Principles, Evolution, and Applications of Proximity Labeling
Summary of Technology Comparison
| Category | BioID | APEX | HRP |
| Enzyme Activity | Biotin ligase | Peroxidase | Peroxidase |
| Labeling Target | Lysine | Electron-rich amino acids (Tyr, Trp, Cys, and His) | Electron-rich amino acids (Tyr, Trp, Cys, and His) |
| Size | BioID, AirID, TurboID: 35kDa BioID2: 24kDa miniTurboID: 28kDa BASU: 29kDa | APEX, APEX2: 27kDa | 44kDa |
| Labeling Time | BioID, BioID2: 15-24h AirID: 1-24h TurboID, miniTurboID: 10min | 1min | 5-10min |
| Incubation Time with Substrate | BioID, BioID2: 15-24h AirID: 3-24h TurboID, miniTurboID: 10min | 30-60min | 5-10min |
| H2O2 Activation | No | Yes | Yes |
| Substrate for Protein Labeling | Biotin | Biotin-phenol (Biotin-tyramide) Biotin-4-aminophenol Biotin-naphthylamine | - |
| Half-life of Free Radicals | Minutes | Less than 1 millisecond | Less than 1 millisecond |
| Active Area | Intracellular | Intracellular | Extracellular, secretory pathway (no activity in cytosol) |
| Notes | Can be used as an EM tag | Can be used as an EM tag; HRP-conjugated antibodies available | - |