紧密生物分子相互作用的强大技术。然而，许多与药物相关的配体在DSC分析所使用的高温下化学性质不稳定。因此，测量结合相互作用具有挑战性，因为配体和热转化产物的浓度在量热计池中不断变化。利用两种与热不稳定配体可卡因结合的DNA适体的实验数据，我们提出了一种新的全局拟合分析方法，该方法通过一对DSC实验得出配体初始和最终形式的完整折叠和结合参数集，同时考虑热转化。此外，我们表明，仅通过一个额外的DSC数据集就可以获得热不稳定配体转化的速率常数。
