Use Of Differential Sensing-Based Biosensors To Quantify Erk Kinase Activity In Complex Biological Samples

The expeditious quantification of signalling in complex biological system by novel technologies will aid in the development of biological models, help to identify targets for treatment, and assess treatment plans. The biochemical process of protein phosphorylation, which underlies almost all aspects of cell signaling, is typically evaluated by immunoblotting procedures like western blot. More recently, proteomics procedures, which provide qualitative estimates of the concentration of proteins and their modifications in cells have also been used. However, enzyme activity can be difficult to correlate to protein modifications.vRecently we reported a differential sensing-based approach to differentiate nine MAPKs from each other. From this we developed a cabilbration regression model to measure ERK activation and inhibition while both JNK and p38 MAPKs were present. Our previous studies were carried out using purified MAPKs, which do not necessarily reflect endogenous activity. Here, we report a similar approach to rapidly quantify unknown levels of endogenous ERK activity in biological samples. To do so, a library of cross-reactive SOX-peptide-based biosensors along with chemometric analysis, was used to quantify nanograms of active ERK in micrograms of unfractionated cell lysates and tumor extracts. This approach can be used to measure multiple samples quickly, allowing for faster analysis of the response of actual ERK activity in treatments in cell lines or animal models than other methods. This approach might also provide an alternative to assessing ERK activity in human tumor biopsies, which would be valuable for evaluating treatments and inhibitor resistance. Citation Format: Diana Zamora-Olivares, Jacey R. Pridgen, Lingyu Zeng, Tamer S. Kaoud, Eric V. Anslyn, Kevin N. Dalby. Use of differential sensing-based biosensors to quantify ERK kinase activity in complex biological samples [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6312.