Methods: Measurements were performed using a rotating ring disk apparatus, dual potentiostat/galvanostat and a polarization cell. The cell included the tested pure metal as a rotating disk electrode, a counter electrode (Pt wire) and a reference electrode (Ag/AgCl, 3M NaCl). The electrolyte was TBS (pH=7.4, 80ml) containing the tested amino acid at a concentration of 0.01M. The measurements were performed at disk electrode rotational speed of 1000 rpm, scan rate of 0.05 V/sec, cyclic number of 3, and measurement n = 3.
Results: Reactions were observed between Lysine(K) and Ag, Cu, Pd, Ti, Sn, Cysteine(C) and Ag, Cu, Pd, Ni, Al, Sn, Zn, Proline (P) and Cu, Pd, Al, Ni, Zn and Arginine (R) and Ag, Cu, Pd, Ni, Ti, Al, Zn. Especially notable electrochemical reaction was between Ag and Cu in the presence of Cysteine in TBS. These results of cyclic voltammetry in the presence of Cystine in the solution showed remarkable oxidation and reduction peaks for Ag (oxidation peak; +0.21V and +0.19V, reduction peak; -0.01V and -0.18V) and Cu (oxidation peak; +0.06V, -0.17V and -0.19V, reduction peak; -0.12V and -0.3V), indicating a possibility of a generation of new products.
Conclusions: The results of this study suggest that the metals exhibiting high reaction with some amino acids may produce allergens for metal allergy.
This study was supported by JSPS KAKENHI Grant-in-Aid for Challenging Exploratory Research Number 23659927.