Transdermal Peptide Disulfide TFA (TD 1 Disulfide(peptide) TFA), an 11-amino acid peptide, specifically binds to the Na+/K+-ATPase beta-subunit (ATP1B1), predominantly interacting with its C-terminus. This compound is capable of enhancing the transdermal delivery of various macromolecules[1].

In the presence of Transdermal Peptide Disulfide, because of the specific binding of Transdermal Peptide Disulfide to ATP1B1, cells will upregulate the level of ATP1B1 to maintain function and structure; as a result, the expression of ATP1B1 increases. However, as time goes on, some Transdermal Peptide Disulfide molecules may be transported into cells by endocytosis; consequently, the expression of ATP1B1 then decreases. The interaction between Transdermal Peptide Disulfide and ATP1B1 changes not only the expression of ATP1B1, but also the localization of ATP1B1 and then the structure of the epidermal layer. This interaction can be attenuated by inhibitors or competitors, which would result in the reduced delivery of macromolecular drugs across the skin[1].