应用三维鸟枪法串联质谱技术研究脊髓室管膜瘤及正常脊髓室管膜的蛋白表达谱

目的 探讨应用三维鸟枪法( Shot-gun)串联质谱分析技术研究脊髓室管膜瘤和正常室管膜蛋白表达谱的可行性.方法 分别采集8例脊髓室管膜瘤标本和4例室管膜标本获取蛋向,进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE),考马斯亮篮染色、切胶和酶解,串联质谱获取肽质量指纹图谱并鉴定和生物信息学分析. 结果 室管膜组鉴定组2758蛋白,室管膜瘤组鉴定2721个蛋白.其中1631个蛋白质在肿瘤组和对照组均有表达,1090个蛋白质仅在肿瘤组中表达,1127个蛋白质仅在对照组中表达.结论 SDS-PAGE 三维Shot-gun串联质谱技术为定量比较蛋白组学研究脊髓室管膜瘤奠定了技术平台.     

细胞裂解液对蛋白质定量方法的影响

目的:观察不同细胞裂解液对Bradford法和bicinchoninic acid(BCA)法的影响,以确定适合蛋白质组学研究中细胞全蛋白含量的定量方法。方法:采用Bradford法和BCA法测定牛血清白蛋白(bovine serum albumin,BSA)样品溶液,样品BSA溶液分别由双蒸水和不同裂解液(荧光差异双向凝胶电泳裂解液、三种传统双向凝胶电泳裂解液)配制;然后,采用这两种方法测定上述裂解液所提取的细胞全蛋白样品;采用Bradford法定量反复冻融、不同比色杯和不同时期标准曲线下的样品。结果:各细胞裂解液对Bradford法均有显著性影响,使所定量的BSA浓度普遍偏高1.2至2倍,但定量值可随着加样浓度的增加而增加(r=0.989~0.996,P<0.05);各裂解液对BCA法也均有显著性的干扰,多数定量结果超出仪器读数范围;对于同批全蛋白溶液样品,BCA法的定量结果与Bradford法相比可有千倍差异;反复冻融后蛋白浓度变化统计学上无显著性差异,但有下降趋势,不同比色杯和不同时期标准曲线对Bradford法无显著影响。结论:Bradford法是蛋白质组学中细胞全蛋白定量的较适方法,但需根据具体实验进行优化。     

人结核分枝杆菌和牛结核分枝杆菌差异蛋白质组学的研究

目的 探讨人MTB标准株H37Rv与牛分枝杆菌标准株卡介苗株的亚细胞蛋白质组学差异.方法 应用密度梯度离心法分离H37Rv和卡介苗株的细胞壁、细胞膜和细胞质蛋白,利用二维液相色谱分离技术进一步获得H37Rv和卡介苗株亚细胞蛋白质组,采用酶联免疫吸附试验分别检测H37Rv和卡介苗各组分与结核病患者和健康人各5例血清的免疫学反应.组间比较采用t检验.结果 共获得26个特异性引发免疫反应的H37Rv菌株蛋白组分.细胞膜组分M3Fr18与结核病患者的血清免疫学反应的吸收光度(A450值)为(721±3)×10-3,明显高于健康人[(356±6)×10-3],也明显高于卡介苗株细胞膜相应组分与健康人的血清免疫学反应强度[(414±7)×10-3],差异均有统计学意义(t值分别为1.852和1.037,均P＜0.01).细胞膜组分MI0Fr21与结核病患者的血清免疫学反应的A450值为(954±6)×10-3,明显高于健康人[(415±6)×10-3],也明显高于卡介苗株细胞膜相应组分与健康人的血清免疫学反应强度[(315±4)×10-3],差异均有统计学意义(t值分别为2.113和2.550,均P＜0.01).结论 二维液相色谱和酶联免疫吸附试验联合应用,有助于检测人MTB感染的相关抗原蛋白.M3Fr18和M10Fr21蛋白质组分可引起结核病患者的特异性免疫反应,提示其可能是人MTB感染的特异抗原.

Abstract：

Objective To compare the proteome of Mycobacterium tuberculosis (MTB) H37 Rv strain with Bovine mycobacterium (Bacillus Calmette-Guerin, BCG) strain at the sub-cellular level. Methods Proteins of the cell wall, membrane and cytolymph of H37 Rv and BCG were extracted by density gradient centrifugation. Sub-cellular proteome of H37 Rv and BCG were analyzed using 2-dimensional liquid chromatography. The immunity reactions of H37 Rv fractions with sera from patients ( n = 5 ) and healthy controls ( n = 5 ), as well as BCG fractions with sera from healthy controls ( n = 5 ) were analyzed by ELISA.Data was analyzed by t test. Results Twenty-six fractions of H37 Rv were found to elicit specific antibody response. Fraction M3Fr18 of H37 Rv reacted with sera from patients. The A450 [ (721 ± 3 ) × 10-3] was higher than that with sera from healthy controls [ ( 356 ± 6) × 10 - 3 ] , as well as the A450 of the corresponding fractions of BCG with sera from healthy controls [ (414 ± 7) × 10-3 ]. The differences between the patient group and the 2 healthy control groups were significant ( t = 1. 852 and 1. 037, all P ＜ 0. 01 ). Moreover,fraction M10Fr21 of H37Rv reacted with sera from the patients. The A450[ (954 ±6) × 10 -3 ] was higher than that with sera from the healthy controls [ (415 ± 6 ) × 10-3 ], as well as the A450 of the corresponding fractions of BCG with sera from the healthy controls [ ( 315 ± 4 ) × 10-3 ]. The differences between the patient group and the 2 healthy control groups were significant ( t = 2. 113 and 2. 550, all P ＜ 0. 01 ).Conclusions The combination of 2-dimensional liquid chromatography and immunology technology is useful in finding antigens associated with MTB infection. Fractions M3Fr18 and M10Fr21 can elicit specific immune reaction among MTB patients, suggesting that they may be specific antigens of MTB infection.     

Motility of Pseudomonas aeruginosa contributes to SOS-inducible biofilm formation

DNA-damaging antibiotics such as ciprofloxacin induce biofilm formation and the SOS response through autocleavage of SOS-repressor LexA in Pseudomonas aeruginosa. However, the biofilm-SOS connection remains poorly understood. It was investigated with 96-well and lipid biofilm assays. The effects of ciprofloxacin were examined on biofilm stimulation of the SOS mutant and wild-type strains. The stimulation observed in the wild-type in which SOS was induced was reduced in the mutant in which LexA was made non-cleavable (LexAN) and thus SOS non-inducible. Therefore, the stimulation appeared to involve SOS. The possible mechanisms of inducible biofilm formation were explored by subproteomic analysis of outer membrane fractions extracted from biofilms. The data predicted an inhibitory role of LexA in flagellum function. This premise was tested first by functional and morphological analyses of flagellum-based motility. The flagellum swimming motility decreased in the LexAN strain treated with ciprofloxacin. Second, the motility-biofilm assay was performed, which tested cell migration and biofilm formation. The results showed that wild-type biofilm increased significantly over the LexAN. These results suggest that LexA repression of motility, which is the initial event in biofilm development, contributes to repression of SOS-inducible biofilm formation.     

A two-dimensional electrophoresis reference map of human ovary

The ovary plays a central role in oogenesis and gonadal hormone secretion. Proteomic analysis is a valuable approach for gaining an increased understanding of the molecular nature of the ovary. In this work, two-dimensional electrophoresis for protein separation followed by matrix-assisted laser desorption/ionization mass spectrometry and database searches, identified 231 protein spots corresponding to 138 individual proteins that were found in gels representing both the follicular and luteal phases. The data were used to construct a database online (). The identified proteins were functionally classified into seven groups: (1) cell signaling/communication, (2) cell division, (3) gene/protein expression, (4) metabolism, (5) cell structure and motility, (6) cell/organism defense, and (7) unclassified. Among the proteins identified, 47% had not been previously reported in the human ovary. In addition, a number of disease-related proteins were identified in this protein map, including some cancer- and polycystic ovarian syndrome-related proteins. Two proteins with phosphorylation were verified by Western blot analysis. Comparison of protein abundance between follicular and luteal stages produced seven protein spots that had been identified in our database. This study provides a preliminary reference map of normal human ovary that will form a basis for comparative studies on normal and pathological conditions of the human ovary and may serve as a potential tool for clinical diagnosis, therapeutics, and prognosis.Electronic Supplementary Material Supplementary material is available in the online version of this article at L. Wang and Y.-F. Zhu contributed equally to this work     

Systems biology: integrating technology,biology, and computation

The Human Genome Project has changed the worlds of biology and medicine-helping to catalyze two major paradigm changes: systems biology and predictive, preventive and personalized medicine. These two themes will dominate 21st century biology and medicine. I will discuss these changes and indicate how they may interface with with the process of aging.     

蛋白质组学在肝癌发生机制及诊治中的作用

原发性肝癌的发生、发展涉及一系列多基因参与、多步骤协同的复杂过程,通过DNA序列无法解释所有的生物功能,同样的基因组却表达出不同的蛋白质,显示出不同的生物学功能.通过检测肝癌细胞、组织及外周血清蛋白质表达谱,深入开展肝癌发生、发展、复发与转移相关蛋白质结构和功能的研究,对于阐明肝癌发病机制以及研究新的肝癌诊断与治疗方法,具有重要的研究意义和应用价值.