Catalyst-proximity protein chemical labelling on affinity beads targeting endogenous lectins.

Magnetic affinity beads functionalized with lactose and ruthenium/dcbpy complexes were developed. Using MAUra, a catalyst-proximity labelling reagent, the catalytic labeling of lactose-binding proteins was achieved with high selectivity on the beads. The first unbiased identification of cellular endogenous lectins bound to lactose (galectin-1 and galectin-3) was achieved with chemical labelling on the affinity beads.