Figure 3. 4-hydroxy-2-trans-nonenal (HNE) adduction of lysine, histidine, and cysteine.
HNE is a membrane diffusible, highly reactive alkenal species (formed by oxidation of arachidonic acid) that can readily oxidize other biomolecules, contributing to AD neurotoxicity [19]. HNE can covalently binds to lysine, histidine, and cysteine residues of proteins via Michael addition, forming adducts that are known to change the structural conformation [21] and function of proteins [14, 22, 23]. Resultant HNE-adduct structures with Lys, His, and Cys are shown.