RESUMO
Experiments were undertaken to isolate a component of the serum of goat (Capra hircus) that is effective at mediating an innate immune response. This report describes the isolation and structure elucidation of 1-(N-acetyl-ALYDKGYTSKEQKDCVGI)-2-arachidonoyl-3-stearoyl glyceride (1) and its immunomodulatory activity. A dose-response relationship for inflammatory cytokine and chemokine production and release from human fibroblasts incubated with nanomolar concentrations of 1 was shown. Moreover, the membrane transport role of the diacylglycerol moiety in 1 is demonstrated with nanomolar quantities of the transfected N-acetyl peptide moiety of 1 also inducing inflammatory cytokine and chemokine production and release. The apparent EC99 for 1 was 3 ng/mL (1 nM). The likely biological role for naturally occurring 1 as a damage-associated molecular pattern is postulated.
Assuntos
Fatores Imunológicos/isolamento & purificação , Fatores Imunológicos/farmacologia , Lipopeptídeos/isolamento & purificação , Lipopeptídeos/farmacologia , Sequência de Aminoácidos , Animais , Animais Domésticos , Relação Dose-Resposta a Droga , Cabras , Humanos , Fatores Imunológicos/química , Fatores Imunológicos/toxicidade , Interleucina-8/análise , Lipopeptídeos/química , Lipopeptídeos/toxicidade , Estrutura Molecular , Homologia de Sequência do Ácido Nucleico , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Indium(II) iodide reacts with various substituted o-quinones in nonaqueous solution by successive one-electron-transfer reactions to give (SQ)InI(2) products (SQ = semiquinonate radical anion). Electron spin resonance spectroscopy demonstrates the presence of both mono- and diradical species in the reaction mixture. Addition of 4-picoline to a mixture of In(2)I(4) and TBQ (=3,5-di-tert-butyl-o-quinone) in toluene causes the precipitation of the indium(III)-semiquinonate complex (TBSQ)InI(2)(pic)(2) whose structure has been established by X-ray crystallography: space group P&onemacr;, with a = 13.013(3) Å, b = 13.317(3) Å, c = 10.828(5) Å, alpha = 97.71(3) degrees, beta = 107.98(3) degrees, gamma = 103.92(3) degrees, V = 1684.8(1.2) Å(3), Z = 2. Refinement converged at R = 0.051 and R(w) = 0.064 for 5918 reflections at 23 degrees C. The InO(2)N(2)I(2) kernel is pseudooctahedral, and the structure confirms the presence of the semiquinonate ligand. A reaction scheme which incorporates these results is proposed.
