title: Direct covalent modification as a strategy to inhibit nuclear factor-kappa B.
abstract: Nuclear Factor-KkappaB (NF-kappaB) is a transcription factor whose inappropriate activation may result in the development of a number of diseases including cancer, inflammation, neurodegeneration and AIDS. Recent studies on NF-kappaB mediated pathologies, made therapeutic interventions leading to its inhibition an emerging theme in pharmaceutical research. NF-kappaB resides in the cytoplasm and is activated by several time-dependent factors, leading to proteasome-dependent degradation of its inhibitory protein (IkappaB), resulting in free NF-kappaB (p50 and p65 subunits, involved in disease states), which binds to target DNA sites, further resulting in enhanced transcription of several disease associated proteins. The complex pathway of NF-kappaB, finally leading to its DNA binding, has attracted several approaches interfering with this pathway. One such approach is that of a direct covalent modification of NF-kappaB. In this article, we present a critical review on the pharmacological agents that have been studied as inhibitors of NF-kappaB by covalently modifying redox-regulated cysteine residues in its subunits, ultimately resulting in the inhibition of kappaB DNA recognition and binding. Beginning with a general overview of NF-kappaB pathway and several possibilities of chemical interventions, the significance of redox-regulation in NF-kappaB activation and DNA binding is presented. Further, protein S-thiolation, S-nitrosylation and irreversible covalent modification are described as regular biochemical events in the cell, having provided a guideline for the development of NF-kappaB inhibitors discussed further. Although just a handful of inhibitors, with most of them being alkylating agents have been studied in the present context, this approach presents potential for the development of a new class of NF-kappaB-inhibitors.
authors.affiliation: Departamento de Química, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: Vineet
authors.initials: V
authors.lastname: Pande
authors.forename: Sérgio F
authors.initials: SF
authors.lastname: Sousa
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Ramos
mesh_terms: D000477:Alkylating Agents / Q000737:chemistry / Q000494:pharmacology; D003545:Cysteine / Q000737:chemistry; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015538:Nitrosation; D010084:Oxidation-Reduction; D011499:Protein Processing, Post-Translational; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D000477:Alkylating Agents; D016328:NF-kappa B; D013438:Sulfhydryl Compounds; D003545:Cysteine