Various cellular proteins (covalent adducts)

Various cellular proteins (covalent adducts) refers to the non-specific or multi-target covalent binding of reactive drug metabolites or electrophilic compounds to cellular proteins. This process, often termed protein haptenization, involves the formation of stable chemical bonds between a drug (or its metabolite) and nucleophilic functional groups on proteins, such as the sulfhydryl group of cysteine or the amino group of lysine (Park et al., 1998). While some therapeutic agents like dimethyl fumarate utilize this mechanism to modulate redox-sensitive pathways, it is more commonly associated with adverse drug reactions and idiosyncratic toxicities (Linker et al., 2011). For instance, the hepatotoxicity of acetaminophen is driven by the covalent binding of its reactive metabolite, N-acetyl-p-benzoquinone imine (NAPQI), to various mitochondrial and cytosolic proteins, leading to cellular dysfunction and death (James et al., 2003). Consequently, this target represents a significant challenge in drug development due to the potential for off-target effects and immune-mediated hypersensitivity. In pharmacological databases, this entry often serves as a collective term for drugs whose primary interaction involves broad chemical modification of the proteome rather than binding to a single specific receptor or enzyme.

Other names

Protein adductsCovalent protein bindingHapten-protein complexesDrug-protein adducts

Covalent modification of nucleophilic amino acid residues (e.g., cysteine, lysine) on various cellular proteins.