Photo-cross-linking (PXL) with alkyl diazirines can provide stringent distance restraints and offer insights into protein structures, but unambiguous identification of cross-linked residues hinders data interpretation. Here, the authors report a quantitative analysis of alkyl diazirine photo-cross-linking reactions and reveal a two-step mechanism, enabling selective targeting of buried polar residues.
- Yida Jiang
- Xinghe Zhang
- Chun Tang
