title: Effect of natural and semisynthetic pseudoguianolides on the stability of NF-κB:DNA complex studied by agarose gel electrophoresis.
abstract: The nuclear factor κB (NF-κB) is a promising target for drug discovery. NF-κB is a heterodimeric complex of RelA and p50 subunits that interact with the DNA, regulating the expression of several genes; its dysregulation can trigger diverse diseases including inflammation, immunodeficiency, and cancer. There is some experimental evidence, based on whole cells studies, that natural sesquiterpene lactones (Sls) can inhibit the interaction of NF-κB with DNA, by alkylating the RelA subunit via a Michael addition. In the present work, 28 natural and semisynthetic pseudoguianolides were screened as potential inhibitors of NF-κB in a biochemical assay that was designed using pure NF-κB heterodimer, pseudoguianolides and a ~1000 bp palindromic DNA fragment harboring two NF-κB recognition sequences. By comparing the relative amount of free DNA fragment to the NF-κB - DNA complex, in a routine agarose gel electrophoresis, the destabilizing effect of a compound on the complex is estimated. The results of the assay and the following structure-activity relationship study, allowed the identification of several relevant structural features in the pseudoguaianolide skeleton, which are necessary to enhance the dissociating capacity of NF-κB-DNA complex. The most active compounds are substituted at C-3 (α-carbonyl), in addition to having the α-methylene-γ-lactone moiety which is essential for the alkylation of RelA.
authors.affiliation: Centre for Analysis and Synthesis, Lund University, P.O. Box 124, 221 00 Lund, Sweden; Instituto de Investigaciones Químicas, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, P.O. Box 303 La Paz, Bolivia.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Villagomez
authors.affiliation: Biotechnology, Dept. of Chemistry, Lund University, P.O. Box 124, SE-22 100 Lund, Sweden.
authors.forename: Rajni
authors.initials: R
authors.lastname: Hatti-Kaul
authors.affiliation: Centre for Analysis and Synthesis, Lund University, P.O. Box 124, 221 00 Lund, Sweden.
authors.forename: Olov
authors.initials: O
authors.lastname: Sterner
authors.affiliation: Instituto de Investigaciones Químicas, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, P.O. Box 303 La Paz, Bolivia.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Almanza
authors.affiliation: Biotechnology, Dept. of Chemistry, Lund University, P.O. Box 124, SE-22 100 Lund, Sweden.
authors.forename: Javier A
authors.initials: JA
authors.lastname: Linares-Pastén
mesh_terms: D004247:DNA / Q000138:chemical synthesis*; D004587:Electrophoresis, Agar Gel; D006801:Humans; D055029:Inverted Repeat Sequences; D052002:NF-kappa B p50 Subunit / Q000737:chemistry*; D051996:Transcription Factor RelA / Q000737:chemistry*
chemical_list: D052002:NF-kappa B p50 Subunit; C489548:NFKB1 protein, human; C498143:RELA protein, human; D051996:Transcription Factor RelA; D004247:DNA