2.1.1 Acetylation
Acetylation is a process of transferring an acetyl group (-CH3CO) to a molecule, mainly to N- or O- atoms, known as N-acetylation or O-acetylation. Acetylation of His is recently reported for Histidine-Tyrosine (HY) and Tyrosine-Histidine (YH) dyads treated with acetic anhydride [10]. His undergoes N-acetylation at its imidazole ring.