Figure 3: Observed adduct formation in the reactivity experiments with isothiocyanates (0.5 mM), cysteine peptide (0.5 mM), and lysine peptide (0.5 mM).
From: Peptide Reactivity of Isothiocyanates – Implications for Skin Allergy

The level of cysteine peptide adduct is decreasing while the lysine peptide adduct concentration is increasing over time: (a) 6-TRITC, (b) PITC, and (c) EITC.