Cellular proteins and other macromolecules with nucleophilic residues

Cellular proteins and other macromolecules with nucleophilic residues represent a broad class of biological targets characterized by electron-rich functional groups, such as the thiol group of cysteine, the amino group of lysine, and the nitrogen atoms in DNA bases (Nature Reviews Drug Discovery, 2011). These residues are susceptible to attack by electrophilic compounds, leading to the formation of stable covalent bonds. This interaction is the fundamental mechanism for many traditional chemotherapeutic alkylating agents, which cross-link DNA to inhibit replication and induce cell death in rapidly dividing cancer cells (StatPearls, 2023). In proteins, covalent modification can irreversibly inhibit enzymatic activity or disrupt critical signaling pathways, a strategy used by modern targeted covalent inhibitors (TCIs) (PubMed, 2018). However, the inherent reactivity of these agents toward various cellular nucleophiles often results in non-specific binding across the proteome. This lack of specificity can lead to significant safety concerns, including genotoxicity, myelosuppression, and the development of secondary malignancies (NIH, 2022). Consequently, while highly effective in treating cancer and autoimmune disorders, drugs targeting these residues require careful management of systemic toxicity.

Other names

Nucleophilic cellular targetsBiological nucleophilesProtein and DNA nucleophilesCellular electrophile targets

Drugs targeting these residues typically act through covalent modification, where an electrophilic drug molecule forms a permanent chemical bond with a nucleophilic site on a protein or nucleic acid (Nature Reviews Drug Discovery, 2011). This process, often involving alkylation, acylation, or phosphorylation, results in the irreversible inactivation of enzymes, structural proteins, or the cross-linking of DNA strands, thereby halting cellular processes such as replication and transcription (StatPearls, 2023).