免疫蛋白质组学技术筛选布鲁菌高免疫原性膜蛋白

目的建立布鲁菌免疫蛋白质组学方法,从羊布鲁菌膜蛋白中筛选免疫候选抗原。方法提取羊布鲁菌16M膜蛋白,进行双向电泳(2-DE)分离,分别用牛、羊布鲁菌感染的阳性血清进行Westernblot分析,筛选出的免疫显性蛋白点进行LC-MS/MS质谱鉴定,并进行生物信息学分析。结果筛选出56个免疫显性蛋白点,鉴定成功35个,其中有12个蛋白是能够被牛、羊2种血清共同识别的抗原。数据检索显示,这些蛋白主要涉及布鲁菌的能量代谢,蛋白质、氨基酸合成,脂肪酸代谢及糖和辅酶的合成等生物过程。结论利用免疫蛋白质组学技术成功筛选出羊布鲁菌高免疫原性膜蛋白,为布鲁菌亚单位疫苗的研制提供了大量的候选抗原。     

冰淇淋中益生菌冷冻胁迫致菌体损伤 机制研究进展

冰淇淋是优良的益生菌载体,但其加工中的老化、凝冻和硬化等阶段性降温至冷冻的过程,会造成益生菌生理损伤,导致益生菌活力下降,功能性变差。近年,有关冰淇淋中冷冻胁迫致益生菌的损伤,冰淇淋中益生菌活性的保护,以及组学技术推动下的菌株损伤相关代谢研究取得了一定进展,为研究影响冰淇淋中益生菌存活能力、菌体细胞膜特性及代谢酶活性,明确冰淇淋基质中益生菌冷冻胁迫损伤的分子机制,建立冰淇淋加工和贮藏过程中益生菌的保护策略提供了可能,也为未来改善益生菌冰淇淋的功效和品质提供科学依据。     

Peptide biomarkers as a way to determine meat authenticity

Meat fraud implies many illegal procedures affecting the composition of meat and meat products, something that is commonly done with the aim to increase profit. These practices need to be controlled by legal authorities by means of robust, accurate and sensitive methodologies capable to assure that fraudulent or accidental mislabelling does not arise. Common strategies traditionally used to assess meat authenticity have been based on methods such as chemometric analysis of a large set of data analysis, immunoassays or DNA analysis. The identification of peptide biomarkers specific of a particular meat species, tissue or ingredient by proteomic technologies constitutes an interesting and promising alternative to existing methodologies due to its high discriminating power, robustness and sensitivity. The possibility to develop standardized protein extraction protocols, together with the considerably higher resistance of peptide sequences to food processing as compared to DNA sequences, would overcome some of the limitations currently existing for quantitative determinations of highly processed food samples. The use of routine mass spectrometry equipment would make the technology suitable for control laboratories.     

创新的蛋白质组学质谱应用新技术——SWATH技术

AB SCIEX公司在2011年美国第59届质谱年会上新推出了SWATH（Sequential Windowed Acquisition of all Theoretical fragment ions,SWATH）采集技术,该技术是与苏黎世联邦理工学院Ruedi Aebersold博士及其团队共同开发的。SWATH采集模式为研究蛋白质组学的用户带来了创新的技术,科学家利用该技术可以在一次进样分析中即可获得复杂蛋白质组样品中每个肽段的数据。SWATH采集模式是AB SCIEX的MS/MSALL技术的延伸,此功能只能在TripleTOFTM5600系统上完成,作为对MRMAtlas的完美补充,为未来蛋白质组学研究提供了一种全新的工作流程,预计将产生令人震撼的蛋白质组学新发现。     

Proteome changes in the insoluble protein fraction of bovine Longissimus dorsi muscle as a result of low-voltage electrical stimulation

Changes induced by low-voltage electrical stimulation (ES; 0-95 V for 8 s; 95 V for 32 s) in the insoluble protein fraction of bovine longissimus dorsi (LD) muscle at 1 and 24h post-ES were investigated by proteomics. Protein abundance patterns from ten Norwegian Red (NRF) young bulls were compared, and significant changes due to ES were found by rotation test and partial least square (PLS) regression analyses. Five protein spots showed lower abundance in ES samples at both sampling times, and in addition, 10 proteins at 1 h post-ES and 13 proteins at 24 h post-ES changed significantly in abundance due to ES. Reduced abundance of full-length structural proteins in ES samples indicates an accelerated proteolysis due to ES. Moreover, increased abundance of small heat shock proteins indicates earlier initiation of stress responses due to ES. These findings provide a better understanding of the biochemical processes taking place as a result of ES during post mortem storage of meat.     

蛋白质组学研究及其在放射医学领域的应用

蛋白质组学是继基因组学之后的一个重要研究热点.近年来,蛋白质组研究技术已应用到多种生命科学领域中,但在放射医学领域的研究尚处于起步阶段.本文介绍了蛋白质组学的研究背景、进展、研究内容及技术方法,着重阐述了在放射医学领域中的应用.     

Early post-mortem sarcoplasmic proteome of porcine muscle related to protein oxidation

Oxidative deterioration or modifications of proteins which appear during meat storage and processes can result in the impairment of technological, sensorial and nutritional qualities. Improving the quality involves a better understanding of the biochemical mechanisms responsible for protein oxidation in meat. For that purpose, an analysis was conducted to investigate the relationships between the early post-mortem sarcoplasmic proteome, which contains the majority of enzymes involved in the oxidative process, and protein oxidation generated during meat storage and cooking. This study was performed in Longissimus lumborum pig muscle. In order to have sufficient variability in the proteome and in the meat oxidation level, five groups of 10 animals issued from two different breeds and raised in three different rearing systems were analysed. Protein oxidation was estimated by the measurement of carbonyl groups after 1 and 4 days of refrigerated storage, and after 100 °C experimental cooking of the 4 days aged meat. Significant correlations (p < 0.05) were observed between the level of carbonyl groups and the intensities of 104 spots of the 2D electrophoresis, out of which 52 were clearly identified. The possible involvement of some proteins in the muscle oxidative stress leading to protein oxidation is discussed.     

Covering with Ellipses

We address the problem of how to cover a set of required points by a small number of axis-parallel ellipses that avoid a second set of forbidden points. We study geometric properties of such covers and present an efficient randomized approximation algorithm for the cover construction. This question is motivated by a special pattern recognition task where one has to identify ellipse-shaped protein spots in two-dimensional electrophoresis images.     

Proteomic analysis of processing by-products from canned and fresh tuna: Identification of potentially functional food proteins

Proteomic approaches have been used to identify the main proteins present in processing by-products generated by the canning tuna-industry, as well as in by-products derived from filleting of skeletal red muscle of fresh tuna. Following fractionation by using an ammonium sulphate precipitation method, three proteins (tropomyosin, haemoglobin and the stress-shock protein ubiquitin) were identified in the highly heterogeneous and heat-treated material discarded by the canning-industry. Additionally, this fractionation method was successful to obtain tropomyosin of high purity from the heterogeneous starting material. By-products from skeletal red muscle of fresh tuna were efficiently fractionated to sarcoplasmic and myofibrillar fractions, prior to the identification based mainly on the combined searching of the peptide mass fingerprint (MALDI–TOF) and peptide fragment fingerprinting (MALDI LIFT-TOF/TOF) spectra of fifteen bands separated by 1D SDS–PAGE. Thus, the sarcoplasmic fraction contained myoglobin and several enzymes that are essential for efficient energy production, whereas the myofibrillar fraction had important contractile proteins, such as actin, tropomyosin, myosin or an isoform of the enzyme creatine kinase. Application of proteomic technologies has revealed new knowledge on the composition of important by-products from tuna species, enabling a better evaluation of their potential applications.     

Proteomic analysis of the gene DR1709 mutant in Deinococcus radiodurans

DR1709 is a predicted Mn~(2+) transporter in Deinococcus radiodurans(D.radiodurans). The mensuration method to evaluate protein viability with two-dimensional electrophoresis in D.radiodurans and the mutants was established in this study. The results showed that after DR1709 was disrupted, the expressions of DR1120(acetokinase), DR1691 (heat shock protein), DR1485 (putative lipase), DR2095 (putative c-type cytochrome) and other three hypothetical proteins (DR0124, DR0047 and DR2474) were repressed. However the expression of DR1794 (putative nosX) was induced. Phenomena above suggested that the increased radiation-sensitivity of the mutant cells may be attributed to not only the protection of gene DR1709, but also the proteins' different expressions between the wild type and the mutant might also play important roles in protecting D.radiodurans from irradiation.Although DR2095 was a homologue of c-type cytochrome, it has no realitic functions.