豆壳过氧化物酶的序列联配、二级结构预测及疏水性分析

利用生物大分子数据库和软件技术对豆壳过氧化物酶 (Soybeanhullperoxidase ,SHP ,EC 1 .1 1 .1 .7)进行了序列联配、二级结构预测及疏水性分析 ,通过与其它来源过氧化物酶的比较研究 ,分析了结构保守性与功能域的关系 ,从分子水平探讨了过氧化物酶活性位点结构特征。     

一种基于纳米胶团自组装结构人工过氧化物酶

用十二烷基硫酸钠与血红素和组氨酸通过自组装的方式构建了一种纳米结构人工过氧化物酶(AP)。利用紫外可见光分光光度仪测量AP结构酶促反应过程,观察到了过氧化物酶活性在pH 8.0,50 mmol/L Na2HPO4-NaH2PO4缓冲溶液时达到最大。该AP的米氏常数Km、催化速率以及催化效率分别为5.5μmol/L、0.6 s-1、0.011μM-1.s-1,其催化效率为天然辣根过氧化物酶的15%。     

无金属卟啉置换辣根过氧化物酶辅基研究

不同结构的卟啉插入去辅基辣根过氧化物酶(apo-HRP)所得重构酶具有类过氧化物酶的催化活性.采用紫外分光光度法和荧光光度法对这些重构酶进行研究.结果表明TPyP-apo-HRP比其他卟啉类插入重构蛋白具有的类过氧化物酶催化活性高.     

辣根过氧化物酶处理邻苯二酚废水的研究

研究了用辣根过氧化物酶催化处理邻苯二酚废水的效果.结果表明,用辣根过氧化物酶可以有效地去除邻苯二酚.其最佳处理条件为:pH值4.4、过氧化氢与邻苯二酚的摩尔比约2∶1、反应时间30 min,适当增加酶用量可以明显缩短反应时间.     

新型自组装纳米胶团人工过氧化物酶研究

十二烷基肌氨酸钠与天然细胞色素c通过自组装方式构建了一种新型纳米胶团结构人工过氧化物酶(Artificial Peroxidase,AP)。采用紫外可见光分光光度计对AP酶促反应过程进行研究。表明AP在较宽的pH范围具有活性,并在pH 5.0,100 mmol/L磷酸盐缓冲液中达到最大。该AP的米氏常数Km、催化速率kcat以及催化效率分别为1.70μmol/L、0.11 s-1、0.065μM-1s-1,催化效率为天然辣根过氧化物酶的90.2%。     

三相法分离番薯过氧化物酶

采用三相法(TPP)分离纯化番薯过氧化物酶(SPP),以番薯过氧化物酶的酶活回收率和纯化倍数为优化目标,分别利用单因素法和响应面分析法对其影响因素进行考察。建立了最佳提取条件:以叔丁醇作溶剂、硫酸铵饱和度为66%、粗提物与叔丁醇体积比为1. 0∶1. 13、温度为26℃、pH=5. 0,在最优提取条件下,其酶活回收率和纯化倍数分别达133. 5%和3. 5。SDS-PAGE电泳分析结果显示SPP酶蛋白主要为一条带,其分子质量约为40 kDa左右。三相法操作简便、耗时短、成本低,此外分离过程增强了SPP酶与底物的亲和力,提高了酶活回收率,有利于工业化应用。     

辣根过氧化物酶降解苯酚废水催化特性研究

采用辣根过氧化物酶催化降解苯酚,研究了辣根过氧化物酶浓度、pH值、反应温度对苯酚去除率的影响。结果表明,辣根过氧化物酶生物催化体系对苯酚有良好的降解效果。当温度为30℃,pH值为6时,在苯酚、H2O2、辣根过氧化物酶浓度分别为1 mmol/L,1.2 mmol/L,0.5μg/mL条件下,反应25 min,可以获得70%左右的苯酚去除率。利用双倒数作图法测定了不同酶浓度的催化动力学参数,动力学参数Kcat,Kcat/Km表明,苯酚的去除率和催化反应速率随着酶浓度的增加而增大;辣根过氧化物酶的催化效率与催化体系中酶和底物浓度有关,过高的底物浓度会降低酶的催化效率。     

共固定化葡萄糖氧化酶研究进展

葡萄糖氧化酶广泛应用于分析检测、生物传感、食品工业等领域.酶的共固定化可以在同一反应体系中因偶联反应而提高催化效果.本文综述了近年来葡萄糖氧化酶与氯过氧化物酶、辣根过氧化物酶、脂肪酶等其他酶共固定化研究进展,展望了葡萄糖氧化酶共固化载体的设计及其应用.     

Fe_3O_4纳米酶的制备、表征及类酶活性初探

过氧化物酶的性质在生物系统中有很多重要的作用,研究发现很多纳米材料都有类过氧化物酶的催化活性,且纳米材料成本低、易制备。本实验利用添加表面活性剂十二烷基磺酸钠(SDS)修饰技术的超声波共沉淀法,成功制备出平均粒径在20 nm左右的Fe_3O_4纳米酶,该纳米酶活力值为7.28×108ΔA/min·g(mL),采用X射线粉末衍射仪(XRD)、傅立叶转换红外线光谱仪(FT-IR)、扫描电镜等方法对Fe_3O_4纳米酶进行表征,经XRD的表征确定最佳配比为n(FeCl_2):n(FeCl_3)=1∶1,该Fe_3O_4纳米酶可以有效催化H-O键氧化3,3,5,5—四甲基联苯胺(TMB),利用发生的显色反应体现出良好的过氧化物模拟酶催化活性,研究了反应条件对Fe_3O_4纳米酶形貌和结构的影响,证实了Fe_3O_4纳米酶为结晶完整、常温下表现出良好的过氧化物模拟酶性质的晶体。     

石墨电极上甲基纤维素膜固载辣根过氧化物酶的直接电化学

用甲基纤维素（MC）将辣根过氧化物酶（HRP）固定在热裂解石墨电极表面,制备了HRP-MC膜修饰电极.包埋在甲基纤维素膜中的辣根过氧化物酶可以与电极直接传递电子.在pH 7.0的磷酸盐缓冲溶液中可得到一对可逆的辣根过氧化物酶辅基血红素Fe（Ⅲ）/Fe（Ⅱ）电对氧化还原峰,式电势为-0.349 V（vs SCE）.其式电势随溶液pH值增加而负移且成线性关系,直线斜率为-40.0 mV/pH,说明辣根过氧化物酶的电子传递过程伴随有质子的转移.并研究了HRP-MC膜修饰电极对H2O2、NO的电催化性质.     

Production of horse radish peroxidase by plant cell culture

Calluses were induced from the stem and the root tissues of horse radish plantlets. Cell aggregate selections were carried out on them to obtain a cell line with higher peroxidase activity, and the isozyme patterns of the peroxidases from the cultured cells and their utility values as a clinical diagnostic reagent were investigated. The repetition of the cell aggregate selection resulted in increases in peroxidase activities in each generation of selection; about eleven fold in the 13th generation of selection from the stem tissues and about nine fold in the 13th generation from the root tissues. One of the cell lines (N5K6-S), originally derived from the stem tissues, after selectin showed a tenfold increase in peroxidase activity within two weeks of culture in a liquid medium. The value as a clinical diagnostic reagent of peroxidases extracted from the N5K6-S cells was estimated to be equivalent to those already commercially available for the same purpose. There were significant differences in the isoenzyme patterns of the peroxidases from root tissues and those from cultured cells. From these results, the possibility of commercial production of peroxidase utilizing plant tissue and cell culture techniques was discussed.     

DyP-Type Peroxidases: Recent Advances and Perspectives

In this review, we chart the major milestones in the research progress on the DyP-type peroxidase family over the past decade. Though mainly distributed among bacteria and fungi, this family actually exhibits more widespread diversity. Advanced tertiary structural analyses have revealed common and different features among members of this family. Notably, the catalytic cycle for the peroxidase activity of DyP-type peroxidases appears to be different from that of other ubiquitous heme peroxidases. DyP-type peroxidases have also been reported to possess activities in addition to peroxidase function, including hydrolase or oxidase activity. They also show various cellular distributions, functioning not only inside cells but also outside of cells. Some are also cargo proteins of encapsulin. Unique, noteworthy functions include a key role in life-cycle switching in Streptomyces and the operation of an iron transport system in Staphylococcus aureus, Bacillus subtilis and Escherichia coli. We also present several probable physiological roles of DyP-type peroxidases that reflect the widespread distribution and function of these enzymes. Lignin degradation is the most common function attributed to DyP-type peroxidases, but their activity is not high compared with that of standard lignin-degrading enzymes. From an environmental standpoint, degradation of natural antifungal anthraquinone compounds is a specific focus of DyP-type peroxidase research. Considered in its totality, the DyP-type peroxidase family offers a rich source of diverse and attractive materials for research scientists.     

黄孢原毛平革菌的降解机制及其应用

黄孢原毛平革菌产生的胞外酶由木素过氧化酶、锰过氧化酶和己二醛氧化酶等组成，对染料废水有降解功能．并具有传统处理方法所无法比拟的优点。本文对黄孢原毛平革菌的降解机制和在工业上的应用做一简要综述。有16篇参考文献。     

过氧化物酶的应用研究进展

过氧化物酶在过氧化物氧化底物的过程中起着重要的作用,广泛应用于生物技术领域.过氧化物酶的热不稳定性是抑制其应用的主要因素,现正设计成新的催化剂形式来克服其稳定性问题,增加其热稳定系数.     

Fifteen years of Raman spectroscopy of engineered heme containing peroxidases: what have we learned?

Spectroscopic techniques have been fundamental to the comprehension of peroxidase function under physiological conditions. This Account examines the contribution to our understanding of heme peroxidases provided by electronic and resonance Raman spectroscopies in conjunction with site-directed mutagenesis. The results obtained over 15 years with several heme peroxidases and selected mutants have provided important insights into the influence exerted by the protein in the vicinity of the active site via key amino acids on the functionality and stability of the enzymes. Moreover, resonance Raman spectroscopy has revealed that a common feature of heme peroxidases is the presence of an extensive network of H-bonds coupling the distal and proximal sides, which has a profound influence on the heme ligation, affecting both the fifth and the sixth coordination sites.     

Modelling of the lignin peroxidase LIII of Phlebia radiata: use of a sequence template generated from a 3-D structure

A model of the lignin peroxidase LIII of Phlebia radiata wasconstructed on the basis of the structure of cytochrome c peroxidase(CCP). Because of the low percentage of amino acid identitybetween the CCP and the lignin peroxidase LIII of Phlebia radiata,alignment of the sequences was based on the generation of atemplate from a knowledge of the 3-D structure of CCP and consensussequences of lignin peroxidases. This approach gave an alignmentin which all the insertions in the lignin peroxidase were placedat loop regions of CCP, with a 21.1% identity for these twoproteins. The model was constructed using this alignment andthe computer program COMPOSER, which assembles the model asa series of rigid fragments derived from CCP and other proteins.Manual intervention was required for some of the longer loopregions. The -helices forming the structural framework, andespecially the haem environment of CCP, are conserved in theLIII model and the core is close packed without holes. A possiblesite of the substrate oxidation at the haem edge of LIII isdiscussed.     

Hypoxia-Responsive Class III Peroxidases in Maize Roots: Soluble and Membrane-Bound Isoenzymes

Flooding induces low-oxygen environments (hypoxia or anoxia) that lead to energy disruption and an imbalance of reactive oxygen species (ROS) production and scavenging enzymes in plants. The influence of hypoxia on roots of hydroponically grown maize (Zea mays L.) plants was investigated. Gene expression (RNA Seq and RT-qPCR) and proteome (LC–MS/MS and 2D-PAGE) analyses were used to determine the alterations in soluble and membrane-bound class III peroxidases under hypoxia. Gel-free peroxidase analyses of plasma membrane-bound proteins showed an increased abundance of ZmPrx03, ZmPrx24, ZmPrx81, and ZmPr85 in stressed samples. Furthermore, RT-qPCR analyses of the corresponding peroxidase genes revealed an increased expression. These peroxidases could be separated with 2D-PAGE and identified by mass spectrometry. An increased abundance of ZmPrx03 and ZmPrx85 was determined. Further peroxidases were identified in detergent-insoluble membranes. Co-regulation with a respiratory burst oxidase homolog (Rboh) and key enzymes of the phenylpropanoid pathway indicates a function of the peroxidases in membrane protection, aerenchyma formation, and cell wall remodeling under hypoxia. This hypothesis was supported by the following: (i) an elevated level of hydrogen peroxide and aerenchyma formation; (ii) an increased guaiacol peroxidase activity in membrane fractions of stressed samples, whereas a decrease was observed in soluble fractions; and (iii) alterations in lignified cells, cellulose, and suberin in root cross-sections.     

Characterization of Class V DyP-Type Peroxidase SaDyP1 from Streptomyces avermitilis and Evaluation of SaDyPs Expression in Mycelium

DyP-type peroxidases are a family of heme peroxidases named for their ability to degrade persistent anthraquinone dyes. DyP-type peroxidases are subclassified into three classes: classes P, I and V. Based on its genome sequence, Streptomyces avermitilis, eubacteria, has two genes presumed to encode class V DyP-type peroxidases and two class I genes. We have previously shown that ectopically expressed SaDyP2, a member of class V, indeed has the characteristics of a DyP-type peroxidase. In this study, we analyzed SaDyP1, a member of the same class V as SaDyP2. SaDyP1 showed high amino acid sequence identity to SaDyP2, retaining a conserved GXXDG motif and catalytic aspartate. SaDyP1 degraded anthraquinone dyes, which are specific substrates of DyP-type peroxidases but not azo dyes. In addition to such substrate specificity, SaDyP1 showed other features of DyP-type peroxidases, such as low optimal pH. Furthermore, immunoblotting using an anti-SaDyP2 polyclonal antibody revealed that SaDyP1 and/or SaDyP2 is expressed in mycelia of wild-type S. avermitilis.     

过氧化物酶应用的生物技术进展

介绍了过氧化物酶可以催化的四种反应类型 :氧化去氢反应、氧化卤化反应、双氧水歧化反应、氧传递反应。综述了过氧化物酶在有机合成等反应中的应用前景。认为氯过氧化物酶是一种应用最广的过氧化物酶 ,在催化有机反应时 ,具有更高的手性选择性和酶稳定性