Mitochondrial DNA(mtDNA) common deletion(CD) plays a significant role in aging and age-related diseases.In this study,we used D-galactose(D-gal) to generate an animal model of aging and the involvement and causative m...Mitochondrial DNA(mtDNA) common deletion(CD) plays a significant role in aging and age-related diseases.In this study,we used D-galactose(D-gal) to generate an animal model of aging and the involvement and causative mechanisms of mitochondrial damage in such a model were investigated.Twenty 5-week-old male Sprague-Dawley rats were randomly divided into two groups:D-gal group(n=10) and control group(n=10).The quantity of the mtDNA CD in the hippocampus was determined using a TaqMan real-time PCR assay.Transmission electron microscopy was used to observe the mitochondrial ultrastructure in the hippocampus.Western blot was used to detect the protein levels of NADPH oxidase(NOX) and uncoupling protein 2(UCP2).We found that the level of mtDNA CD was significantly higher in the hippocampus of D-gal-induced aging rats than in control rats.In comparison with the control group,the mitochondrial ultrastructure in the hippocampus of D-gal-treated rats was damaged,and the protein levels of NOX and UCP2 were significantly increased in the hippocampus of D-gal-induced aging rats.This study demonstrated that the levels of mtDNA CD and NOX protein expression were significantly increased in the hippocampus of D-gal-induced aging rats.These findings indicate that NOX-dependent reactive oxygen species generation may contribute to D-gal-induced mitochondrial damage.展开更多
A mononuclear copper(II) complex, [Cu(bipy)(naph)(ClO4)] (where bipy is bipyridine and naph is 2-hydroxy-1-naphthaldehyde), was synthesized and characterized by X-ray single-crystal structure analysis. The crystal is ...A mononuclear copper(II) complex, [Cu(bipy)(naph)(ClO4)] (where bipy is bipyridine and naph is 2-hydroxy-1-naphthaldehyde), was synthesized and characterized by X-ray single-crystal structure analysis. The crystal is triclinic, space group P ?with a = 9.245(4), b = 9.962(4), c = 10.809(7) ? a = 84.83(5), b =82.35(4), g = 81.02(4), V = 972.1 ?, C21H15ClCuN2O6 Mr = 490.36, Z = 2, F(000) = 498, Dx = 1.68 g/cm3, m = 13.05 cm-1, R = 0.078, Rw = 0.081 for 2295 observed reflections with I > 3s(I). The copper(II) ion is coordinated by two nitrogen atoms of bipy and two oxygen atoms of naph in the equatorial plane, with an axial perchlorate oxygen-copper(II) bond to copper(II) ion to form square-pyramidal coordination geometry. The coordination environment of copper(II) is similar to the active site of galactose oxidase and this compound may also be considered as the structural model of galactose oxidase.展开更多
Methyl-galactosides were oxidized at room temperature by galactose oxidase in a one-step reaction and afforded methyl-galactoaldehyde in excellent yield and high purity. The resulting galactoaldehyde as a useful inter...Methyl-galactosides were oxidized at room temperature by galactose oxidase in a one-step reaction and afforded methyl-galactoaldehyde in excellent yield and high purity. The resulting galactoaldehyde as a useful intermediate can be directly used in glycopeptide synthesis.展开更多
Copper-radical oxidases(CROs)catalyze the two-electron oxidation of a large number of primary alcohols includ-ing carbohydrates,polyols and benzylic alcohols as well as aldehydes and𝛼-hydroxy-carbonyl compound...Copper-radical oxidases(CROs)catalyze the two-electron oxidation of a large number of primary alcohols includ-ing carbohydrates,polyols and benzylic alcohols as well as aldehydes and𝛼-hydroxy-carbonyl compounds while reducing molecular oxygen to hydrogen peroxide.Initially,CROs like galactose oxidase and glyoxal oxidase were identified only in fungal secretomes.Since the last decade,their representatives have also been identified in some bacteria.CROs are grouped in the AA5 family of“auxiliary activities”in the database of Carbohydrate-Active enzymes.Despite low overall sequence similarity and different substrate specificities,sequence alignments and the solved crystal structures revealed a conserved architecture of the active sites in all CROs,with a mononuclear copper ion coordinated to an axial tyrosine,two histidines,and a cross-linked cysteine-tyrosyl radical cofactor.This unique post-translationally modified protein cofactor has attracted much attention in the past,which resulted in a large number of reports that shed light on key steps of the catalytic cycle and physico-chemical properties of CROs.Thanks to their broad substrate spectrum accompanied by the only need for molecular oxygen for catal-ysis,CROs since recently experience a renaissance and have been applied in various biocatalytic processes.This review provides an overview of the structural features,catalytic mechanism and substrates of CROs,presents an update on the engineering of these enzymes to improve their expression in recombinant hosts and to enhance their activity,and describes their potential fields of biotechnological application.展开更多
基金supported by grants from the Natural Science Foundation of Hubei province (No. 2010CDB08005)the National Natural Science Foundation of China (No. 30730094 and81000409)Special Funds for State Key Development Program for Basic Research of China (973 Program) (No.2011CB504504)
文摘Mitochondrial DNA(mtDNA) common deletion(CD) plays a significant role in aging and age-related diseases.In this study,we used D-galactose(D-gal) to generate an animal model of aging and the involvement and causative mechanisms of mitochondrial damage in such a model were investigated.Twenty 5-week-old male Sprague-Dawley rats were randomly divided into two groups:D-gal group(n=10) and control group(n=10).The quantity of the mtDNA CD in the hippocampus was determined using a TaqMan real-time PCR assay.Transmission electron microscopy was used to observe the mitochondrial ultrastructure in the hippocampus.Western blot was used to detect the protein levels of NADPH oxidase(NOX) and uncoupling protein 2(UCP2).We found that the level of mtDNA CD was significantly higher in the hippocampus of D-gal-induced aging rats than in control rats.In comparison with the control group,the mitochondrial ultrastructure in the hippocampus of D-gal-treated rats was damaged,and the protein levels of NOX and UCP2 were significantly increased in the hippocampus of D-gal-induced aging rats.This study demonstrated that the levels of mtDNA CD and NOX protein expression were significantly increased in the hippocampus of D-gal-induced aging rats.These findings indicate that NOX-dependent reactive oxygen species generation may contribute to D-gal-induced mitochondrial damage.
基金Supported by the National Natural Science Foundation of China (No. 29971017) the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE China.
文摘A mononuclear copper(II) complex, [Cu(bipy)(naph)(ClO4)] (where bipy is bipyridine and naph is 2-hydroxy-1-naphthaldehyde), was synthesized and characterized by X-ray single-crystal structure analysis. The crystal is triclinic, space group P ?with a = 9.245(4), b = 9.962(4), c = 10.809(7) ? a = 84.83(5), b =82.35(4), g = 81.02(4), V = 972.1 ?, C21H15ClCuN2O6 Mr = 490.36, Z = 2, F(000) = 498, Dx = 1.68 g/cm3, m = 13.05 cm-1, R = 0.078, Rw = 0.081 for 2295 observed reflections with I > 3s(I). The copper(II) ion is coordinated by two nitrogen atoms of bipy and two oxygen atoms of naph in the equatorial plane, with an axial perchlorate oxygen-copper(II) bond to copper(II) ion to form square-pyramidal coordination geometry. The coordination environment of copper(II) is similar to the active site of galactose oxidase and this compound may also be considered as the structural model of galactose oxidase.
基金The National Institute of Health Grant GM49056 supported this study
文摘Methyl-galactosides were oxidized at room temperature by galactose oxidase in a one-step reaction and afforded methyl-galactoaldehyde in excellent yield and high purity. The resulting galactoaldehyde as a useful intermediate can be directly used in glycopeptide synthesis.
基金This work was supported by the Ministry of Innovation,Science and Research the state of North Rhine-Westphalia,Germany within the framework of the NRW-Strategieprojekt BioSC(No.313/323-400-00213)together with the“European Regional Development Fund(EFRE)”,Project“Clus-ter Industrial Biotechnology(CLIB)Kompetenzzentrum Biotechnologie(CKB)”(34.EFRE-0300095/1703FI04)Financial support by the Scien-tific and Technological Research Council of Turkey(TUBITAK)2219-International Research Fellowship Programme for Saadet Alpdagtas is gratefully acknowledged.
文摘Copper-radical oxidases(CROs)catalyze the two-electron oxidation of a large number of primary alcohols includ-ing carbohydrates,polyols and benzylic alcohols as well as aldehydes and𝛼-hydroxy-carbonyl compounds while reducing molecular oxygen to hydrogen peroxide.Initially,CROs like galactose oxidase and glyoxal oxidase were identified only in fungal secretomes.Since the last decade,their representatives have also been identified in some bacteria.CROs are grouped in the AA5 family of“auxiliary activities”in the database of Carbohydrate-Active enzymes.Despite low overall sequence similarity and different substrate specificities,sequence alignments and the solved crystal structures revealed a conserved architecture of the active sites in all CROs,with a mononuclear copper ion coordinated to an axial tyrosine,two histidines,and a cross-linked cysteine-tyrosyl radical cofactor.This unique post-translationally modified protein cofactor has attracted much attention in the past,which resulted in a large number of reports that shed light on key steps of the catalytic cycle and physico-chemical properties of CROs.Thanks to their broad substrate spectrum accompanied by the only need for molecular oxygen for catal-ysis,CROs since recently experience a renaissance and have been applied in various biocatalytic processes.This review provides an overview of the structural features,catalytic mechanism and substrates of CROs,presents an update on the engineering of these enzymes to improve their expression in recombinant hosts and to enhance their activity,and describes their potential fields of biotechnological application.
