Updated project metadata.
The membrane proteins are essential targets to understand cellular function. The unbiased identification of membrane protein targets is still the bottleneck for a system- level understanding of cellular response to stimuli or perturbations. It has been suggested to enrich the soluble proteome with membrane proteins by introducing nonionic surfactants in the solubilization solution. This strategy was aiming to simultaneous identify the globular and membrane protein targets by thermal proteome profiling principles. However, the thermal shift assay would surpass the cloud point temperature from the nonionic surfactants most frequently utilized for membrane protein solubilization. It is expected that around the cloud point temperature, the surfactant micelles would suffer structural modifications altering the proteome solubility. Here, we show that the presence of nonionic surfactants can alter protein thermal stability from a mixed globular, and membrane proteome. In the presence of surfactant micelles, the changes in protein solubility analyzed after the thermal shift assay are affected by the thermal dependent modification of the micelles size, and their interaction with proteins. We demonstrate that the introduction of nonionic surfactants for the solubilization of membrane proteins is not compatible with the principles of target identification by thermal proteome profiling methodologies. Our results lead to explore thermal-independent strategies for membrane protein solubilization to assure confident membrane protein target identification. The proteome-wide thermal shift methods have already shown their capability to elucidate mechanism of actions from pharma, biomedicine, analytical chemistry, or toxicology and finding strategies, free from surfactants, to identify membrane protein targets would be the next challenge.