金乌贼脑和视神经节蛋白质组比较分析

采用双向凝胶电泳(2D-PAGE)技术优化分离金乌贼的脑及视神经节全蛋白质, 并选用肽质量指纹谱(Peptide mass fingerprinting, PMF)技术和数据库检索方法对2D-PAGE图谱上的部分蛋白质斑点进行鉴定, 初步构建了金乌贼视神经节(Optic ganglion of Sepia esculenta, SEOG)和脑神经节(Cerebral ganglion of Sepia esculenta, SECG)部分分子解剖图谱. 用Melanie 4 Trial软件分析脑神经节和视神经节蛋白质斑点总数量分别为682和594个, 其中SECG蛋白质斑点数量明显多于SEOG. 在脑神经节和视神经节中均发现了线粒体苹果酸脱氢酶前体(Mitochondrial malate dehydrogenase precursor, pre-MDH)及可溶性NSF连接蛋白(SNAP-type proteins). 此外, 延长因子(Elongation factor G)、微管蛋白(Tubulin)和肌动蛋白(Actin)等蛋白质也具有高匹配率. 已鉴定的蛋白质, 多数归属于假定蛋白和结构蛋白类.     

在镉盐胁迫下扇贝鳃组织应激蛋白的研究

采用透射电子显微镜观察了虾夷盘扇贝(Patinopecten yessoensis)鳃组织细胞的超微结构, 发现镉盐能胁迫鳃组织中的腮丝、细胞核和线粒体产生病变. 利用双向凝胶电泳(2D-PAGE)优化分离扇贝鳃组织的全蛋白, 获得约800个蛋白质斑点, 并筛选出37个由于镉盐胁迫而产生的差异蛋白质斑点. 选用基质辅助激光解吸离子化-飞行时间质谱(MALDI-TOF MS)技术和数据库检索鉴定差异蛋白, 结果发现7个与镉毒性密切相关的蛋白质, 即热休克蛋白70和β-淀粉酶等上调蛋白质及原肌球蛋白、肌动蛋白和钙活化核苷酸酶1等下调蛋白质. 此外, 还发现转录调节子Crp/Fnr家族为低表达蛋白质, 而ABC转运子为高表达蛋白质. 在这些差异蛋白中, 部分蛋白质适合作为连续监测流动海水中镉污染程度及评价其危害性的蛋白指示物.     

差速离心结合蛋白质组学技术研究受镉盐胁迫后的牙鲆肝差异蛋白质

人工构建镉盐污染源,选用差速离心结合双向凝胶电泳(2D-PAGE)法,高效提取、分离和筛选牙鲆(Paralichthys olivaceus, PO)受镉盐胁迫后的肝脏全蛋白和差异蛋白质.实验结果表明: 选用直接裂解法提取牙鲆肝(PO liver POL)全蛋白质且用2D-PAGE分离,可获得约800个蛋白斑点,其中镉盐诱导了11个差异蛋白斑点.以相对离心力为1000×g、12000×g和100000 ×g 的差速离心法,分别制备了3种沉淀蛋白和1种胞浆蛋白,称为POL组分Ⅰ、POL组分Ⅱ、POL组分Ⅲ和POL组分Ⅳ(胞浆蛋白),蛋白斑点数目分别为380、550、500和850个,总计2280个,明显高于直接裂解法.比较分析法发现,差速离心结合2D-PAGE分离技术可获得牙鲆肝脏受镉盐胁迫后表达的54个差异蛋白质,并适合于用肽质量指纹(peptide mass fingerprint,PMF)图谱技术鉴定.本实验所建立的差速离心结合蛋白质组学技术可高效提取、分离和鉴定组织全蛋白或差异蛋白,并能有效地筛选出蛋白指示物.     

蛋白质组学技术筛选与鉴定镉诱导下褐云玛瑙螺肝脏的差异蛋白质

比较丙酮/TCA沉淀法和直接裂解法,优化提取与分离褐云玛瑙螺(Achatina fulica, AF)肝脏全蛋白.采用丙酮/TCA沉淀法,可获得约600个蛋白质斑点.用0.5 mg/L CdCl2溶液浸泡后的去梗小白菜喂养AF,并作为镉盐诱导AF肝脏表达应激蛋白质的实验材料.采用蛋白质组学技术筛选出由镉盐诱导AF肝脏表达的14个差异蛋白质斑点,并用肽质量指纹图谱技术(peptide mass fingerprinting, PMF)和数据库比对法初步鉴定出7种差异蛋白质,其中部分为热激蛋白(heat shock protein)、甲基转移酶(Methyltransferase)、三磷酸腺苷结合盒子转运体(ABC transporter)、钼酸盐转运子亚基(molybdate transporter subunit)和磷酸甘油酸变位酶(phosphoglycerate mutase).差异蛋白质均参与镉盐代谢,并适合作为监测土壤或食物中镉污染程度及危害性的指示蛋白质.     

在镉盐胁迫下用蛋白质组学技术筛选与鉴定海兔亚口腔神经节的差异蛋白质

以蓝斑背肛海兔(Notarcus leachii cirrosus Stimpson, NLCS)的口腔神经节(Buccal ganglion, BG)为研究对象, 按BG形态对称性, 解剖成亚BG(sub-BG, SBG), 并分为左SBG和右SBG, 简称为LSBG和RSBG. 用双向凝胶电泳(2D-PAGE)技术优化分离LSBG和RSBG全蛋白质, 并采用蛋白质组学和数据库比对技术筛选与鉴定差异蛋白质. 实验结果表明, LSBG和RSBG之间的差异蛋白质主要由活性多肽的前体蛋白或降解后大片段多肽组成, 它们对维持BG的生理功能起着重要的作用. 在急性镉盐(10 μg/mL)胁迫下, NLCS的LSBG和RSBG表达了由镉盐诱导的差异蛋白质, 并采用蛋白质组学技术分别分离、筛选和鉴定, 其主要的差异蛋白质有下调的肌球蛋白、钙结合蛋白、上调的热休克蛋白和硫氧还蛋白. 这些蛋白质可能与BG细胞抗镉毒性有关, 部分差异蛋白质适合于监测镉盐污染且开展毒理学研究的蛋白指示物.     

人卵巢癌耐药细胞株的比较蛋白质组分析

本文采用高分辨二维凝胶电泳分离技术对人卵巢癌细胞株COC1及其耐药细胞株COC1/DDP中的蛋白质进行分离和差异表达分析, 应用基质辅助激光解吸电离-飞行时间质谱对酶解多肽进行测定[即测定蛋白质的肽质量指纹图(Peptide mass fingerprinting, PMF)], 并通过相应的数据库搜索来鉴定蛋白质. 为获得更准确的检索结果, 采用串联质谱技术对各肽段进行氨基酸测序, 并应用IPI-HUMAN数据库对上述检索结果进一步加以确认.      

2-酰基-1,3-环己二酮烯醇酯的异构化反应机理

2-酰基-1,3-环二酮类化合物广泛存在于自然界,并且呈现出各种各样的生物活性[1,2].该类化合物的合成一直是有机化学家关注的课题.最近,Yang等[3]在合成一类2-酰基-1,3-环己二酮的衍生物时发现其烯醇酯可在常温下轻易地发生异构化并提出了一种可能的反应机理(如Scheme 1途径A所示).然而,除此机理外,反应物途径两步连续的1,5-迁移过程(即1,5-酰基迁移和1,5-氢迁移)亦可最终得到异构化产物(途径B).通过密度泛函理论计算(B3LYP/6-31G*水平),我们发现途径A中的1,3-氢迁移步骤活化能高达281 kJ/mol.不过,考虑溶剂(三乙基胺)的影响,其活化能降为143 kJ/mol,说明溶剂的存在可大大提高1,3-氢迁移的反应速率.途径B中1,5-酰基迁移和1,5-氢迁移的活化能分别为16.7和90.4 kJ/mol,在能量上明显更为有利,应该是更合理的异构化途径.     

蛋白质组学技术鉴定与分析三七粉诱导海兔神经连索表达的差异蛋白质

RP-HPLC分离三七粉提取液,并鉴定含有Rb1、Rg1、Re、R1等皂甙成分。以蓝斑背肛海兔(Notarcusleachii cirrosus Stimpson,NLCS)为分析模型,三七粉提取液为诱导剂,选用蛋白质组技术研究NLCS神经连索诱导前后所表达的差异蛋白质。通过优化双向凝胶电泳分离NLCS神经连索全蛋白质组技术,获得496个蛋白质斑点。采用肽指纹图谱技术和数据库检索比对法,初步鉴定了NLCS受三七粉提取液诱导前后,其神经连索表达13个差异蛋白质,其中较高的匹配率蛋白质为肌动蛋白、3-羟酯酰辅酶A脱氢酶、ATP结合转运子和甲基转移酶12。选用LOC tree软件对13个差异蛋白质进行亚细胞定位,认为它们在保护神经系统中发挥重要的调节作用。     

中枢神经系统血管母细胞瘤细胞与人脑神经元细胞差异蛋白质分析

以人工培养的中枢神经系统血管母细胞瘤(Central nervous system hemangioblastoma,HB)细胞为研究对象,发展了蛋白质组学分析方法,鉴定了HB细胞与人脑神经元细胞的差异蛋白质.采用在线HPLC串联LTQ-Orbitrap质谱鉴定样品的可溶性蛋白质,得到了HB细胞的蛋白质组表达谱.HB细胞鉴定得到674个蛋白质,神经元细胞鉴定获得531个蛋白质.根据基于肽段鉴定的蛋白质组半定量分析方法对质谱数据进行蛋白质的差异比较分析,发现了波形蛋白(Vimentin),14-3-3 epsilon蛋白和碳酸酐酶Ⅱ(Carbonic anhydrase Ⅱ,CA Ⅱ)等在HB细胞中表达量发生明显变化的蛋白质,并对其进行了免疫组织化学染色分析.结果显示,波形蛋白(Vimentin)、14-3-3 epsilon蛋白以及碳酸酐酶Ⅱ(CA Ⅱ)等蛋白质表达量的改变与HB的发病密切相关,对探索HB的起源有重要意义.     

生物活性复合材料在生物矿化过程中的微观形貌与离子浓度变化

采用3-羟基丁酸酯-3-羟基戊酸酯的共聚物(PHBV)与磷酸三钙(TCP)、羟基磷灰石(HA)、生物活性玻璃(BG)等进行复合,获得了性能优良的生物活性骨组织工程支架材料和骨修复材料.研究和比较了3种复合材料在体外模拟生理环境中发生的生物矿化反应,对比了反应前后因矿化物的形成导致的表面微观形貌的变化,通过检测反应液离子浓度的变化对不同材料的矿化过程和生物活性进行了定量表征.研究结果表明,3种复合材料在模拟生理溶液中发生生物矿化的过程和程度不同,其中PHBV/BG的生物活性反应最为明显.     

质谱法分析2型糖尿病大鼠神经视网膜差异表达蛋白

采用二维电泳(2DE)分离了正常SD大鼠和2型糖尿病模型大鼠神经视网膜组织总蛋白, 并用Image Master 5.0软件分析比较了正常组和糖尿病组2DE图像, 正常组检测到 3122±37(n=3)个蛋白质点; 糖尿病组检测到2702±21(n=3)个蛋白质点. 约150个蛋白质点的表达水平在两组之间存在明显差异(P<0.05). 在糖尿病组中表达上调的点68个, 下调的点82个. 选择20个差异表达蛋白质点进行肽质量指纹谱(PMF)或串联质谱鉴定, 其中7个蛋白已有报道与糖尿病视网膜病变(DR)相关, 10个蛋白尚未见有报道.     

中国小型猪骨髓间充质干细胞的蛋白质组研究

报道了骨髓间充质干细胞(MSCs)的蛋白质组表达研究。从体外培养的MSCs提取细胞蛋白,经二维电泳分离后用银染方法可检出蛋白点约1600个,选取48个蛋白点进行胶内酶解及质谱分析,经数据库检索成功鉴定了37个蛋白,并对蛋白功能进行初步分析。本实验数据为进一步分析MSCs增殖、分化或凋亡的分子机理提供相关信息。     

人脑枕叶区衰老进程的比较蛋白质组学研究

分别从23岁、64岁、72岁、83岁以及94岁无神经性和精神性疾病史个体大脑皮层枕叶区取样．制备蛋白质样晶．进行双向凝胶电泳(2-DE)、考马斯亮蓝染色、凝胶扫描和Image Master 2D Elite软件分析，每张胶上平均可检测到1000个以上蛋白质点．通过软件半定量分析．进一步研究了衰老过程中枕叶蛋白质的差异表达，发现随年龄增长有7种蛋白质有一致的显著上升或下降趋势．应用质谱进行肽质量指纹图谱(PMF)和／或肽序列标签(PST)分析．数据库检索共鉴定了11种蛋白质．其中有5种具有一致的上调或下调性．包括神经元突触结构蛋白低分子量神经丝蛋白(Neurofilament triplet L protein．NF—L)、参与抗氧化反应的硫氧还原蛋白过氧化物酶(Peroxiredoxin)、三羧酸循环关键酶(顺)乌头酸水合酶(Aconitate hydratase)和糖代谢途径中的关键酶烯醇化酶2(Enolase 2)以及分子伴侣蛋白T复合物蛋白l(T-complex protein 1)．首次建立了正常人脑枕叶区的双向电泳蛋白质表达图谱．针对人脑枕叶区蛋白质在衰老过程中的差异表达进行了研究，并对差异表达蛋白在衰老进程中可能的生物学意义做了探讨．     

Iterative data analysis is the key for exhaustive analysis of peptide mass fingerprints from proteins separated by two-dimensional electrophoresis

Peptide mass fingerprinting (PMF) is a powerful tool for identification of proteins separated by two-dimensional electrophoresis (2-DE). With the increase in sensitivity of peptide mass determination it becomes obvious that even spots looking well separated on a 2-DE gel may consist of several proteins. As a result the number of mass peaks in PMFs increased dramatically leaving many unassigned after a first database search. A number of these are caused by experiment-specific contaminants or by neighbor spots, as well as by additional proteins or post-translational modifications. To understand the complete protein composition of a spot we suggest an iterative procedure based on large numbers of PMFs, exemplified by PMFs of 480 Helicobacter pylori protein spots. Three key iterations were applied: (1) Elimination of contaminant mass peaks determined by MS-Screener (a software developed for this purpose) followed by reanalysis; (2) neighbor spot mass peak determination by cluster analysis, elimination from the peak list and repeated search; (3) re-evaluation of contaminant peaks. The quality of the identification was improved and spots previously unidentified were assigned to proteins. Eight additional spots were identified with this procedure, increasing the total number of identified spots to 455.     

Cross-matching marsupial proteins with eutherian mammal databases: proteome analysis of cells from UV-induced skin tumours of an opossum (Monodelphis domestica)

The identification and characterisation of Monodelphis proteins has required cross-species analysis. Protein expression was investigated in normal, nonirradiated adult fibroblasts and also in fibroblastic cells from a benign cutaneous tumour after chronic ultraviolet (UVB) exposure and a metastatic cutaneous tumour after intermittent exposure. Proteins were separated and visualised by two-dimensional gel electrophoresis (2-D PAGE) and a peptide mass fingerprint (PMF) was obtained for protein spots using matrix assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDITOF-MS). Cross-species PMF database analysis facilitated the identification of 120 proteins, constituting 46.5% of the proteins analysed. The identification of two proteins was confirmed by internal amino acid sequencing using tandem MS. Differential protein expression was observed between normal fibroblasts and those in tumours chronically or intermittently exposed. A number of tropomyosin and vimentin isoforms were expressed only in cells from the metastatic tumour induced by intermittent exposure to UV radiation. These results highlight the value of cross-species PMF analysis for the rapid characterisation of proteins from a poorly defined species and also show how proteomics can be used to detect changes in protein expression in differentially treated cells.     

蛋白质组学技术筛选与鉴定在甲基对硫磷胁迫下牙鲆脑组织表达的差异蛋白质

以甲基对硫磷(MP)为有机磷农药污染源,采用蛋白质组学技术分离及鉴定在甲基对硫磷胁迫下,牙鲆(Paralichthys olivaceus)脑组织表达的差异蛋白质,从中筛选出潜在的适合于监测甲基对硫磷污染程度的蛋白指示物。实验结果表明:在甲基对硫磷胁迫下,牙鲆脑组织表达出17个差异蛋白质,经肽质量指纹(PMF)图谱技术鉴定后,发现其中部分差异蛋白质为热休克蛋白、细胞色素P450和谷胱甘肽S-转移酶,均是与受甲基对硫磷胁迫有关的蛋白质。     

大鼠骨髓间充质干细胞分化过程的比较蛋白质组学研究

从蛋白质组学角度分析大鼠骨髓间充质干细胞(MSCs)体外定向分化为心肌细胞过程中蛋白表达情况, 采用二维电泳分离蛋白, 用PDQuest软件分析蛋白表达差异, 并采用质谱(MALDI-TOF-MS)进行鉴定, 得到了54个蛋白点, 对蛋白的生物功能分析表明, 部分蛋白通过不同的信号途径参与了MSCs的分化过程.     

Alkaline extraction of human plasma proteins from nondenaturing micro-2-D gels for protein/polypeptide mass measurement and peptide mass fingerprinting using MALDI-TOF MS

Previously, we have reported a high-efficiency method of protein extraction from CBB-stained polyacrylamide gels for molecular mass measurement with MALDI-TOF MS [1]. In the present work, the alkaline extraction method was applied to CBB-stained 2-DE gels on which human plasma proteins were separated in the absence of denaturant. In order to examine the performance of the method, ten spots with apparent molecular masses (MMapp) in the range of 65 to 1000 kDa were selected and the proteins were extracted from the gel pieces. The extracts were subjected to whole-mass measurement by MALDI-TOF MS, with and without DTT treatment. In addition, the extracts were subjected to in-solution trypsin digestion followed by MALDI-TOF MS and PMF analysis. Successful extraction of proteins from the ten spots, up to MMapp 1000 kDa, has been ascertained by the significant PMF assignment (MASCOT) with high sequence coverage of the respective proteins or polypeptides. When direct mass measurement of the extracted proteins was attempted, three spots in MMapp range 65-100 kDa provided mass peaks. Five spots in MMapp range 150-400 kDa did not give mass peaks of the intact proteins, but showed those of the constituent polypeptides after the DTT treatment. Extraction of proteins prior to trypsin digestion enabled the procedure of PMF analysis to be much simpler than the conventional in-gel digestion method, providing comparable protein scores and sequence coverage. The technique presented here suggests a new strategy for the characterization of proteins separated by nondenaturing 2-DE.     

Different protein expression of myocardium from Chinese mini-swine model of myocardial infarct

High-resolution two-dimensional gel electrophoresis (2-DE), followed by computer-assisted image analysis was used to screen protein patterns of normal and infarcted myocardial tissues for quantitative and qualitative differences in protein expression. In the gels of pH 5–8 immobilized pH gradient (IPG) strips, 851 protein spots were detected in normal myocardial tissue and 1 032 protein spots were resolved in infarcted myocardial tissue. Thirteen protein spots only expressed in normal myocardial tissue, and 14 protein spots only expressed in infarcted myocardial tissue. Results also showed that 49 protein spots displayed quantitative changes in expression between normal and infarcted myocardial tissue. Eleven protein spots were subjected to mass spectrometry (MS) analysis and seven proteins were identified by peptide mass fingerprinting (PMF). These proteins may be involved in cardiovascular injury, and could play an important role in the treatment of coronary heart disease. __________ Translated from Chemical Journal of Chinese Universities, 2006, 8(27): 1467–1471 [译自: 高等学校化学学报]     

Assignment of human plasma polypeptides on a nondenaturing 2-D gel using MALDI-MS and PMF and comparisons with the results of intact protein mapping

Human plasma proteins were separated by 2-DE under nondenaturing conditions followed by the assignment of the CBB-stained spots using MALDI-MS and PMF, aiming to correlate the information of intact proteins with that of constituent polypeptides. A microgel system was employed to facilitate the analysis. Totally 157 spots on a nondenaturing micro-2-DE gel were numbered, the spots were excised, the proteins in the gel pieces were subjected to in-gel digestion with trypsin followed by polypeptide analysis using MALDI-MS and PMF. Two PMF algorithms, MASCOT (with Swiss-Prot database) and ProFound (with NCBInr database) were employed. A total of 153 spots out of the 157 provided significant match (p <0.05) with polypeptides in databases. Eighty spots were assigned to contain multiple (2-4) polypeptides, suggesting (i) noncovalent interaction between proteins/polypeptides, (ii) disulfide bonding of polypeptides, or (iii) overlapping of the protein locations on the gel. The results of polypeptide assignment coincided very well with the results of protein mapping previously reported, in which 33 plasma proteins were identified using blotting-immunochemical staining (Manabe, T., Takahashi, Y., Higuchi, N., Okuyama, T., Electrophoresis 1985, 6, 462-467). Further, 19 polypeptides in 25 spots were newly assigned. These results demonstrate that the techniques of MALDI-MS and PMF can be applied for analysis of proteins separated on nondenaturing 2-DE gels, providing information on their polypeptide structure. The integrated information on proteins and polypeptides would help the comprehensive understanding on the functions of complex protein systems.