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PHOTOCHEMICALLY-ENHANCED BINDING OF SMALL MOLECULES TO THE TUMOR NECROSIS FACTOR RECEPTOR-1PHOTOCHEMICALLY-ENHANCED BINDING OF SMALL MOLECULES TO THE TUMOR NECROSIS FACTOR RECEPTOR-1
Structural highlights
DiseaseTNR1A_HUMAN Defects in TNFRSF1A are the cause of familial hibernian fever (FHF) [MIM:142680; also known as tumor necrosis factor receptor-associated periodic syndrome (TRAPS). FHF is a hereditary periodic fever syndrome characterized by recurrent fever, abdominal pain, localized tender skin lesions and myalgia. Reactive amyloidosis is the main complication and occurs in 25% of cases.[1] [2] [3] [4] [5] Genetic variation in TNFRSF1A is associated with susceptibility to multiple sclerosis 5 (MS5) [MIM:614810. A multifactorial, inflammatory, demyelinating disease of the central nervous system. Sclerotic lesions are characterized by perivascular infiltration of monocytes and lymphocytes and appear as indurated areas in pathologic specimens (sclerosis in plaques). The pathological mechanism is regarded as an autoimmune attack of the myelin sheat, mediated by both cellular and humoral immunity. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia and bladder dysfunction. Genetic and environmental factors influence susceptibility to the disease. Note=An intronic mutation affecting alternative splicing and skipping of exon 6 directs increased expression of isoform 4 a transcript encoding a C-terminally truncated protein which is secreted and may function as a TNF antagonist.[6] FunctionTNR1A_HUMAN Receptor for TNFSF2/TNF-alpha and homotrimeric TNFSF1/lymphotoxin-alpha. The adapter molecule FADD recruits caspase-8 to the activated receptor. The resulting death-inducing signaling complex (DISC) performs caspase-8 proteolytic activation which initiates the subsequent cascade of caspases (aspartate-specific cysteine proteases) mediating apoptosis. Contributes to the induction of non-cytocidal TNF effects including anti-viral state and activation of the acid sphingomyelinase. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe binding of tumor necrosis factor alpha (TNF-alpha) to the type-1 TNF receptor (TNFRc1) plays an important role in inflammation. Despite the clinical success of biologics (antibodies, soluble receptors) for treating TNF-based autoimmune conditions, no potent small molecule antagonists have been developed. Our screening of chemical libraries revealed that N-alkyl 5-arylidene-2-thioxo-1,3-thiazolidin-4-ones were antagonists of this protein-protein interaction. After chemical optimization, we discovered IW927, which potently disrupted the binding of TNF-alpha to TNFRc1 (IC(50) = 50 nM) and also blocked TNF-stimulated phosphorylation of Ikappa-B in Ramos cells (IC(50) = 600 nM). This compound did not bind detectably to the related cytokine receptors TNFRc2 or CD40, and did not display any cytotoxicity at concentrations as high as 100 microM. Detailed evaluation of this and related molecules revealed that compounds in this class are "photochemically enhanced" inhibitors, in that they bind reversibly to the TNFRc1 with weak affinity (ca. 40-100 microM) and then covalently modify the receptor via a photochemical reaction. We obtained a crystal structure of IV703 (a close analog of IW927) bound to the TNFRc1. This structure clearly revealed that one of the aromatic rings of the inhibitor was covalently linked to the receptor through the main-chain nitrogen of Ala-62, a residue that has already been implicated in the binding of TNF-alpha to the TNFRc1. When combined with the fact that our inhibitors are reversible binders in light-excluded conditions, the results of the crystallography provide the basis for the rational design of nonphotoreactive inhibitors of the TNF-alpha-TNFRc1 interaction. Photochemically enhanced binding of small molecules to the tumor necrosis factor receptor-1 inhibits the binding of TNF-alpha.,Carter PH, Scherle PA, Muckelbauer JK, Voss ME, Liu RQ, Thompson LA, Tebben AJ, Solomon KA, Lo YC, Li Z, Strzemienski P, Yang G, Falahatpisheh N, Xu M, Wu Z, Farrow NA, Ramnarayan K, Wang J, Rideout D, Yalamoori V, Domaille P, Underwood DJ, Trzaskos JM, Friedman SM, Newton RC, Decicco CP Proc Natl Acad Sci U S A. 2001 Oct 9;98(21):11879-84. PMID:11592999[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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