槟榔叶片总蛋白质提取及双向电泳条件初探

采用3种提取植物组织蛋白的方法(TCA/丙酮沉淀法、E-TCA法、酚法)提取槟榔叶片总蛋白,在蛋白产量,一维和二维电泳图谱等方面对3种方法的提取效果进行比较.结果表明,TCA/丙酮沉淀法效果较好,是槟榔叶片总蛋白提取的可选方法,同时优化了双向电泳的条件和上样量.     

油菜种子蛋白质提取方法研究

通过对比改进的Tris-HCl法、酚提取-甲醇/醋酸铵沉淀法、TCA/丙酮沉淀法和DTT/丙酮法4种方法提取油菜未成熟种子蛋白质,以期找到合适的蛋白质提取方法。结果表明,TCA/丙酮沉淀法和DTT/丙酮法所得蛋白质沉淀较多,颜色亮白,效果较好。进一步通过定量分析及双向电泳图谱的比较分析表明,TCA/丙酮沉淀法在2-DE图谱上蛋白质点较多,分布均匀,图像清晰,而DTT/丙酮法相对于本实验中TCA/丙酮法检测到较少的蛋白质点外,2-DE图谱上有明显的纵条纹。因此TCA/丙酮沉淀法为提取油菜种子中蛋白质的最优方法。     

茶树总蛋白质提取方法及双向电泳体系的建立

为探索适用于茶树叶片蛋白质组学研究的双向电泳技术体系(2-DE),比较三氯乙酸(TCA)/丙酮沉淀法和改良酚抽法2种不同总蛋白质提取方法、不同蛋白上样量对2-DE的影响。结果表明:改良酚抽法更适合茶树总蛋白质的提取;采用1.5 mg的蛋白质上样量,最终可获得蛋白质点较多、背景清晰、分辨率较高的双向电泳图谱,为进一步深入开展茶树蛋白质组学的研究奠定了基础。     

龙眼胚性愈伤组织γ-ECS基因的克隆及表达分析

为探讨红麻细胞质雄性不育形成的分子遗传机理，以红麻细胞质不育系L23A和保持系L23B开花期叶片为材料，对其红麻蛋白质双向电泳体系进行研究，比较TCA/丙酮和酚抽提法提取红麻叶片总蛋白，同时优化上样量和样品制备方法，建立了红麻蛋白质的双向电泳技术体系和凝胶成像染色法，利用PDquest软件分析双向电泳凝胶的相关差异蛋白。结果表明：（1）TCA/丙酮法比酚抽提法更适合于ISO-DALT电泳系统；（2）TCA/丙酮提取的红麻叶片粗蛋白平均产量为31.67 mg/g，是酚抽提法的1.77倍, 但裂解效率为160 mg/g，是酚抽提法的36％；（3）每根胶条最佳上样量为300 μg；（4）考马斯亮蓝G-250比R-250以及银染色法效果更佳，在17 cm×17 cm的凝胶上平均可获得708个蛋白质点。本研究建立的红麻细胞质雄性不育系与保持系总蛋白提取方法及双向电泳体系，可为揭示红麻雄性不育分子机理奠定基础。     

大豆叶片蛋白响应干旱胁迫的双向电泳分析

大豆是我国重要的农作物之一,蛋白质组学技术是解析植物响应逆境胁迫的重要工具之一。为进一步推进对响应干旱胁迫的大豆叶片蛋白的鉴定工作,以大豆幼苗的叶片为研究对象,用甘露醇溶液模拟干旱胁迫,处理24 h后提取叶片蛋白粉进行双向电泳分离和图谱差异分析。结果表明:采取三氯醋酸(TCA)-丙酮沉淀法提取的叶片蛋白进行双向电泳分离能够得到稳定清晰的双向电泳蛋白图谱。采取PD-Quest软件对干旱胁迫下的大豆叶片蛋白表达图谱进行差异分析,共检测和匹配425个大豆叶片蛋白点,其中差异表达的蛋白点有101个,60个表达量上调,41个表达量下调。本研究结果表明有一部分大豆叶片蛋白响应了干旱胁迫。     

茶树雌蕊总蛋白质双向电泳分离体系的建立

为建立一套适合茶树雌蕊总蛋白质分离的双向电泳体系,对茶树雌蕊总蛋白的提取方法、SDS-PAGE凝胶浓度、聚焦条件和IPG胶条pH范围等进行了比较优化。结果表明,TCA/丙酮-clean up kit法提取总蛋白,用17 cm pH 5~8 IPG胶条,13%SDS-聚丙烯酰胺凝胶进行分离,用考马斯亮蓝R250染色,可以获得清晰、分辨率高、重复性好的双向电泳图谱,共检测到约1200个蛋白点,主要分布在pH 5~8,相对分子量14~117 kD范围内,碱性蛋白得到有效分离,可以满足茶树雌蕊的蛋白组学分析和研究。     

茶树雌蕊总蛋白质双向电泳分离体系的建立

为建立一套适合茶树雌蕊总蛋白质分离的双向电泳体系,对茶树雌蕊总蛋白的提取方法、SDS-PAGE凝胶浓度、聚焦条件和IPG胶条pH范围等进行了比较优化。结果表明,TCA/丙酮-clean up kit法提取总蛋白,用17 cm pH 5~8 IPG胶条,13%SDS-聚丙烯酰胺凝胶进行分离,用考马斯亮蓝R250染色,可以获得清晰、分辨率高、重复性好的双向电泳图谱,共检测到约1 200个蛋白点,主要分布在pH 5~8,相对分子量14~117 kD范围内,碱性蛋白得到有效分离,可以满足茶树雌蕊的蛋白组学分析和研究。     

冬小麦叶片抗旱蛋白质组双向电泳技术体系的优化

为给小麦抗旱蛋白质组学研究提供技术支撑,以两个抗旱性不同的冬小麦品种周麦18和晋麦47三叶期幼苗为材料,比较分析了PEG胁迫处理后两种不同蛋白质提取方法TCA/丙酮法和磷酸钠缓冲液研磨法对IEF/SDSPAGE双向电泳的影响,并在IPG胶条pH范围、蛋白质上样量和SDSPAGE胶浓度等方面进行了探索与优化。结果表明,采用TCA/丙酮法提取叶片全蛋白,选用17 cm、pH 4~7的IPG线性胶条,在上样量为150 μg·胶条_-1,以及12%SDSPAGE胶浓度下进行双向凝胶电泳,蛋白质能够更好地被分离,2DE图谱上可分辨出约400个蛋白点。利用该体系比较了PEG胁迫后两个品种双向电泳图谱的差异,周麦18有9个蛋白点存在差异,其中5个下调表达,4个上调表达(3个新诱导表达);晋麦47有5个蛋白点存在差异,均上调表达(1个新诱导表达)。     

橡胶树胶乳全蛋白的提取及双向电泳分析

以橡胶树无性系RRIM600为材料，采用TCA(三氯乙酸)-丙酮沉淀法提取胶乳全蛋白，17 cm pH 5～8固相pH梯度预制干胶条和快速银染法对提取的蛋白进行分离和染色，所得到的电泳图谱背景清晰，横条纹和竖条纹少，且蛋白点数量多。通过本研究获得了高分辨率的胶乳全蛋白双向电泳(2-DE)图谱的方法，为进一步开展橡胶树胶乳全蛋白质组学研究奠定了基础。     

对科研院所科技开发工作的思考

以玉米(Zea mays L.)中糯二号为材料，采用改进的TCA(三氯乙酸)-丙酮沉淀法提取玉米叶片的蛋白质，并从蛋白样品纯化和上样量2个方面对玉米叶片双向电泳体系进行优化。结果表明：蛋白纯化后且上样量为150 μg时，能获得背景清晰，横条纹、竖条纹少，蛋白点多的双向电泳图谱。这为开展玉米中糯二号的蛋白质组学研究提供技术支持。     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).