# Protocol for identification of cell-surface proteins with horseradish peroxidase

## TL;DR

This paper presents a detailed protocol using horseradish peroxidase to identify cell-surface proteins in mouse brain cells for studying intercellular communication.

## Contribution

A new protocol for cell-type-specific proteomic profiling of cell-surface proteins in mice using horseradish peroxidase.

## Key findings

- The protocol includes AAV injection, biotinylation, and mass spectrometry for CSP identification.
- Systematic identification of CSPs involved in cell-cell interactions in health and disease is enabled.
- Steps for data processing and interpretation are provided.

## Abstract

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

•HRP-based proximity labeling approach to identify cell-surface proteins in mouse brain cells•A step-by-step HRP protocol including experimental design and protein identification•Guidance on data processing and interpretation

HRP-based proximity labeling approach to identify cell-surface proteins in mouse brain cells

A step-by-step HRP protocol including experimental design and protein identification

Guidance on data processing and interpretation

Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

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.