This peptide corresponds to the protein transduction domain of the TAT protein and is synthesized from activated cysteine residue C (Npys), where Npys is 3-nitro-2-pyridinesulfonyl, used to activate the S of cysteine And the rapid reaction when introducing sulfhydryl groups. This modification makes it a cell-penetrating and carrier peptide that can be used in binding studies.
1, Bright R. et al. Neurosci lett. 441, 120-124 (2008) 2, Moultin HM. Et al. Bioconj Chem. 15(2):290-299 (2004).