铜锌超氧化物歧化酶(Cu2Zn2SOD)在汞电极上的吸附研究

金属氧化还原蛋白质的电化学行为作为生物电化学领域中一个重要的研究内容,受到了广泛的关注犤1～3犦,生物体系一些重要的反应均与基本电荷运动有关,如生物催化、神经传导、光合作用以及呼吸作用等均涉及到一些重要氧化还原蛋白质的氧化还原过程。利用电化学的基本原理和实验方法,不但能在生命体系和有机组织的整体水平上,更主要是能在分子和细胞水平上研究氧化还原蛋白质体系中的电子转移以及氧化态转化的化学本质和规律。铜锌超氧化物歧化酶(Cu2Zn2SOD)是一个二聚体,由两个等同的亚单位组成,每一个亚单位含有咪唑桥联的铜?和锌?离子,催…     

Absolute quantification of superoxide dismutase in cytosol and mitochondria of mice hepatic cells exposed to mercury by a novel metallomic approach

In the last years, the development of new methods for analyzing accurate and precise individual metalloproteins is of increasing importance, since numerous metalloproteins are excellent biomarkers of oxidative stress and diseases. In that way, methods based on the use of post column isotopic dilution analysis (IDA) or enriched protein standards are required to obtain a sufficient degree of accuracy, precision and high limits of detection. This paper reports the identification and absolute quantification of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) in cytosol and mitochondria from mice hepatic cells using a innovative column switching analytical approach. The method consisted of orthogonal chromatographic systems coupled to inductively coupling plasma-mass spectrometry equipped with a octopole reaction systems (ICP-ORS-MS) and UV detectors: size exclusion fractionation (SEC) of the cytosolic and mitochondrial extracts followed by online anion exchange chromatographic (AEC) separation of Cu/Zn containing species. After purification, Cu,Zn-SOD was identified after tryptic digestion by molecular mass spectrometry (MS). The MS/MS spectrum of a doubly charged peptide was used to obtain the sequence of the protein using the MASCOT searching engine. This optimized methodology reduces the time of analysis and avoids the use of sample preconcentration and clean-up procedures, such as cut-off centrifuged filters, solid phase extraction (SPE), precipitation procedures, off-line fractions insolates, etc. In this sense, the method is robust, reliable and fast with typical chromatographic run time less than 20 min. Precision in terms of relative standard deviation (n = 5) is of 3–5% and detection limits is 0.21 ng Cu g⁻¹.     

铅污染对条斑紫菜的毒害影响

研究分析了不同浓度Pb2+对条斑紫菜植物体叶绿素a含量,POD、SOD活性,MDA含量,总抗氧化能力以及可溶性蛋白质含量的影响.结果表明,随着Pb2+浓度的增加,叶绿素a含量,POD、SOD活性,MDA的含量,总抗氧化能力,可溶性蛋白质及均呈先升后降趋势.条斑紫菜对Pb2+具有较高的耐性.     

不同南瓜品种嫁接黄瓜耐冷性指标的研究

对 9个南瓜品种与黄瓜嫁接后幼苗的生理生化指标进行了试验研究。结果表明 :嫁接苗的POD、SOD活性提高 ,嫁接使黄瓜抵抗低温能力增强。初步认为日本杂种南瓜、6 7号、长媳为耐冷性较好的黄瓜砧木     

The synthesis,crystal structures and SOD activities of a new ligand (Lse) and Co(Lse)2(SCN)2 complex [Lse = selenium ether bis‐(N‐1‐methyl‐ benzotriazole)]

A new ligand containing selenium, Se (CH₂‐N‐Btrzole)₂ (L^se) (Btrzole = benzotriazole) and its cobalt(II) complex, Co(L^se)₂(SCN)₂, have been synthesized and the molecular structures of the title compounds have been determined by X‐ray techniques. The L^se is a meso‐configuration with a symmetric plane through the Se center, the intermolecular weak interactions of Se? Se, Se? N and π? π stacking between benzotriazole rings to extend the molecular structure to two‐dimensional network configuration. In the Co(II) complex, the metal center is in a six‐coordinated octahedral environment. Two Co(II) atoms are linked by two ligands to form a 20‐membered macrocycle; the adjacent macrocycles are linked by coordinated bond of Co? N_bentrozole to extend an infinite double strained chain. The SOD activity of the ligand and Co(II) complex have been studied by using the pyrogallol autoxidation method; thermal properties and luminescent properties of Co(II) complex have been tested, and the details of those properties have been discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

过氧化氢酶对超氧化物歧化酶清除O2^.作用的影响

采用ＮＢＴ（氮兰四唑）光还原法测定过氧化氢酶（ＣＡＴ）存在下对超氧化物歧化酶清除Ｏ２＾．自由基的影响。     

Interpretation of the cytostatic properties of sodium morpholyldithiocarbamate,a chelating agent

Summary The antioxidant properties of sodium morpholyldithiocarbamate (MorDTC) were studied in order to contribute to the interpretation of its antitumor activity and synergetic effect overcis-platinum.MorDTC inhibits pyrogallol autooxidation better than vitamin C but does not dismutate the superoxide radical generated by the xanthine — xanthine oxidase system. Nevertheless, the complexes formedin situ betweenMorDTC and Mn(II), Co(II), Ni(II), and Cu(II) do dismutate the superoxide radical with a SOD-like activity (SOD=superoxide dismutase), expressed in terms of IC₅₀ values within the range of 3.2 to 62 µM. The highest activity corresponds to Mn(II) and Cu(II) complexes. The possible inhibitory action ofMorDTC on erythrocyte SOD was also studiedin vitro; however, the results were negative. Therefore,MorDTC should dismulate the superoxide radical after chelating metals without inhibiting SOD, the enzyme playing this rolein vivo.

---

Interpretation der cytostatischen Eigenschaften von Natriummorpholyldithiocarbamat, einem komplexbildenden Reagens

Zusammenfassung Die antioxidativen Eigenschaften von Natriummorpholyldithiocarbamat (MorDTC) wurden im Hinblick auf seine Wirkung gegen Tumore und seinem synergistischen Effekt im Zusammenhang mitcis-Platin untersucht.MorDTC hemmt die Autoxidation von Pyrogallol besser als Vitamin C, greift aber das vom System Xanthin-Xanthinoxidase gebildete Superoxidradikal nicht an. Dieses wird jedoch von demin situ ausMorDTC und Mn(II), Co(II), Ni(II) und Cu(II) gebildeten Komplexen mit einer SOD-vergleichbaren Aktivität umgesetzt (SOD=Superoxiddismutase; IC₅₀ im Bereich von 3.2 bis 62 µM). Die höchste Aktivität wurde für Mn(II)- und Cu(II)-Komplexe gefunden. Die hemmende Wirkung vonMorDTC auf erythrocytische SOD wurdein vitro untersucht. Die Ergebnisse waren negativ.MorDTC ist daher nach der Komplexierung mit Metallen in der Lage, das Superoxidradikal anzugreifen, ohne SOD, das Enzym, das Enzym, das diese Aufgabein vivo übernimmt, zu hemmen.