H20：浸种对水稻种子萌发生长及其过氧化物酶同工酶、醋酶同工酶的影响。

适当浓度的H,O,溶液浸种能促进水稻种子萌发生长和提高发芽率,特别是对贮存两年的杂交稻 种子的促进作用尤为明显,其中0.5% H,O,浸种效果最佳。分析水稻种子萌发过程中的过氧化物酶 同工酶和va酶同工酶,结果表明,浸种三天后,处理组的过氧化物酶同工酶和醋酶同工酶酶谱都比对照 组的多4条酶带,且处理组的两种同工酶带染色均比对照组的深。这说明,H,O,浸种后某些同工酶提 前出现,种子的生理生化代谢比较活袄,这与种子萌发生长加快和发芽率提高是一致的。     

空间条件对草地早熟禾植株过氧化物同工酶和酯酶同工酶的影响

将草地早熟禾(Poa pratensis L.)巴润(baron)干种子分别进行蒸馏水和硼酸处理后利用返回式卫星搭载,以未搭载干种子作为对照.对不同处理植株过氧化物同工酶(POD)和酯酶同工酶(EST)酶谱进行分析.结果表明,空间条件处理引起部分草地早熟禾植株POD和EST的差异,在酶带位置、数量、强弱等方面与对照相比出现了一定的变化,说明空间条件作用后草地早熟禾种子后代植株产生了一定变异.     

萝卜贮藏期过氧化物酶活性及同工酶谱研究

为了研究萝卜贮藏期过氧化物酶的活性变化和作用 ,利用愈创木酚法和聚丙烯酰胺凝胶电泳方法检测在贮藏期萝卜过氧化物酶的活性及同工酶谱 ,实验结果表明 :不同品种的萝卜在不同贮藏时期其过氧化物酶活性及同工酶谱存在差异。贮藏时间越长过氧化物酶活性越高 ,同工酶谱酶带增多。萝卜色素含量越高 ,POD活性也越高 ,因此 ,在萝卜贮藏期有可能过氧化物酶在清除细胞内H2 O2 方面起主要作用     

模拟微重力条件下几种植物的过氧化物酶同工酶谱分析

对模拟微重力条件下的人参果、马铃著和草莓处理后进行了过氧化物酮同工酶谱分析实验。结果表明,在模拟微重力条件下过氧化物同工酶的活性明显增强。     

甘蔗过氧化物酶同工酶分析

以３０个甘蔗品种为材料,用垂直平板聚丙烯酰胺凝胶电泳,分析甘蔗不同生长时期过氧化物酶同工酶。个别品种还进行同一品种在不同种植地区、同一植株不同叶位的同工酶酶谱比较,结果表明,不同品种的酶谱其酶带分布有明显的区别,但同一品种在不同种植地区、不同生长时期、不同植株、同一植株不同叶位其酶带分布无差异,体现了同工酶作为品种标记具有多态性及稳定性。用单一酶系即可准确、方便地鉴定甘蔗品种。     

甘蔗过氧化物酶同工酶分析

以30个甘蔗品种为材料,用垂直平板聚丙烯酰胺凝胶电泳,分析甘蔗不同生长时期过氧化物酶同工酶。个别品种还进行同一品种在不同种植地区、同一植株不同叶位的同工酶酶谱比较,结果表明,不同品种的酶谱其酶带分布有明显的区别,但同一品种在不同种植地区、不同生长时期、不同植抹、同一植株不同叶位其酶带分布无差异,体现了同工酶作为品种标记具有多态性及稳定性。用单一酶系即可准确、方便地鉴定甘蔗品种。     

模拟微重力条件下几种植物的过氧化物酶同工酶谱分析

对模拟微重力条件下的人参果、马铃薯和草莓处理后进行了过氧化物酶同工酶谱分析实验。结果表明 ,在模拟微重力条件下过氧化物同工酶的活性明显增强     

天麻3种变型过氧化物酶的同工酶研究

采用聚丙烯酰胺凝胶电泳（PAGE）对天麻3种变型的过氧化物酶（POD）的同工酶进行了研究。结果表明,天麻3种变型的过氧化物酶的同工酶活性不同,酶谱条带数在5～7条之间,且具有特征谱带。其中乌天麻和红天麻的酶谱条带数相同,两者的酶谱条带数均多于绿天麻;绿天麻、乌天麻和红天麻的酶谱条数依次分别为5条、7条和7条;其中基本酶带有5条,Rf值分别为0．06、0．24、0．83,0．89、0．98;乌天麻与红天麻的相似度指数为0．86,说明这两个种亲缘关系近;乌天麻与绿天麻的相似度指数为0．71,反映它们之间的亲缘关系相对较远。     

芒果属植物过氧化物酶同工酶的研究

采用聚丙烯酰胺凝胶电泳法,测定了芒果属１７个种群近缘植物过氧化物酶同工酶,并根据酶谱分布及酶谱特征,结合不同的表现形式,分析了属内种间的亲缘关系。结果表明,异（同）地种间、不同器官酶谱数目、酶含量、迁移率（Ｒｆ）、酶活性及分布特征均有不同程度的差异,可以作为芒果属种间亲缘关系的生化遗传指标。     

温度对六种外来杂草过氧化物酶同工酶谱的影响

应用聚丙烯酰胺垂直板凝胶电泳 ,比较了加拿大一枝黄花 (Solidagocanadensis)、小飞蓬 (Conyzacanadensis)、野塘蒿 (Conyzabonarinsis)、钻形紫菀 (Astersublatus)、一年蓬 (Erigeronannuus)和马缨丹 (Lan tanacamara)等 6种外来杂草在 3 8、2 5、5°C处理 60h后的过氧化物酶同工酶谱差异 ,分析了酶谱差异与对温度适应的关系。结果表明 ,温度变化对一年蓬、小飞蓬、钻形紫菀过氧化物酶同工酶谱的影响相对较小 ,野塘蒿通过增加酶带、调整同工酶的组成来适应温度的变化 ,反映出这 4种杂草对温度变化具有较强的适应能力 ;加拿大一枝黄花表现出对高温的适应能力较弱 ,对低温适应性较强 ,马缨丹对温度变化表现出相反的适应特点。     

Purification,characterization and catalytic activity of anionic zucchini peroxidase

The isolation and purification, by preparative electrofocusing, of the major anionic (ZPOA) and cationic (ZPOC) isoenzymes, collected from young zucchini squash, are reported. The M _r and sugar content are similar to those found previously for the major isoenzymes from the ripe fruits and in the range commonly observed for plant peroxidases. The amount of the two cationic enzymes was very low compared with that of anionic ZPOA. The anionic enzyme has been characterized by electronic, circular dichroism, proton NMR and electron paramagnetic resonance spectroscopy. The spectra are qualitatively similar to those of the corresponding anionic horseradish peroxidase (HRPA) derivatives, with minor differences attributable to the particular protein environment around the heme. The kinetics of the enzymatic oxidation of a series of phenols by H₂O₂ have been studied. ZPOA shows a parallel behavior to HRPA, but it is systematically more active than HRPA, indicating that the zucchini enzymes have a marked tendency to carry out oxidation of this type of compounds.     

Relative shifts in mobility in anionic peroxidase isoenzymes between stem base and apex of flax genotrophs

Anionic peroxidase isoenzymes, separated on acrylamide gels, were examined in two flax genotrophs and in their reciprocal F₂ hybrids. Isoenzyme 1 exhibited a significant difference in R_m between stem base and apex and there was a gradient of decreasing R_m and activity between base and apex. Isoenzyme 2 displayed only the activity gradient. The parents differed significantly in the R_m's and activities of isoenzymes 1 and 2, and the F₂'s showed complete dominance of the L parent for R_m, with activities being approximately intermediate.     

Role of glutathione peroxidase in protecting mammalian spermatozoa from loss of motility caused by spontaneous lipid peroxidation

Mouse and human spermatozoa, but not rabbit spermatozoa, have long been known to be sensitive to loss of motility induced by exogenous H₂O₂. Recent work has shown that loss of sperm motility in these species correlates with the extent of spontaneous lipid peroxidation. In this study, the effect of H₂O₂ on this reaction in sperm of the three species was investi gated. The rate of spontaneous lipid peroxidation in mouse and human sperm is markedly enhanced in the presence of 1-5 mM H₂O₂, while the rate in rabbit sperm is unaffected by H₂O₂. The enhancement of lipid peroxidation, the rate of reaction of H₂O₂ with the cells, the activity of sperm glutathione peroxidase, and the endogenous glutathione content are highest in mouse sperm, intermediate in human sperm, and very low in rabbit sperm. Inac tivation of glutathione peroxidase occurs in the presence of H₂O₂ due to complete conver sion of endogenous glutathione to GSSG: No GSH is available as electron donor substrate to the peroxidase. Inactivation of glutathione peroxidase by the inhibitor mercaptosucci nate has the same effect on rate of lipid peroxidation and loss of motility in mouse and human sperm as does H₂O₂. This implies that H₂O₂ by itself at 1-5 mM is not intrinsically toxic to the cells. With merceptosuccinate, the endogenous glutathione is present as GSH in mouse and human sperm, indicating that the redox state of intracellular glutathione by itself plays little role in protecting the cell against spontaneous lipid peroxidation. Mouse and human sperm also have high rates of superoxide production. We conclude that the key intermediate in spontaneous lipid peroxidation is lipid hydroperoxide generated by a chain reaction initiated by and utilizing superoxide. Removal of this hydroperoxide by gluta thione peroxidase protects these sperm against peroxidation; inactivation of the peroxidase allows lipid hydroperoxide to increase and so increases the peroxidation rate. Rabbit sperm have low rates of superoxide reaction due to high activity of their superoxide dismutase; lack of endogenous glutathione and low peroxidase activity does not affect their rate or lipid peroxidation. As a result, these sperm are not affected by either H₂O₂ or mercapto-succinate. These results lead us to postulate a mechanism for spontaneous lipid peroxida tion in mammalian sperm which involves reaction of lipid hydroperoxide and O₂ as the rate-determining step.     

Systematic implications of the peroxidase isoenzymes in the Xanthium strumarium complexes

Starch-slab gel electrophoresis showed two patterns of peroxidase isoenzymes in the polymorphic taxon. Xanthium strumarium L. The “strumarium” morphological complex (X. strumarium, in the sense of Millspaugh and Sherff), the putative indigenous plants of the Old World, contained a different pattern from that shown by putative introductions from the New World. Experimental F₁ hybrids between “strumarium” and other complexes, “italicum-pennsylvanicum”, “chinense”, “oviforme” and “cavanillesii”, had the peroxidase pattern of the American plants. These peroxidase isoenzyme patterns were not influenced by the environmental growing conditions, but, along with partial genetic incompatibility, support the taxonomic separation of X. strumarium from other taxa of section Euxanthium.     

Persistence of differences between peroxidase isoenzymes of flax genotrophs in tissue culture

Anionic peroxidase isoenzymes from seedling root, hypocotyl and cotyledon regions of the large (L) and small (S) flax genotrophs were separated on acrylamide gels. Tissue cultures were initiated from each of these regions of the seedlings, and maintained for a 200-day period with six transfers. The differences in electrophoretic mobility of the peroxidase isoenzymes between L and S noted in seedlings, and also in main stems of adult plants, were still present in the tissue cultures.     

Kinetics of fenugreek peroxidase isoenzymes

Peroxidase from fenugreek seedlings was separated into 6 isoenzymes; 4 on CM-cellulose and 2 on DEAE-cellulose. The kinetics of these peroxidase isoenzymes with regard to o-dianisidine and catechol are described.     

Methylglyoxal inhibition of cytosolic ascorbate peroxidase from Nicotiana tabacum

Methylglyoxal (MG) is one of the aldehydes accumulated in plants under environmental stress. Cytosolic ascorbate peroxidase (cAPX) plays a key role in the protection of cells from oxidative damage by scavenging reactive oxygen species in higher plants. A cDNA encoding cAPX, named NtcAPX, was isolated from Nicotiana tabacum. We characterized recombinant NtcAPX (rNtcAPX) as a fusion protein with glutathione S‐transferase to investigate the effects of MG on APX. NtcAPX consists of 250 amino acids and has a deduced molecular mass of 27.5 kDa. The rNtcAPX showed a higher APX activity. MG treatments resulted in a reduction of APX activity and modifications of amino groups in rNtcAPX with increasing K_m for ascorbate. On the contrary, neither NaCl nor cadmium reduced the activity of APX. The present study suggests that inhibition of APX is in part due to the modification of amino acids by MG. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:315–321, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21423     

Partial characterization of peroxidase isoenzymes from rust-affected wheat leaves

Four anodic peroxidase isoenzymes from wheat leaves were purified by column chromatography and their kinetic behavior with common substrates were examined. One isoenzyme is more active in wheat resistant to stem rust fungi and differed from the others in carbohydrate content and also by a specific activity 2–4-fold higher with non-physiological electron donors. As a substrate, eugenol exhibited kinetic behavior different from p-phenylenediamine, guaiacol or o-dianisidine with all isoenzymes. All four isoenzymes showed similar pH and temperature optima and kinetic behavior and apparent K_m values for both H₂O₂ and non-physiological electron donors.     

大豆过氧化物酶－过氧化氢－碘化钾体系杀菌作用

【目的】研究豆壳过氧化物酶(SBP)-H2O2-KI三元体系杀菌作用及其可能的杀菌机制。【方法】以细菌生长的浊度(OD600)为指标检测SBP-H2O2-KI体系的抑菌作用;以活细胞计数(CFU)为指标检测SBP-H2O2-KI体系的杀菌作用;以最低抑菌浓度(MIC)为指标检测亚致死剂量的SBP-H2O2-KI体系作用下连续传代细菌的敏感性变化;以物理和化学方法检测SBP-H2O2-KI体系中活性氧基团等功能基团的生成与否,以期解释SBP-H2O2-KI体系的杀菌机制。【结果】SBP-H2O2-KI体系对多种细菌有高效、快速杀菌作用,作用时间仅为几分钟。在亚致死剂量浓度下连续培养的细菌悬液对体系的耐受能力(MIC)没有显著性变化,从中也不能分离到抗性/耐性突变株。物理和化学方法检测结果表明SBP-H2O2-KI反应过程中无羟基自由基产生;化学方法检测结果表明SBP-H2O2-KI反应过程中无超氧阴离子自由基产生;而有单线态氧和单质碘的产生。【结论】根据实验结果可以推测:SBP-H2O2-KI体系的杀菌力可能主要来源于单线态氧和碘的活性中间态,而不是羟基自由基和超氧阴离子。此外,SBP-H2O2-KI体系所具备的高效、快速的杀菌作用,以及细菌对其不易产生抗性的特点,预示此体系在医疗以及植保等方面有广泛的应用前景。