桶形芋螺毒管蛋白质组双向电泳条件优化

目的：优化双向电泳的条件,建立适用于桶形芋螺毒管蛋白质组分析的双向电泳方法。方法：对毒管蛋白的提取、上样量及SDS-PAGE凝胶浓度等影响因素进行优化。结果：乙酸提取法适宜于毒管蛋白的提取,对于pH3～10、17cm的IPG胶条,当上样量为0.75mg,聚焦70000Vhr,SDS-PAGE凝胶浓度为15%时,可提高双向电泳的分离效果,所得蛋白点清晰、数目达到1003个。结论：采用优化的条件进行双向电泳,能得到分辨率高、重现性好、完整的双向电泳图谱,为后续桶形芋螺毒管蛋白质组学研究打下基础。     

玉米花丝蛋白质组双向电泳条件的优化

以玉米温敏自交不亲和系‘HE97’的花丝为材料,比较了3种不同蛋白质提取方法对双向电泳结果的影响,并对其中的蛋白质上样量、等电聚焦条件及SDS-PAGE凝胶浓度进行了探索与优化。结果表明,与酚提取法和改良的酚提取法相比,采用三氯乙酸/丙酮提取法提取蛋白质操作简便,所得的双向电泳图谱蛋白质点数较多,图谱背景清晰,是一种提取玉米花丝蛋白质的有效方法。优化后的双向电泳技术体系适合于玉米花丝全蛋白质的双向电泳分析。     

灰木相思蛋白质组双向电泳条件的优化

针对灰木相思(Acacia implexa Benth.)蛋白质提取过程中含有大量色素和酚等干扰物质的现象,进行了实验条件的优化,结果显示:选择含较少次生物质量的组培苗为实验材料更易得到清晰的双向电泳图谱,在裂解液中添加硫脲更有利于提高蛋白溶解度,第一向等电聚焦固相pH梯度胶条(24 cm)的最适蛋白上样量为1000μg,表明采用优化后的双向电泳体系提高了灰木相思总蛋白双向电泳的分辨率和重复性,建立起一套适用于灰木相思总蛋白质组分析的双向电泳(2-DE)方法.     

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.     

人血清蛋白质组学方法的比较和优化

目的:对人未做处理的血清以及去除白蛋白和免疫球蛋白G(IgG)血清的蛋白质组学方法进行比较和优化。方法:应用双向电泳(2-DE)方法分离了未做处理的以及去除白蛋白和免疫球蛋白G(IgG)的血清,比较优化了高温变性、水化液成份组成及泡胀方式等影响血清2-DE分离效果的因素,并用质谱分析鉴定未做处理和已处理血清的2-DE谱图中部分差异蛋白点。结果:得到了分辨率和重复性较好的2-DE谱图,未做处理的血清、去除白蛋白及IgG血清的平均蛋白质点分别为(482±18)个和(523±29)个,质谱分析了9个差异蛋白点,鉴定为8种蛋白质,其中7种为功能蛋白质。仅出现在未做处理血清中的蛋白有4种,分别是维生素A结合蛋白、可溶性尿激酶血纤维蛋白溶酶原激活剂受体、蛋白激酶1抗原、血清白蛋白。4种蛋白仅出现在去除白蛋白和IgG的血清中,分别是NADH脱氢酶辅酶β亚基、肌动蛋白结合蛋白M1、T细胞活性受体β链、血小板生长因子C。结论:去除高丰度蛋白可增加一些低丰度蛋白质的检出,但非特异性吸附会导致部分功能蛋白质的丢失。     

黄瓜子叶节的蛋白质组双向电泳条件的优化

对黄瓜离体子叶节的蛋白质双向电泳的条件进行优化的结果表明:黄瓜子叶节蛋白质主要分布在pH4～7范围,用酚抽提法制备蛋白质干粉,第一向等电聚焦固相pH梯度胶条(24 cm)的最适蛋白上样量为1 2001μg,第二向SDS-PAGE采用11.5%的分离胶,可以得到1100多个蛋白点.     

拟南芥蛋白质组研究中双向电泳技术条件的优化

双向电泳技术是蛋白质组学研究中的关键技术,是目前分辨率最高的工具之一.而提高双向电泳图蛋白质点的数目和分辨率,可以提高蛋白质组技术平台的信息完整性.通过对拟南芥双向电泳技术过程中的适当改进,如蛋白质的提取与溶解方法、上样量和聚丙烯酰胺凝胶浓度,加入硫脲,硫代硫酸钠等,对拟南芥双向电泳技术进行了优化,提高了双向电泳图谱的蛋白质点数目与分辨率.     

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.     

红树植物秋茄叶片双向电泳技术体系的建立及优化

对适用于秋茄(Kandelia candel)叶片蛋白质组学研究的双向电泳技术体系进行了优化.结果表明,采用酚抽提法提取的蛋白质浓度较低,约1.7 μg μL-1,SDS-PAGE电泳后几乎无条带;而采用改良TCA -丙酮沉淀法可显著提高提取液中蛋白质的含量,可达12.4 μgμL-1.秋茄叶片蛋白质主要分布在pH4～...     

水稻蛋白质组双向电泳优化流程及方法

双向电泳是分析蛋白质混合物的一种有力手段,已在蛋白质组研究中得到广泛应用。水稻（Oryzasativa）作为重要的粮食作物,对其蛋白质组学研究开展较早。但由于技术复杂,对实验操作要求高,初学的研究者很难在较短的时间内掌握该实验技术。该文介绍了水稻研究中适合多个组织的双向电泳实验方法和优化流程。该优化流程能使新的研究者逐步优化实验条件,更快更好地完成双向电泳实验。同时详细介绍了实验关键环节的操作方法。     

The use of capillary electrophoresis for DNA polymorphism analysis

Capillary electrophoresis has advanced enormously over the last 10 yr as a tool for DNA sequencing, driven by the human and other major genome projects and by the need for rapid electrophoresis-based DNA diagnostic tests. The common need of these analyses is a platform providing very high throughput, high-quality data, and low process costs. These demands have led to capillary electrophoresis machines with multiple capillaries providing highly parallel analyses, to new electrophoresis matrices, to highly sensitive spectrofluorometers, and to brighter, spectrally distinct fluorescent dyes with which to label DNA. Capillary devices have also been engineered onto microchip formats, on which both the amount of sample required for analysis and the speed of analysis are increased by an order of magnitude. This review examines the advances made in capillary and chip-based microdevices and in the different DNA-based assays developed for mutation detection and genotype analysis using capillary electrophoresis. The automation of attendant processes such as for DNA sample preparation, PCR, and analyte purification are also reviewed. Together, these technological developments provide the throughput demanded by the large genome-sequencing projects.     

Evaluation and optimization of IgY spin column technology in the depletion of abundant proteins from human serum

Serum depletion strategies are commonly implemented in order to remove abundant proteins, increasing the number of proteins detected in a biomarker study. The IgY spin columns used in this study bind 12 and 14 primate proteins, respectively. 1‐D SDS‐PAGE and 2‐DE revealed a suboptimal performance of the IgY spin columns. However, modification of the manufacturer's protocol, subjecting samples to two rounds of depletion, improved the number of proteins resolved by 2‐DE. With alteration of the manufacturer protocol, the Seppro^® IgY14 spin column can produce depleted serum with an increased number of spots resolved by 2‐DE compared to untreated serum.     

Elastic image registration of 2-D gels for differential and repeatability studies

One of the main applications of electrophoretic 2-D gels is the analysis of differential responses between different conditions. For this reason, specific spots are present in one of the images, but not in the other. In some other occasions, the same experiment is repeated between 2 and 12 times in order to increase statistical significance. In both situations, one of the major difficulties of these analysis is that 2-D gels are affected by spatial distortions due to run-time differences and dye-front deformations, resulting in images that are significantly dissimilar not only because of their content, but also because of their geometry. In this technical brief, we show how to use free, state-of-the-art image registration and fusion algorithms developed by us for solving the problem of comparing differential expression profiles, or computing an "average" image from a series of virtually identical gels.     

Capillary chromatography-coupled mass spectrometry with column switching for rapid identification of proteins from 2-dimensional electrophoresis gels

An improved capillary liquid chromatography procedure, incorporating column switching in combination with mass spectrometry, is reported. The dual column system allows for rapid inject-to-inject cycle times to improve the speed of protein identification for proteomics applications. Full gradient elution of peptides from either of the two C18 columns can be achieved in less than 17 min while maintaining sufficient resolution for the peptides to be detected and fragmented by the mass spectrometer for protein identification. Importantly, the use of two columns for subsequent injections is reproducible and without carry-over. The limit of detection for the system is between 25 and 50 fmol per injection. This fully automated system is capable of analyzing and identifying proteins from an entire 96-well plate in about 27 h.     

小菜蛾血淋巴蛋白质双向电泳技术体系的建立及优化

采用不同方法对小菜蛾Plutella xylostella(L.)血淋巴进行双向电泳研究,建立了一套适用于小菜蛾血淋巴蛋白质组分析的双向电泳体系。从样品处理方案、等电聚焦时间、染色方法等因素对小菜蛾双向电泳结果的影响进行了分析和优化。结果表明,TCA/丙酮沉淀法提取蛋白损失少,图谱均匀清晰,分辨率和重复性更高。不同长度胶条的最佳上样量不同,胶条长度为7、17、24cm时,最佳上样量依次为20～50μg、50～300μg、100～500μg,而聚焦时间则分别以24000、50000、65000vhr为宜。第二向聚丙烯酰胺凝胶的浓度以12%为宜,电泳后蛋白点呈均匀分布。银染的灵敏度明显高于考马斯亮蓝染色,可以检测出更多的蛋白点,但考马斯亮蓝染色在后续蛋白点质谱鉴定中具有优势。     

The state of the art in the analysis of two-dimensional gel electrophoresis images

Software-based image analysis is a crucial step in the biological interpretation of two-dimensional gel electrophoresis experiments. Recent significant advances in image processing methods combined with powerful computing hardware have enabled the routine analysis of large experiments. We cover the process starting with the imaging of 2-D gels, quantitation of spots, creation of expression profiles to statistical expression analysis followed by the presentation of results. Challenges for analysis software as well as good practices are highlighted. We emphasize image warping and related methods that are able to overcome the difficulties that are due to varying migration positions of spots between gels. Spot detection, quantitation, normalization, and the creation of expression profiles are described in detail. The recent development of consensus spot patterns and complete expression profiles enables one to take full advantage of statistical methods for expression analysis that are well established for the analysis of DNA microarray experiments. We close with an overview of visualization and presentation methods (proteome maps) and current challenges in the field. An erratum to this article can be found at     

Yeast plasma membrane ghosts. An analysis of proteins by two-dimensional gel electrophoresis

We have examined yeast cell ghost preparations to assess their value in obtaining plasma membrane proteins. Ghosts prepared by two methods involving stabilization of spheroplast envelopes had similar protein patterns by two-dimensional gel electrophoresis, and approximately 200 proteins were resolved. Spheroplasts were lactoperoxidase iodinated, and recovery of label in ghost preparations was greater than 60%. Spheroplasts appeared to be impermeable to the lactoperoxidase reagents as judged by an examination of two-dimensional gel electrophoretic patterns of ghost proteins that had been iodinated in spheroplasts or in unsealed ghosts. Spheroplasts were also impermeable to pronase proteases. Surface iodination and surface proteolysis allowed us to identify exposed ghost proteins; the major ghost glycoprotein was exposed in spheroplasts.Two-dimensional patterns of ghost proteins were not heavily contaminated (?25% of all proteins) by proteins present in soluble or promitochondrial fractions, and estimates of surface label and total cell protein recovery suggested that the ghost fraction represents a cell envelope enrichment of 8–10 fold over whole cells.Resolution of ghost proteins by two-dimensional gel electrophoresis appears to be a powerful aid toward identifying membrane proteins.     

Comparison of different depletion strategies for improved resolution in proteomic analysis of human serum samples

Serum proteins may often serve as indicators of disease and is a rich source for biomarker discovery. However, the large dynamic range of proteins in serum makes the analysis very challenging because high-abundant proteins tend to mask those of lower abundance. A prefractionation step, such as depletion of a few high-abundant proteins before protein profiling, can assist in the discovery and detection of less abundant proteins that may prove to be informative biomarkers. In the present study, five different depletion columns were investigated considering efficiency, specificity, and reproducibility. Our research included quantitative determination of total protein, albumin, and immunoglobulin G (IgG) concentrations, one- and two-dimensional gels and mass spectrometric analysis of the serum samples before and after the depletion step. Our results showed that all five depletion columns tested removed albumin and IgG with high efficiency. We found that based on reproducibility and binding specificity, the Multiple Affinity Removal Column that removed a total of six high-abundant proteins (albumin, IgG, antitrypsin, IgA, transferring, and haptoglobin) offered the most promising depletion approach. Among the disposable (single-use) products, the ProteoExtract Albumin/IgG Removal kit displayed the best results. Depleted serum from the Multiple Affinity Removal column was further evaluated by 2-D gel electrophoresis (2-DE) analysis, and the results indicated increased resolution and improved intensity of low-abundant proteins in a reproducible fashion. Our study provides a comprehensive investigation of commercially available depletion columns and will be of high importance for future proteomic studies on serum samples.     

Proteomic analysis of nicotine-associated protein expression in the striatum of repeated nicotine-treated rats

Through the proteomic analysis using 2-dimensional electrophoresis, the nicotine addiction-associated proteins were extensively screened in the striatum of rat brains. The nicotine addiction was developed by repeated nicotine injection (0.4mg/kg s.c.), twice daily for 7 days, followed by one challenge injection after a 3 day withdrawal period, and then confirmed by observing a 2.3-fold increase in locomoter activity. The 3 up- and 4 down-regulated proteins were selected and identified to be zinc-finger binding protein-89 (ZBP-89), 2'3'-cyclic nucleotide 3'-phosphodiesterase 1, deoxyribonuclease 1-like 3 (DNase1l3), tandem pore domain halothane inhibited K(+) channel (THIK-2), brain-specific hyaluronan-binding protein (BRAL-1), death effector domain-containing DNA binding protein (DEDD), and brain-derived neurotrophic factor (BDNF) by mass spectrophotometric fingerprinting. Among them, the expression patterns of ZEB-89, DNase1l3, THIK-2, DEDD, and BDNF mRNAs were found to be coincident with those of cognate proteins, by using RT-PCR analysis. These proteins could be suggested as drug targets to develop a new therapy for nicotine-associated diseases, as well as the clues to understand the mechanism of nicotine.     

Hierarchical grid transformation for image warping in the analysis of two-dimensional electrophoresis gels

Two-dimensional electrophoresis is a widely used method for separating a large number of proteins from complex protein mixtures and for revealing differential patterns of protein expressions. In the computer-assisted proteome research, the comparison of protein separation profiles involves several heuristic steps, ranging from protein spot detection to matching of unknown spots. An important prerequisite for efficient protein spot matching is the image warping step, where the geometric relationship between the gel profiles is modeled on the basis of a given set of known corresponding spots, so-called landmarks, and the locations of unknown spots are predicted using the optimized model. Traditionally, polynomial functions together with least squares optimization has been used, even though this approach is known to be incapable of modeling all the complex distortions inherent in electrophoretic data. To satisfy the need of more flexible gel distortion correction, a hierarchical grid transformation method with stochastic optimization is presented. The method provides an adaptive multiresolution model between the gels, and good correction performance in the practical cross-validation tests suggests that automatic warping of gel images could be based on this approach. We believe that the proposed model also has significance in the ultimate comparison of corresponding protein spots since the matching process should benefit from the closeness of the true spot pairs.