Genetically Encoded Biosensor HyPer as a Tool for Quantification of Intracellular Hydrogen Peroxide Concentrations

This mini-review systematizes information on methods for quantitative assessment of intracellular hydrogen peroxide concentration based on the use of a genetically encoded peroxide sensor HyPer. Two approaches are being considered: 1) calibration of the biosensor using exogenous hydrogen peroxide, based on assessing the rate of peroxide penetration into cells and intracellular peroxidase activity; 2) direct determination of the intracellular peroxide content, based on measuring the level of oxidation of the biosensor, the oxidation reaction constant and the reduction reaction constant of HyPer in the cells. The use of these methods makes it possible to solve a wide range of tasks in cellular redox biology — to determine the range of physiological and damaging concentrations of hydrogen peroxide in cells, to evaluate the effectiveness of the antioxidant defense system in various cellular compartments under conditions of oxidative stress, to determine the contribution of various enzymatic systems to the peroxidase activity of cells, and to characterize antioxidant defense systems in various biological contexts (in the process of cellular senescence, differentiation, reprogramming, during the development of pathologies). The described methods can be adapted for other genetically encoded hydrogen peroxide biosensors.