双向电泳过程中的常见问题及解决方法

[目的]研究蛋白质组双向电泳中出现的问题及解决方法。[方法]培养野生型K12菌株Escherichia coli MG1655，分离其蛋白质样品并进行SDS-PAGE聚丙烯酰胺凝胶电泳。[结果]双向电泳中存在蛋白质点没有出现或很少，纵纹与横纹现象严重等问题。[结论]该研究为以后开展双向电泳试验打下了基础。     

苗期夜间低温处理对番茄叶片蔗糖代谢的影响

[目的]探讨夜间低温处理对番茄叶片蔗糖代谢的影响。[方法]以夜温15℃为对照,设夜温6℃（18：00—6：00）为处理,处理7d后测定番茄叶片糖和淀粉含量及蔗糖代谢相关酶活性。[结果]夜间低温处理增加了叶片中的果糖、葡萄糖、蔗糖、总糖和淀粉的含量,果糖和葡萄糖含量与对照相比差异不显著,蔗糖、总糖和淀粉含量与对照相比差异达极显著水平;夜间低温处理增加了叶片中酸性转化酶（AI）和中性转化酶（NI）活性,降低了蔗糖合成酶（SS）和蔗糖磷酸合成酶（SPS）活性。[结论]夜间低温导致番茄叶片中光合产物积累,对光合作用产生反馈抑制。     

Identification of novel haze-active beer proteins by proteome analysis

Colloidal haze reduces beer quality considerably. Four haze samples were analyzed by two-dimensional gel electrophoresis (2DE) in order to identify haze-active proteins. Several protein spots were observed in all of the four haze samples. Using mass spectrometry analysis followed by a database search identified these spots as barley dimeric alpha-amylase inhibitor (BDAI-1), CMb component of tetrameric alpha-amylase inhibitor (CMb) and trypsin inhibitor CMe precursor (CMe). These proteins were considered to be haze-active. Since haze-active proteins are adsorbed by silica gel in the beer filtration process, we eluted proteins adsorbed onto silica gel (PAS) and identified their species. These major PAS were identified as protein Z4, protein Z7 and trypsin/amylase inhibitor pUP13 (TAI), rather than BDAI-1, CMb and CMe. Furthermore, we analyzed proline compositions in the beer proteins, PAS and the haze proteins. Consequently, we found that the proline compositions of PAS were higher (ca. 20 mol%) than those in the beer proteins (ca. 10 mol%), although those of the haze-active proteins such as BDAI-1, CMb and CMe were 6.6–8.7 mol%. Our results suggest that BDAI-1, CMb and CMe are not predominant haze-active proteins, but growth factors of beer colloidal haze.     

Proteomic analysis of wheat recombinant inbred lines: Variations in prolamin and dough rheology

To investigate the impact of the 1BL.1RS translocation on dough strength and to understand how 1BL.1RS genotypes may overcome the loss of Glu-B3 and Gli-B1, proteomic profiles of 16 doubled haploid (DH) lines of similar glutenin composition but of different strength, as measured by Chopin's alveograph, were compared. The results showed that 32 spots, mainly prolamins, were differentially expressed and that five others were specific to high-strength DH lines. The identification and quantification of the prolamin fractions on the two-dimensional (2D) electrophoresis gels demonstrated that the high-molecular weight glutenin sub-unit (HMW-GS) were up-regulated by 25% in 1BL.1RS DH lines, even though the corresponding genes were not located on the missing 1BS chromosome. The γ-gliadins were also up-regulated (by 36%) in such lines to counterbalance, to some extent, the loss of LMW-GS of Glu-B3. The polymeric prolamin fractions also accumulated in high-tenacity lines and decreased in high-extensibility lines confirming the role of the inter-chain disulfide bonds in resistance to deformation. In contrast, the monomeric fraction of α-gliadin favored extensibility and decreased tenacity by increasing the accumulation (+12%) of α-gliadins in high-extensibility lines; the Gli-A1 allele of the parent Toronit was found to be more abundant when compared to the Gli-A1 allele of parent 211.12014.     

Changes of expressive proteome of renal tissues in chronic intermittent hypoxic rats

AIM: To obtain the two-dimensional gel electrophoresis maps of renal tissue proteins for identifying the differentially expressed proteins in the chronic intermittent hypoxic rats. METHODS: The rat model of chronic intermittent hypoxia was established. The rats lived in the normoxia environment were used for control. The proteins in the renal tissues underwent two-dimensiona1 gel electrophoresis with immobiline pH gradient isoelectric focusing as the first and vertical SDS-PAGE as the second dimension. Analysis of 2-DE maps was performed to determine the differential expression of proteins between the two groups by the software of ImageMaster 2D Platinum V5.0, in which 4 protein spots expressed differentially were picked up for further identification by MALDI-TOF-MS. RESULTS: Matched and compared with those in control group, 112 protein spots were determined in chronic intermittent hypoxia group. By MALDI-TOF-MS, 4 protein spots with the highest differentially expressive levels were identified as ATP synthase delta subunit mitochondrial precursor, hexokinase, catechol O-methyltransferase and apurinic/apyrimidinic endonudease/redox factor-1. The functions of these identified proteins are involved in cellular energy metabolism, apoptosis, signal transduction, anti-cell injury and hormone metabolism. CONCLUSION: There are obvious differences in expressive proteomes in renal tissue between normoxic and chronic intermittent hypoxic rats. Proteomics can serve as a new approach in the study of obstructive sleep apnea-hypopnea syndrome for discovering new therapeutic targets.     

西施舌鳃蛋白质组学研究

[目的]研究西施舌（Coelomactra antiquate）鳃蛋白质组学。[方法]以西施舌的鳃组织为研究对象,经破碎、裂解和离心等抽提方法提取鳃组织蛋白质样品,利用Bradford蛋白质定量试剂盒作蛋白定量后,进行一向等电聚焦电泳和SDS聚丙烯酰胺凝胶电泳。电泳后的凝胶用考马斯亮蓝染色,利用Image ScannerⅢ扫描仪扫描凝胶,获得凝胶图像。[结果]经研究首次得到西施舌鳃蛋白质双向电泳图谱,初步构建了西施舌鳃蛋白质组的双向电泳技术体系。在pH值为4~7的范围内分布着大部的蛋白质,且多为酸性蛋白。其中,在低pH值区蛋白质分布较多,甚至还出现了高丰度蛋白质,在同一水平线上的蛋白质为分子量相近的蛋白质。[结论]该研究可为进一步探索西施舌鳃组织的生理生化机制奠定基础。     

赤霉素对盐胁迫抑制水稻种子萌发的缓解作用的蛋白质组分析

用粳稻日本晴(Oryza sativa L. cv.Nipponbare),研究了盐胁迫对水稻种子萌发的抑制作用和赤霉酸(GA₃)对盐胁迫的缓解作用;分别以H₂O (对照）,5 g L^-1 NaCl (处理I),5 g L^-1 NaCl + 100 μmol L^-1 GA₃(处理II)培养水稻种苗48 h,提取芽中的蛋白质,利用双向电泳(2-DE)和基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术分析了水稻蛋白质组的变化。结果表明,在盐胁迫条件下,日本晴种子的萌发显著受到抑制,而GA₃能显著缓解这种抑制作用;用ImageMaster软件分析2-DE凝胶,发现有4个蛋白质斑点表现出显著的变化,在盐胁迫下斑点S1、S2和S3表达下调而斑点S4消失,在GA₃与盐共处理时,这4个蛋白质点的表达均有不同程度的恢复;经MALDI-TOF MS分析,其中2个蛋白质斑点(S1,S3)分别被鉴定为isoflavone reductase-like蛋白与葡萄糖磷酸变位酶,这些蛋白可能与GA₃提高水稻耐盐性途径相关。     

东北龙胆花芽蛋白质双向电泳条件的建立

初步建立了东北龙胆(Gentiana manshuica Kitagawa)花芽总蛋白质提取方法,以及东北龙胆花芽蛋白质组研究的双向电泳技术.从样品制备及溶解等方面进行了优化,解决了东北龙胆花芽蛋白质提取中色素、多糖、酚类物质等对双向电泳的干扰,确定了一种有效的蛋白溶解液(7 mol/L尿素,2 mol/L硫脲,4% CHAPS,40 mmol/L DTT,1%蛋白酶抑制剂混合物,2%的两性电解质pH=3～10).同时,对电泳其它环节也进行了优化,经考马斯亮兰染色后,可分辨蛋白质斑点数约1 000个.获得了重复性好、分辨率高的蛋白质双向电泳图谱.     

The proteome research of human lens epithelial cells by two-dimensional gel electrophoresis and mass spectrometry

AIM: To establish the techniques in the proteome research of human lens epithelial cells,including the techniques of two-dimensional electrophoresis and mass spectrometry.METHODS: Total protein of cultured human lens epithelial cells was extracted with two kinds of different methods.The proteins were separated using immobilized pH gradients 2-DE and visualized by silver staining.The digitized images obtained by GS-800 scaner were then analyzed with PDQuest software in order to establish the differential expression profiles.The differential expressed protein spots were cut from the gels using proteomework spot cutter and subjected to in-gel digestion with trypsin.The digested peptide separation was conducted by a Finnigan LCQ MS coupled with a Surveyor HPLC system. RESULTS: A high resolution and reproducible 2-ED image was successfully obtained.The maps of 2-DE showed that lens proteins were in the section of pH 4-7 which the relative molecular weight was 17-72 kD.Relative molecular weight of more abundant proteins was localized at 19-50 kD,as well as the isoelectric points were found to lie between PI 5-7.Two of these proteins were identified by mass spectrometry and database queries.CONCLUSION: A stable protein maps of human lens epithelial cells is constructed.The technique will be used in human lens research to characterize physiological processes and diseases.     

家蚕蚁蚕蛋白质组的质谱鉴定与数据库构建

为尝试构建基于质谱分析的家蚕蛋白质组数据库,采用一维电泳-液相色谱-质谱(1DE-LC-MS)技术对家蚕蚁蚕的蛋白质组进行了分析与鉴定。共检索到511个相匹配的候选蛋白质和92个多肽离子片段,鉴定获得了171个无冗余蛋白质组分,分别属于121种蛋白质或蛋白质亚基,其中有36种蛋白质或亚基尚未在家蚕及昆虫的基因与蛋白质数据库中报道;在171个被鉴定的蛋白质组分中,与细胞骨架和蛋白质代谢相关的组分多达64种。结果还表明,1DE-LC-MS技术也适用于从一维凝胶电泳的差异性条带及蛋白质混合样品中分离和鉴定特异蛋白质组分。