Proteomics analysis of cerebral cortex in Wistar rats

To analyze the protein expression pattern of the cerebral cortex in Wistar rats using the proteomics approach, proteins were separated by two-dimensional gel electrophoresis, stained with Coomassie brilliant blue and digested with trypsin. Then, we analyzed the peptide section using a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and identified the protein by indexing special database (SwissProt) according to the finger printing of the peptide quality. Eighty-four protein spots were identified, includ-ing metabolic enzymes, skeleton proteins, heat shock pro-teins, antioxidant proteins, signaling proteins, proteasome related proteins, neuron and glial specific proteins and serum associated proteins. The result of this study enriches the database of the proteome in the cerebral cortex of rats and lays a foundation for further research of neurological disorders in rat models.     

大鼠脑皮质表达蛋白质组学研究

文章用蛋白质组学方法初步分析大鼠脑皮质蛋白质的表达。提取大鼠脑皮质蛋白质,双向凝胶电泳分离,考马斯亮蓝染色,胰蛋白酶胶内酶解,用基质辅助激光解吸/电离飞行时间质谱对酶解后的肽段进行分析,根据肽质量指纹图谱,检索专业数据库(Swissprot),对蛋白质进行鉴定。鉴定出84个蛋白,分别属于代谢酶、细胞骨架蛋白、热休克蛋白、抗氧化蛋白、信号传导蛋白、蛋白酶体相关蛋白、神经元特异蛋白及神经胶质蛋白等。文章结果丰富了大鼠脑皮质蛋白质组数据库,为在大鼠模型上研究神经疾病奠定了基础。     

正常与脑缺血大鼠的脑皮质蛋白质差异分析鉴定

Wistar大鼠随机分为正常组和模型组,采用改进的线栓法制备模型,在规定的时间点快速断头取脑,分离脑皮质组织,提取蛋白质后双向电泳展示,以ImageMaster 2D Elite v301软件对2_DE图谱进行差异表达分析,目标蛋白点用基质辅助激光解析电离质谱测定肽质量指纹图进行鉴定。线粒体应激70蛋白前体、血小板活化因子乙酰基水解酶Ibβ亚单位、ADP核糖基化因子蛋白3、电压依赖性阴离子选择通道蛋白1、泛素C末端水解酶同工酶L1、突触结合蛋白等11个蛋白在模型6h组表达上调,谷胱甘肽S-转移酶omega 1、 谷胱甘肽S-转移酶P、Cu-Zn超氧化物歧化酶、 ATP合酶D链、G蛋白β亚单位1、微管蛋白β链15、苹果酸脱氢酶等15个蛋白在模型6h组表达上调。胆绿素还原酶B、细胞因子A4前体为模型组新出现点,腺苷酸激酶同工酶1在模型组消失,Thiore doxin peroxidase 1在模型组分为2个点。以双向电泳技术得到分辨率较好的电泳图谱,并初步鉴定脑缺血后差异表达蛋白,为深入研究缺血性脑损伤病理机制奠定了基础。     

正常与重金属铅注射的兔脑蛋白质双向电泳图谱比较与鉴定

重金属污染对人类健康的威胁日益受到关注,为了了解大量重金属摄入对脑蛋白质的影响,对比研究了正常兔脑组织蛋白质与重金属铅腹腔注射2周后的兔脑组织在蛋白质双向电泳图谱中的差异,分析重金属注射对脑蛋白质表达的可能影响.通过对脑组织蛋白质的提取,分离出水溶性的蛋白质组分,经双向电泳图谱比较正常与注射重金属铅的兔子在脑蛋白质表达上的差异,其中3个蛋白质斑点经提取,反相高效液相色谱(RP-HPLC)分离,基质辅助激光解析电离质谱(MALDI-TOF MS)确定了分子质量,并利用肽质量指纹图谱检索数据库确定蛋白质的归属.实验结果表明正常兔脑与金属铅注射的兔脑在水溶性蛋白质的表达上具有显著性差异.     

Global changes in phospholipids identified by MALDI MS in rats with focal cerebral ischemia

Neuronal membrane phospholipids are highly affected by oxidative stress caused by ischemic injury. Thus, it is necessary to identify key lipid components that show changes during ischemia to develop an effective approach to prevent brain damage from ischemic injury. The recent development of MALDI imaging MS (MALDI IMS) makes it possible to identify phospholipids that change between damaged and normal regions directly from tissues. In this study, we conducted IMS on rat brains damaged by ischemic injury and detected various phospholipids that showed unique distributions between normal and damaged areas of the brain. Among them, we confirmed changes in phospholipids such as lysophosphatidylcholine, phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin by MALDI IMS followed by MS/MS analysis. These lipids were present in high concentrations in the brain and are important for maintenance of cellular structure as well as production of second messengers for cellular signal transduction. Our results emphasize the identification of phospholipid markers for ischemic injury and successfully identified several distinctly located phospholipids in ischemic brain tissue.     

Identification of differentially expressed proteins in poplar leaves induced by Marssonina brunnea f. Sp. Multigermtubi

Black spot disease in poplar is a disease of the leaf caused by fungus. The major pathogen is Marssonina brunnea f. sp. multigermtubi. To date, little is known about the molecular mechanism of poplar （M. brunnea） interaction. In order to identify the proteins related to disease resistance and understand its molecular basis, the clone ＂NL895＂ （P. euramericana CL＂NL895＂）, which is highly resistant to M. brunnea f. sp. multigermtubi, was used in this study. We used two-dimensional gel electrophoresis （2-DE） and mass spectrometry （MS） to identify the proteins in poplar leaves that were differentially expressed in response to black spot disease pathogen, M. brunnea f. sp. multigermtubi. Proteins extracted from poplar leaves at 0, 12, 24, 48, and 72 h after pathogen-inoculation were separated by 2-DE, About 500 reproducible protein spots were detected, of which 40 protein spots displayed differential expression in levels and were subjected to Matrix assisted laser desorption/ionization time of flight mass spectrometry （MALDI-TOF MS） followed by database searching. According to the function, the identified proteins were sorted into five categories, that is, protein synthesis, metabolism, defense response and unclassified proteins.     

大豆种子萌发过程中的差异蛋白质组研究

运用蛋白质组学技术对大豆(Glycinemax)N2899种子萌发0h、8h、36h、60h4个时期蛋白质的差异表达情况进行了研究.结果发现,在考马斯亮蓝染色的双向电泳pH3～10胶上,PDQuest图像分析软件可识别的点约350个,其中表达量变化2.5倍以上的蛋白质点有24个,而绝大部分大豆种子贮藏蛋白在萌发期尚未降解.在萌发的第一阶段,24个差异表达蛋白中有10个蛋白质的丰度发生变化.第二阶段,差异表达蛋白的种类和量增加,其中15个蛋白质是动态变化的,14个蛋白质在胚根突破种皮时表达量达到峰值,表明吸胀后种子内的生命活动越来越强.对这24个蛋白质点进行胶内酶解,用基质辅助激光解析电离飞行时间质谱测定均获得肽质量指纹图谱.搜索大豆的UniGene库初步鉴定出6个蛋白质,分别是核苷二磷酸激酶、热激蛋白、硫氧还蛋白、35ku种子成熟蛋白及种子成熟蛋白PM36.对这些蛋白质在种子萌发过程中可能的作用进行了讨论.     

用双向电泳和质谱技术检测NGX6转染后人鼻咽癌细胞表达差异的蛋白质(英)

NGX6是克隆的鼻咽癌相关基因,它的功能与作用机制目前尚不十分清楚.通过脂质体转染把NGX6导入鼻咽癌细胞株中,采用双向凝胶电泳分离细胞内所有蛋白质,通过软件分析,找到与未处理细胞表达差异的蛋白质,通过质谱分析和生物信息学资料处理.鉴定出七种表达上调的蛋白质,其中包括Fas蛋白,锌指蛋白（ZNF）,主要组织相容性抗原Ⅱ（MHCⅡ）等.Fas蛋白参与细胞凋亡的信号传导途径,它的上调可以促进细胞凋亡;ZNF蛋白参与基因的转录调控,它的上调也可影响细胞异常增殖的信号传导通路;MHCⅡ可以促进机体对肿瘤细胞的免疫应答.这些结果说明NGX6可能通过多种途径抑制鼻咽癌细胞的生长,为研究NGX6的作用机制提供了很好的实验资料,对鼻咽癌的基因治疗奠定了一定的研究基础,也为研究其他基因的作用机制提供了新思路.     

后基因组时代的植物蛋白质组学

蛋白质组学是后基因组时代功能基因组学研究的新兴学科和热点领域.简要介绍了蛋白质组学产生的科学背景、研究内容和研究方法.重点综述了植物个体水平、组织、器官和亚细胞水平蛋白组研究,植物蛋白质组学在植物遗传多样性、遗传突变体、植物的逆境生理等方面的研究进展.最后展望了今后的发展前景.     

蛋白质组学技术及其在生物医学上的应用

蛋白质组学部分承用了创立于二十多年前的二维电泳技术。基于其高分辩能力 ,二维电泳主要用于分离和检测复杂混合物中的蛋白质。虽然没有获得更多的改进 ,但是二维电泳结合了通过质谱测定蛋白质的最新进展而成为蛋白质组学中的一项重要技术。随着人类基因组计划项目的完成及由此而产生的大量基因数据库和使用这些数据的生物信息技术 ,科学家们的下一个目标是解析生物体的完整蛋白质组 ,把蛋白质组学数据与基因组学数据关联起来并有机地结合而成为一项有力的工具以阐明病理学中的蛋白质功能、衰老的过程及发现新药目标蛋白质和疾病标识物等。文章综述了蛋白质组学技术的最新知识及其在生物医学研究中的潜在应用     

Proteomic Alterations of Antarctic Ice Microalga Chlamydomonas sp. Under Low-Temperature Stress

Antarctic ice microalga can survive and thrive in cold channels or pores in the Antarctic ice layer. In order to understand the adaptive mechanisms to low temperature, in the present study we compared two-dimensional polyacrylamide gel electrophoresis （2-DE） profiles of normal and low temperature-stressed Antarctic ice microalga Chlamydomonas sp. cells. In addition, new protein spots induced by low temperature were identified with peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） and database searching. Well-resolved and reproducible 2-DE patterns of both normal and low temperature-stressed cells were acquired. A total of 626 spots was detected in control cells and 652 spots were detected in the corresponding low temperature-stressed cells. A total of 598 spots was matched between normal and stressed cells. Two newly synthesized proteins （a and b） in low temperature-stressed cells were characterized. Protein spot A （53 kDa, pl 6.0） was similar to isopropylmalate/homocitrate/citramalate synthases, which act in the transport and metabolism of amino acids. Protein spot b （25 kDa, pl 8.0） was related to glutathione S-transferase, which functions as a scavenger of active oxygen, free radicals, and noxious metabolites. The present study is valuable for the application of ice microalgae, establishing an ice microalga Chlamydomonas sp. proteome database, and screening molecular biomarkers for further studies.     

Mass spectrometric identification and microcharacterization of proteins from electrophoretic gels: Strategies and applications

The entire genomic DNA sequences of a number of prokaryotic and eukaryotic species are now available and many more, including the human genome, will be completed in the near future. The state-of-life of a cell at any given time, however, is defined by its protein composition, i.e., its proteome. Gel electrophoresis, mass spectrometry, and bioinformatics will be important tools for protein and proteome analysis in the post-genome era. Protein identification from electrophoretic gels by mass spectrometric peptide mapping or peptide sequencing combined with sequence database searching is established and has been applied to numerous biological systems. We describe current strategies and selected applications in molecular and cell biology. The next challenges are detailed structure/function analyses, which include studying the molecular composition of multiprotein complexes and characterization of secondary modifications of proteins. The advantages and limitations of a number of mass spectrometry-based strategies designed for microcharacterization of low amounts of protein from electrophoretic gels are discussed and illustrated by examples. Proteins Suppl. 2:74–89, 1998. © 1998 Wiley-Liss, Inc.     

Proteome analysis of silk gland proteins from the silkworm, Bombyx mori

The silk gland of Bombyx mori is an organ specialized for the synthesis and secretion of silk proteins. We report here the resolution of silk gland proteins by 2-DE and the identification of many of those proteins. This was accomplished by dissecting the glands into several sections, with each exhibiting more than 400 protein spots by 2-DE, of which 100 spots were excised and characterized by in-gel digestion followed by PMF. Ninety-three proteins were tentatively identified. These were then categorized into groups involved in silk protein secretion, transport, lipid metabolism, defense, etc. Western blotting of a 2-DE gel using an antibody of the carotenoid binding protein confirmed the presence of this protein in the silk gland. Proteins including fibroin L-chain and P25 were found as multiple isoforms, some of which contained differential amounts of phosphate residues as analyzed by on-probe dephosphorylation. The current analysis contributes to our understanding of proteins expressed by the silk gland not only of the model lepidopteran B. mori, but also to proteins from other silk-producing insects such as Philosamia cynthia ricini.     

Differential proteomic analysis during the vegetative phase change and the floral transition in Malus domestica

In order to identify the proteomic changes of apple (Malus domestica Borkh.) during the vegetative phase change and the floral transition, leaf protein of juvenile, adult vegetative and reproductive phase in a seedling ('Jonathan' × 'Golden Delicious') was extracted and analyzed by 2-D electrophoresis and Matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Seventy two gel spots with significant expression differences between ontogenetic phases were obtained. Five protein spots were only detected in leaves of juvenile phase and 11 were not; 17 spots were found exclusively in adult vegetative leaves; and only one spot solely appeared in reproductive leaves while 12 did not. Twenty six of the differentially expressed proteins identified were involved in photosynthesis. Seven enzymes were related to respiration and carbohydrate metabolism. Fifteen other proteins also presented qualitative or quantitative differences among developmental phases. The spatial distribution of one differentially expressed protein, serine hydroxymethyltransferase, was confirmed by enzyme linked immunosorbent assay and immunohistochemistry. These results strongly support the idea that the vegetative phase change and the floral transition are regulated independently during developmental process.     

一种SDS-PAGE与MALDI-TOF质谱联用的方法

以尿激酶的为材料,探索一种从ＳＤＳ－ＰＡＧＥ胶上回收蛋白 做ＭＡＬＤＩ－ＴＯＦ质谱的方法,所用的回收方法包括电洗脱、脱盐、除ＳＤＳ等过程,电洗脱用的是高盐阻断法,脱盐用的超滤技术,去除ＳＤＳ用的是冷丙沉淀法,结果证明,此方法至少对一些蛋白质是可行的。     

Inhibition of hybrid- and complex-type glycosylation reveals the presence of the GlcNAc transferase I-independent fucosylation pathway

A mammalian N-acetylglucosamine (GlcNAc) transferase I (GnT I)-independent fucosylation pathway is revealed by the use of matrix-assisted laser desorption/ionization (MALDI) and negative-ion nano-electrospray ionization (ESI) mass spectrometry of N-linked glycans from natively folded recombinant glycoproteins, expressed in both human embryonic kidney (HEK) 293S and Chinese hamster ovary (CHO) Lec3.2.8.1 cells deficient in GnT I activity. The biosynthesis of core fucosylated Man5GlcNAc2 glycans was enhanced in CHO Lec3.2.8.1 cells by the alpha-glucosidase inhibitor, N-butyldeoxynojirimycin (NB-DNJ), leading to the increase in core fucosylated Man5GlcNAc2 glycans and the biosynthesis of a novel core fucosylated monoglucosylated oligomannose glycan, Glc1Man7GlcNAc2Fuc. Furthermore, no fucosylated Man9GlcNAc2 glycans were detected following inhibition of alpha-mannosidase I with kifunensine. Thus, core fucosylation is prevented by the presence of terminal alpha1-2 mannoses on the 6-antennae but not the 3-antennae of the trimannosyl core. Fucosylated Man5GlcNAc2 glycans were also detected on recombinant glycoprotein from HEK 293T cells following inhibition of Golgi alpha-mannosidase II with swainsonine. The paucity of fucosylated oligomannose glycans in wild-type mammalian cells is suggested to be due to kinetic properties of the pathway rather than the absence of the appropriate catalytic activity. The presence of the GnT I-independent fucosylation pathway is an important consideration when engineering mammalian glycosylation.     

一种SDS-PAGE与MALDI-TOF质谱联用的方法

以尿激酶原为材料,探索一种从SDS-PAGE胶上回收蛋白质做MALDI-TOF质谱的方法.所用的回收方法包括电洗脱、脱盐、除SDS等过程.电洗脱用的是高盐阻断法,脱盐用的是超滤技术,去除SDS用的是冷丙酮沉淀法.结果证明,此方法至少对一些蛋白质（如尿激酶原和牛血清白蛋白）是可行的.     

Proteomic analysis of differential protein expression in response to epidermal growth factor in neonatal porcine pancreatic cell monolayers

We have proposed that porcine neonatal pancreatic cell clusters (NPCCs) may be a useful alternative source of cells for islet transplantation, and that monolayer cultures might provide an opportunity to manipulate the cells before transplantation. In addition we previously identified 10 genes up-regulated by epidermal growth factor (EGF) in cultured porcine NPCC monolayers. We have now analyzed the intracellular signaling pathways activated by EGF and searched for proteins differentially expressed following EGF treatment of the monolayers, using two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). EGF treatment resulted in phosphorylation of both Erk 1/2 and Akt, as well as increased cell proliferation. Five unknown and 13 previously identified proteins were differentially expressed in response to EGF. EGF treatment increased the expression of several structural proteins of epithelial cells, such as cytokeratin 19 and plakoglobin, whereas vimentin, the intermediate filament protein of mesenchymal cells, and non-muscle myosin alkali chain isoform 1, decreased. Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 factor, which promotes epithelial cell proliferation, and hemoglobin alpha I & II also increased, whereas cyclin A1, immunoglobulin heavy chain, apolipoprotein A1, 5,10-ethylenetetrahydrofolated reductase (5,10-MTHFR), angiotensin-converting enzyme 2 (ACE2), co-lipase II precursor, and NAD+ isocitrate dehydrogenase (NAD+ IDH) alpha chain proteins decreased. Our results show that EGF stimulates proliferation of pancreatic epithelial cells by simultaneously activating the MAPK and PI-3K pathways. HnRNP A2/B1, hemoglobin, cyclin A1, and ACE2 may play roles in the proliferation of epithelial cells in response to EGF.     

Proteome analysis of human hepatocellular carcinoma tissues by two-dimensional difference gel electrophoresis and mass spectrometry

Proteome analysis of human hepatocellular carcinoma tissues was conducted using two-dimensional difference gel electrophoresis coupled with mass spectrometry. Paired samples from the normal and tumor region of resected human liver were labeled with Cy3 and Cy5, respectively while the pooled standard sample was labeled with Cy2. After analysis by the DeCyder software, protein spots that exhibited at least a two-fold difference in intensity were excised for in-gel tryptic digestion and matrix-assisted laser desorption/ionization-time of flight mass spectrometry. A total of 6 and 42 proteins were successfully identified from the well- and poorly-differentiated samples, respectively. The majority of these proteins are related to detoxification/oxidative stress and metabolism. Three down-regulated metabolic enzymes, methionine adenosyltransferase, glycine N-methyltransferase, and betaine-homocysteine S-methyltransferase that are involved in the methylation cycle in the liver are of special interest. Their expression levels, especially, methionine adenosyltransferase, seemed to have a major influence on the level of S-adenosylmethionine (AdoMet), a vital intermediate metabolite required for the proper functioning of the liver. Recent work has shown that chronic deficiency in AdoMet in the liver results in spontaneous development of steatohepatitis and hepatocellular carcinoma, and hence the down-regulation of hepatic methionine adenosyltransferase in our hepatocellular carcinoma samples is in line with this observation. Moreover, when a comparison is made between the differentially expressed proteins from our human hepatocellular carcinoma samples and from the liver tissues of knockout mice deficient in methionine adenosyltransferase, there is a fairly good correlation between them.