RESUMEN
Lacquer tree sap, a raw material of traditional paints in East Asia, is hardened through laccase-catalyzed oxidation and the following polymerization of phenolic compound urushiol. In the sap's water-insoluble fraction, we found two plantacyanins and a ferritin 2 domain-containing protein (TvFe2D, a homolog of Arabidopsis AT1G47980 and AT3G62730). The recombinant TvFe2D protein suppressed the accumulation of laccase-catalyzed oxidation products of a model substrate syringaldazine without decreasing oxygen consumption, the second substrate of laccase. The suppression was also observed when another substrate guaiacol or another oxidizing enzyme peroxidase was used. The functional domain of the suppression was the C-terminal half, downstream of the ferritin 2 domain. The results suggest that this protein may be involved in regulating the sap polymerization/hardening. We also discuss the possibility that homologous proteins of TvFe2D in other plants might be involved in the laccase- or peroxidase-mediated polymerization of phenolic compounds, such as lignin and flavonoids.
Asunto(s)
Regulación de la Expresión Génica de las Plantas , Lacasa/metabolismo , Laca/análisis , Metaloproteínas/metabolismo , Peroxidasas/metabolismo , Proteínas de Plantas/metabolismo , Toxicodendron/metabolismo , Secuencia de Aminoácidos , Biocatálisis , Catecoles/metabolismo , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Ferritinas/química , Guayacol/metabolismo , Hidrazonas/metabolismo , Cinética , Lacasa/genética , Lignina/metabolismo , Metaloproteínas/genética , Oxidación-Reducción , Consumo de Oxígeno , Peroxidasas/genética , Proteínas de Plantas/genética , Polimerizacion , Dominios Proteicos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Especificidad por Sustrato , Toxicodendron/química , ÁrbolesRESUMEN
OBJECTIVES: To explore the short-term effects from toothbrushing, tongue cleaning with sponge brush and wiping on oral mucous membrane by chlorhexidine. BACKGROUND: Numerous reports have been seen in recent years proving the effectiveness of mouth cleaning with a toothbrush for the prevention of respiratory infections among the dependent elderly. However, the short-term effects from each oral care method have not yet been clarified. Hence, an investigation was conducted by having each subject independently perform various oral care methods for five consecutive days. MATERIALS AND METHODS: The subjects consisted of 12 assistance-dependent elderly who have difficulties with tooth brushing by themselves, have 10 or more residual teeth and are not yet using plate dentures. After the pre-intervention examination, each of the following oral care methods were performed on the same subject on an approximately three week basis: 1) Tooth brushing 2) Tongue cleaning with sponge brush 3) Wiping on oral mucous with sponge brush by chlorhexidine. Each method was performed independently, once a day for 5 consecutive days and the subjects were reexamined on the sixth day for comparative verification. RESULTS: Consequently, toothbrushing decreased the plaque index and gingival index significantly and an improvement of oral malodour was also acknowledged (p < 0.01). Tongue cleaning with a sponge brush decreased the tongue coat score significantly (p < 0.05) and oral malodour was also improved (p < 0.01). Wiping on oral mucous with a sponge brush soaked in chlorhexidine significantly decreased opportunistic infections in the pharynx region (p < 0.05). CONCLUSIONS: It was suggested that the use of not only a toothbrush but also chlorhexidine gluconate may be indicated for dependent elderly people in whom pathogens of opportunistic infection are detected.
