Photochemical cross-linking of beta-galactoside-binding lectin to polylactosamino-proteoglycan of chick embryonic skin.

beta-Galactoside-binding lectin from chick embryonic skin was coupled with a new photoactivatable, radioactive cross-linking reagent, [35S]N-succinimidyl-3 [(2-nitro-4-azidophenyl)-2-aminoethyldithio] propionate, and was allowed to interact with an insoluble preparation from skin. After UV irradiation, the lectin was specifically cross-linked to a high-molecular-weight substance, which was degraded by endo-beta-galactosidase and pronase. This suggests that the endogenous receptor is polylactosamino-proteoglycan. The interaction between the lectin and polylactosaminoglycan has implications for the role of the lectin in embryonic differentiation.