description

The linkage of a drug to its carrier via a disulfide-based self-immolative linker allows for the specific intracellular release of the active molecule upon glutathione reduction and linker cleavage. The overall red/ox potential in the human blood is oxidative, making disulfide linkages stable during circulation. In contrast, the intracellular milieu of mammalian cells is characterized by an overall reductive potential, thus allowing to revert the disulfide bond formation. Pyridyl disulfides undergo a disulfide exchange reaction with sulfhydryl groups to form disulfide bonds over a broad pH range also suitable for physiological pH. During the reaction, a disulfide exchange occurs between the biomolecule’s thiol group and the reagent’s 2-pyridyldithiol group. As a result, pyridine-2-thione is released, which can be followed spectrophotometrically (λmax = 343 nm) to monitor the progress of the reaction. The p-nitrophenylcarbonate activating group reacts preferably with amines or other nucleophiles and allows further derivatization, e.g. with the desired drug molecule.

references

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