Protocol for identification of cell-surface proteins with horseradish peroxidase

Cell-surface proteins (CSPs) play a central role in intercellular communication. Here, we outline a protocol for the cell-type-specific proteomic profiling of CSPs in mice based on horseradish peroxidase (HRP). We describe steps for adeno-associated virus (AAV) injection, biotinylation reaction, tissue homogenization, streptavidin pull-down, and mass spectrometry characterization, followed by quality control and data interpretation. This approach enables systematic identification of CSPs underlying cell-cell interactions in health and disease. For complete details on the use and execution of this protocol, please refer to Wu et al.¹.