发菜蛋白质组双向电泳技术的建立及优化

为建立适用于发菜(Nostoc flagelliforme)蛋白质组研究的双向电泳技术,对发菜蛋白质的提取、裂解、上样量、IEF及SDS-PAGE电泳等关键步骤进行了优化,结果显示:发菜蛋白质主要分布在pH 4～7范围内,采用改良TCA法可提高提取液中蛋白质的含量和双向电泳图谱的分辨率,裂解液含60 mmol/L DTT,24 cm IPG胶条上样量1.5 mg时不仅提高了蛋白质的溶解性,而且改善了双向电泳的分离效果,得到近800个蛋白点,且蛋白点清晰,图谱分辨率较好.采用优化后的双向电泳体系提高了发菜蛋白质双向电泳的分辨率和重复性,建立起一套适用于发菜蛋白质组分析的双向电泳方法.     

水牛睾丸曲精细管蛋白质组双向电泳方法的建立及优化

建立并优化了沼泽型水牛睾丸曲精细管蛋白质分离的双向电泳体系,为后续水牛睾丸曲精细管蛋白质表达谱的鉴定和研究奠定基础。比较不同IPG胶条(线性与非线性)、胶条pH范围和蛋白质上样量这三个参数对双向电泳结果的影响。结果显示,采用上样量350μg的曲精细管总蛋白、24 cm且pH值4～7的线性IPG胶条能够更好地分离水牛睾丸曲精细管蛋白质,获得质量较好且分辨率较高的双向电泳图谱,得到大约486个蛋白点。双向凝胶电泳技术能够对水牛睾丸曲精细管蛋白质进行有效分离,并通过对双向电泳体系的优化可获得蛋白质点清晰且分辨率更高的双向电泳图谱。     

适用于生菜叶片蛋白质双向电泳方法的建立及初步应用

以生菜(Lactuca sativa)叶片为研究材料,参考拟南芥和水稻的双向电泳方法,分析了等点聚焦时间和染色方法等影响双向电泳的关键因素,建立适合生菜叶片总蛋白质分离的双向电泳方法:采用三氯乙酸-丙酮沉淀法进行总蛋白质提取,用24cm固相pH梯度等电聚焦8000V×8h结合12%的SDS-PAGE进行双向电泳分离,银染法和考马斯亮蓝染色法染色都获得了较好的结果.应用Image-Master-Elite软件对考马斯亮蓝染色法染色的图谱进行分析表明:每张凝胶上都检测到超过1000个的蛋白质,不同凝胶之间蛋白质的匹配律达到98%,具有较高的分辨率和重复性.初步分析了生菜叶片蛋白质的等电点、分子量的分布情况,发现生菜叶片蛋白质的等电点以5.0～5.5之间最多而分子量主要集中在20～60kD之间.     

北方常绿阔叶木本植物叶片蛋白质双向电泳技术体系优化

以北海道黄杨为模型植物,比较了3种不同叶片蛋白质提取方法,并优化了双向电泳各个环节技术体系,进一步用5种北方常绿阔叶木本植物进行验证,以建立适合北方常绿阔叶木本植物蛋白质分析的双向电泳技术体系.结果表明:(1)采用改进的酚/SDS方法提取叶片蛋白质,用添加硫脲和磺基三甲基胺乙内脂3～10的裂解液裂解蛋白,使用24 cm固相pH梯度胶条,考马斯亮蓝染色蛋白上样量800 μg,最多可得到分辨率高、重复性好的蛋白点912个;银染色蛋白上样量110 μg,最多可得到分辨率高、重复性好的蛋白点587个.(2)用优化的技术体系对5种北方常绿阔叶木本植物进行分析,结果显示5种植物叶片蛋白质2-DE图谱均背景清晰,分辨率好,重复性较好(重复组的相似系数平均为68.60%);5 种植物平均可得到约371个清晰可重复的蛋白点,其中大叶黄杨、扶芳藤、北海道黄杨、金心黄杨和小叶黄杨的2-DE重复组蛋白点数目分别为346、407、353、352和399个.表明本研究优化的蛋白质提取以及双向电泳技术体系适用于对北方常绿阔叶木本植物叶片的比较蛋白质组学分析.     

3种不同油桐种仁蛋白质提取方法比较研究

一种有效的蛋白质提取方法是蛋白质双向电泳成功分离的关键。油桐种仁可以用来制取工业用桐油,但其中富含大量的能干扰蛋白质提取的物质,并能影响双向电泳图谱的分辨率。本文中对油桐种仁蛋白质采用丙酮提取（方法A）、苯酚抽提（方法B）以及丙酮—苯酚结合提取（方法C）,并通过蛋白质双向电泳技术对这3种方法的提取效果进行比较研究。结果显示：采用方法C所提取的蛋白质样品,其蛋白浓度高达到8.1 μg·μL^-1;并且该方法对油桐种仁中的高分子量、低分子量蛋白均有较强的提取能力;此外,其蛋白样品经过双向电泳所得到的蛋白质点和图谱分辨率也较其余两种方法好。     

一种提高固定pH梯度（IPG）凝胶双向电泳的重复性、分辨率和通量的方法

在蛋白质组学研究中 ,双向聚丙烯酰胺凝胶电泳是现行蛋白质分离的最重要的方法之一。实验发展了一种提高固定pH梯度 (IPG)凝胶双向电泳的重复性、分辨率和通量的方法 :在一块SDS 聚丙烯酰胺凝胶上同时进行多块固定pH梯度(IPG)凝胶 (Multi stripsononeSDSgel,MSOG)电泳。用此方法比较了人肝癌细胞、不同生长状态的人肝癌细胞、3T3细胞的蛋白质以及同一个样品在不同大小的第二向凝胶系统 (大型和中型凝胶 )的双向电泳图谱。结果表明 ,同一样品在 13cmIPGStrip双向电泳可分离 2 0 0 0以上蛋白质点且图谱蛋白质点的匹配率可超过 95 %以上。同时又可以最大程度地降低凝胶背景对蛋白质点比较分析的干扰 ,从而提高了双向电泳分离蛋白质的分辨率和通量。这些优点都有助于差异蛋白质组学特别是细胞器差异蛋白质组学研究的自动化。     

一种改良的植物蛋白质双向电泳方法

O'Farrell等介绍的蛋白质双向电泳技术,将两个独立的参数(等电点和分子量)结合起来,使蛋白质的电泳分辨率有了极大提高,特别是对复杂系统中的蛋白质分析,提供了一种有效手段。但是这种电泳系统一般只适用于动物和微生物,植物组织中由于含     

植物叶片蛋白质双向电泳技术的改进与优化

通过对传统的双向电泳方法进行改进与优化,得到了一种适合于分析植物叶片蛋白质的双向电泳新方法。用改进后的方法对水稻不同时期成熟叶片蛋白质进行双向电泳分离,结果显示其稳定性和重复性好,分辨率较高,经考马斯亮蓝染色后可分辨出３００多个蛋白质（肽）点。它们的等电点和分子量主要分布于ｐ＊４．１－８．２和１０－１００ｋＤａ之间,本还就实验过程中出现的一些技术问题进行了讨论。     

不同上样方式对蛋白质组双向电泳图谱质量的影响比较

蛋白质组技术难点之一是如何获取尽可能多的细胞或组织的蛋白信息.双向电泳蛋白斑点数目直接反映了实验蛋白质组信息的完整性.除样品制备外,蛋白上样方式对双向电泳图谱的质量和完整性有直接的影响.实验论文从以下3个方面考察不同的蛋白上样方式对双向电泳图谱的影响;即：水化上样与杯上样;一次上样与重复上样;以及酸性端加样与碱性端上样.实验结果发现;蛋白上样量较大时,杯上样方式的图谱斑点数目较水化上样方式明显增多;样品蛋白浓度较高时,稀释多次上样明显优于一次性浓缩蛋白上样;蛋白裂解液(MCF7乳腺癌细胞)在酸性端加样对偏碱性蛋白的分离未发现明显优势.相反,在等电聚焦伏小时(Vh) 足够的前提下,碱性端加样对偏碱性端蛋白反而有利,表现为斑点数目较多,而且等电点方向拖尾减轻.实验结果对提高双向电泳的质量以及相关蛋白质组信息的完整性提供了有益的技术参考.     

胆管癌胆汁蛋白质样品制备和双向电泳条件的优化

采用合适的裂解液和沉淀方法,提取胆管癌胆汁中的蛋白质,获得分辨率高、重复性好的蛋白质双向电泳图谱.通过不同裂解液和蛋白质沉淀方法提取胆汁蛋白的效果比较,设计了不同的样品制备方法,并且对双向电泳(2-DE)的条件进行优化.结果显示,试验确定了适合胆管癌胆汁的裂解液配方(LSⅣ),丙酮沉淀的蛋白分布完整,沉淀效率相对较高.高伏时、长时间的等电聚焦可以获得高分辨率、重复性好的蛋白质双向电泳图谱.因此,本方法可以应用到胆管癌胆汁蛋白的提取,也可以对其他体液蛋白质样品的制备和双向电泳提供借鉴.     

Applications of affinity chromatography in proteomics

Affinity chromatography is a powerful protein separation method that is based on the specific interaction between immobilized ligands and target proteins. Peptides can also be separated effectively by affinity chromatography through the use of peptide-specific ligands. Both two-dimensional electrophoresis (2-DE)- and non-2-DE-based proteomic approaches benefit from the application of affinity chromatography. Before protein separation by 2-DE, affinity separation is used primarily for preconcentration and pretreatment of samples. Those applications entail the removal of one protein or a class of proteins that might interfere with 2-DE resolution, the concentration of low-abundance proteins to enable them to be visualized in the gel, and the classification of total protein into two or more groups for further separation by gel electrophoresis. Non-2-DE-based approaches have extensively employed affinity chromatography to reduce the complexity of protein and peptide mixtures. Prior to mass spectrometry (MS), preconcentration and capture of specific proteins or peptides to enhance sensitivity can be accomplished by using affinity adsorption. Affinity purification of protein complexes followed by identification of proteins by MS serves as a powerful tool for generating a map of protein-protein interactions and cellular locations of complexes. Affinity chromatography of peptide mixtures, coupled with mass spectrometry, provides a tool for the study of protein posttranslational modification (PTM) sites and quantitative proteomics. Quantitation of proteomes is possible via the use of isotope-coded affinity tags and isolation of proteolytic peptides by affinity chromatography. An emerging area of proteomics technology development is miniaturization. Affinity chromatography is becoming more widely used for exploring PTM and protein-protein interactions, especially with a view toward developing new general tag systems and strategies of chemical derivatization on peptides for affinity selection. More applications of affinity-based purification can be expected, including increasing the resolution in 2-DE, improving the sensitivity of MS quantification, and incorporating purification as part of multidimensional liquid chromatography experiments.     

小麦根蛋白提取与双向电泳方法的优化与应用

为了建立一套适合小麦根蛋白质组分析的双向电泳系统（2-DE）,得到更加清晰的电泳图谱,本研究以小麦幼苗根系为材料,对根蛋白的提取方法、上样量等进行了优化。研究发现,上样量为1200μg时,Trizol抽提法提取的蛋白能够获得图像清晰、分辨率高、重复性好的双向电泳图谱,基本满足小麦根系蛋白质组学的分析和研究。     

The effect of DTT in protein preparations for proteomic analysis: Removal of a highly abundant plant enzyme, ribulose bisphosphate carboxylase/oxygenase

Rubisco is a major photosynthetic plant enzyme in the chloroplasts, catalyzing a photosynthetic reaction through carboxylation and oxygenation in the leaves. Despite its biological importance, its high abundance causes difficulties in the proper separation of protein mixtures during 2-dimensional gel electrophoresis (2-DE). Here, we resolved those plant soluble proteins by efficiently removing Rubisco. This resulted in a high quality and resolution of 2-DE gels. Rubisco removal was achieved through aggregation in the presence of a high DTT concentration, which subsequently increased the visualization of less abundant proteins and reduced horizontal streaking. This simple method may provide a means for finding more biologically important protein targets via plant proteomics.     

水牛精子蛋白质组双向电泳体系的建立和优化

建立和优化一种适合水牛精子蛋白质组学研究的双向电泳技术。以水牛精子为研究对象,比较两种不同配方的裂解液,以及不同上样量对其2-DE图谱质量的影响。结果显示,以7 mol/L尿素、2 mol/L硫脲、4%CHAPS、1%DTT、0.5%Cocktail of protease inhibitors为裂解液,24 cm胶条上样量200μg时,可获得较好的精子总蛋白质2-DE图谱。运用ImageMaster 2-Dplatinum分析软件检测出约500个蛋白质点,蛋白质大部分分布在等电点5-7之间,分子量范围约40-90 kD。     

Optimization of the first dimension for separation by two-dimensional gel electrophoresis of basic proteins from human brain tissue

A major cause of poor resolution in the alkaline pH range of two-dimensional electrophoresis (2-DE) gels is unsatisfactory separation of basic proteins in the first dimension. We have compared methods for the separation of basic proteins in the isoelectric focusing dimension of human brain proteins. The combined use of anodic cup-loading and the hydroxyethyldisulphide containing solution (DeStreak) produced better resolution in both analytical and micropreparative protein loaded 2-DE gels than the other methods investigated.     

Improvements in two-dimensional gel electrophoresis by utilizing a low cost "in-house" neutral pH sodium dodecyl sulfate-polyacrylamide gel electrophoresis system

Two-dimensional gel electrophoresis (2-DE) is widely used for initial protein separation in proteomics. Commercial products using neutral pH sodium dodecyl sulfate-polyacrylamide gel electrophoresis ((SDS-PAGE)/(Bis (2-hydroxyethyl) imino-tris (hydroxymethyl) methane-HCl, or Bis-Tris)) have greatly improved this technique, but cost and limited sizes restrict their applications. An "in-house" system is presented, resulting in better resolution, separation, and new spot visualization and improved resolution when compared to Tris-HCl gels. Their utility is demonstrated using albumin-depleted serum samples, rabbit heart left ventricle, and human immunodeficiency virus type 1 (HIV-1).     

Current two-dimensional electrophoresis technology for proteomics

Two-dimensional gel electrophoresis (2-DE) with immobilized pH gradients (IPGs) combined with protein identification by mass spectrometry (MS) is currently the workhorse for proteomics. In spite of promising alternative or complementary technologies (e.g. multidimensional protein identification technology, stable isotope labelling, protein or antibody arrays) that have emerged recently, 2-DE is currently the only technique that can be routinely applied for parallel quantitative expression profiling of large sets of complex protein mixtures such as whole cell lysates. 2-DE enables the separaration of complex mixtures of proteins according to isoelectric point (pI), molecular mass (M_r), solubility, and relative abundance. Furthermore, it delivers a map of intact proteins, which reflects changes in protein expression level, isoforms or post-translational modifications. This is in contrast to liquid chromatography-tandem mass spectrometry based methods, which perform analysis on peptides, where M_r and pI information is lost, and where stable isotope labelling is required for quantitative analysis. Today's 2-DE technology with IPGs (Görg et al., Electrophoresis 2000, 21, 1037–1053), has overcome the former limitations of carrier ampholyte based 2-DE (O'Farrell, J. Biol. Chem. 1975, 250, 4007–4021) with respect to reproducibility, handling, resolution, and separation of very acidic and/or basic proteins. The development of IPGs between pH 2.5–12 has enabled the analysis of very alkaline proteins and the construction of the corresponding databases. Narrow-overlapping IPGs provide increased resolution (δpI = 0.001) and, in combination with prefractionation methods, the detection of low abundance proteins. Depending on the gel size and pH gradient used, 2-DE can resolve more than 5000 proteins simultaneously (˜2000 proteins routinely), and detect and quantify < 1 ng of protein per spot. In this article we describe the current 2-DE/MS workflow including the following topics: sample preparation, protein solubilization, and prefractionation; protein separation by 2-DE with IPGs; protein detection and quantitation; computer assisted analysis of 2-DE patterns; protein identification and characterization by MS; two-dimensional protein databases.     

箭毒木种子蛋白质样品制备及双向电泳改良方法

建立箭毒木（Antiaris toxicaria）种子总蛋白的提取方法,以及可以对其蛋白质组进行分析的双向电泳条件。通过各种条件的优化与组合,建立了以TCA-丙酮为基础的Tris—HCl提取法提取总蛋白,第1向电泳为固相pH梯度等电聚焦,第2向电泳为垂直平板SDS-PAGE的双向电泳体系。通过对样品制备、样品溶解、等电聚焦电泳、SDS-聚丙烯酰胺凝胶电泳以及染色方法等关键步骤进行分析,获得了满意的双向电泳图谱。在探索适合箭毒木种子蛋白质组学研究双向电泳方法中,比较了三氯乙酸-丙酮沉淀法、和Tris—HCl法,以及对双向电泳过程中的关键步骤的改良,认为Tris—HCl法为最适方法,所得图谱背景清晰,蛋白质信息量最大,为箭毒木属植物的差异蛋白质组学的后续研究打下了坚实的基础。     

Evaluation of protein extraction methods for Vitis vinifera leaf and root proteome analysis by two-dimensional electrophoresis

An efficient protein extraction method is crucial to ensure successful separation by two-dimensional electrophoresis(2-DE)for recalcitrant plant species, in particular for grapevine(Vitis vinifera L.). Trichloroacetic acid-acetone(TCA-acetone)and phenol extraction methods were evaluated for proteome analysis of leaves and roots from the Tunisian cultivar 'Razegui'. The phenol-based protocol proved to give a higher protein yield,a greater spot resolution, and a minimal streaking on 2-DE gels for both leaf and root tissues compared with the TCA-based protocol. Furthermore, the highest numbers of detected proteins on 2-DE gels were observed using the phenol extraction from leaves and roots as compared with TCA-acetone extraction.