2010全国质谱大会大会报告（四）

中国科学院大连化学物理研究所 许国旺研究员

　　来自中国科学院大连化学物理研究所的许国旺研究员做了题为“液相色谱-质谱用于代谢标志物的发现和鉴定”的报告。许老师提出，现在是一个组学的时代，代谢组学作为最主要的组学之一，目前在疾病研究、药物研发及职务和微生物等领域均得到重视。

　　代谢组学是研究小分子（相对分子质量小于1, 000）一个十分有用的工具，它以组织、体液或细胞为研究对象。一般来说，代谢组学的研究包括样品采集、预处理、代谢组数据采集、多变量数据分析、标志物发现和识别及最终的生物解释几方面。由于缺乏数据库样本及标样，代谢标志物的识别是研究的一个瓶颈。

　　许老师在报告中，讲述了基于色谱-质谱联用技术的集成识别策略，包括多变量数据分析、精确分子量测定、质谱碎片裂解规律、色谱保留规律、馏分微制备、亲和色谱、酶解等。并列举了药物作用机理和疾病标志物的代谢组学研究作为实例阐述了这一集成策略。

Wisconsin-Madison（威斯康星-麦迪逊）大学 Li,Lingjun(李灵军)教授

　　来自Wisconsin-Madison（威斯康星-麦迪逊）大学的Li,Lingjun(李灵军)教授，做了题为“Probing Neuronal Communication via Novel Mass Spectral Strategies”（用新型质谱技术探索神经通讯）的报告。她首先介绍了神经肽在细胞间通讯中至关重要的作用，这些聚合多肽在化学信使调节，和在神经电路中测定它们的功能中具有重要作用。甲壳动物具有较简单和已被充分研究的神经系统，可作为很好的模型系统来发展分析方法，并观测神经肽丰富的全部细节是如何来精细调节神经电路，并在细胞和神经网络水平产生多种输出。使用高灵敏度的基于质谱的多肽图和从头测序方法，发现了大量的新型多肽，并发现即使一个相对简单的神经元网络，同样包含了未被预期的丰富多样的神经肽。另外，质谱成像技术和活体微透析取样工具，可史无前例地对神经肽分布和分泌的细节进行追踪。对于完成对生物活性的神经肽的功能发现的目标，发展了建立在同位素甲醛标记和多同位素标记（N,N-二甲基亮氨酸）的新型定量技术基础上的方法，可对不同生理条件下的神经肽组进行区分显示。李教授介绍了神经肽在摄食行为和环境压力下的调节。总而言之，这种多肽组学结合生理学的研究，有助于阐释在调节神经网络可塑性方面，神经肽扮演的功能。以下是英文摘要：

　　Neuropeptides make up the largest and the most complex signaling molecules used in intercellular communication. Because of critical roles that these polypeptides play in the regulation of chemical messengers and determine their functions in the neural circuitry. The simpler and well-characterized crustacean nervous system provides an excellent model system to facilitate analytical method development and to investigate how a rich repertoire of neuropeptides can fine tune a well-defined neural circuit that produces multiple outputs at the cellular and network levels. Using a highly sensitive mass spectrometry-based peptide profiling and de novo sequencing strategy, a large number of novel peptides have been discovered, revealing that even a relatively simple neural network contains an unexpectedly-rich diversity of neuropeptides. Furthermore, both mass spectrometric imaging techniques and in vivo microdialysis sampling tools have been implemented to follow neuropeptide distribution and secretion in unprecedented details. Towards the goal of functional discovery of bioactive neuropeptides, novel quantitative schemes based on isotopic formaldehyde labeling and multiplexed isobaric labeling based on N.N-dimethylated leucine have been developed to produce differential display of neuropeptidomes under different physiological. Example of neuropeptide regulation of feeding behavior and environmental stress will be described in this presentation. Collectively, these combined peptidomic and physiological studies will help to elucidate the function roles that neuropeptides play in regulating neural network plasticity.

加拿大Alberta大学 Le,Chris（乐晓春）教授

　　来自加拿大Alberta大学的Le,Chris（乐晓春）教授，做了题为“Mass Spectromety and Affinty Chromatography Techniques for Studying Arsenic-binding Proteins in Human Cells”（在研究人类细胞中砷结合蛋白中的质谱和亲和色谱技术）的报告。砷中毒对于疾病、环境等的影响众所周知，但砷中毒的机理还不清楚，可能是三价砷结合了蛋白的硫基团，因此改变了蛋白的构象抑制了蛋白功能。为研究与蛋白作用的砷，课题组开发了一种亲和选择技术并与串联质谱联用，从大量的细胞蛋白中选择和鉴定特定的与砷结合的蛋白。受控实验使用包含游离半胱氨酸或非活性半胱氨酸的蛋白，显示砷亲和柱特异捕获游离的半胱氨酸。该方法被应用到牛胆绿素还原酶B、A549人肺癌细胞亚细胞器组分等研究中。使用亲和色谱-串联质谱方法鉴定大量的砷结合蛋白，因为其重要的生物功能引起科学家的关注。实验证实砷可以结合细胞提取物的蛋白质，而砷如何影响生物系统中的蛋白功能，需要继续研究活体细胞中砷和蛋白的相互作用才能确认。以下是英文摘要：

　　 Arsenic is one of the most important environmental agents in causing chronic human disease. Elevated levels of arsenic drinking water may affect >100 million people around the world .A wide variety of adverse health effects, most seriously, cancers of bladder, lung, urinary tract, and skin, have been attributed to chronic exposure to arsenic . However, the biochemical mechanisms responsible for these effects caused by arsenic remain unclear ,but may be mediated by the binding of trivalent arsenicals to thiol groups in proteins, thereby changing the conformation of these proteins and inhibiting their functions. If some of the affected proteins are responsible for cellular repair of DNA damage, for example, the inhibition of these proteins could lead to carcinogenesis.

　　 To study interaction of arsenic with proteins, we have developed an affinity selection technique, coupled with mass spectrometry, to select and identify specific arsenic-binding proteins from a large pool of cellular proteins. Controlled experiments using proteins either containing free cysteine(s) or inactive cysteine showed that the arsenic affinity column specifically captured the proteins containing free cysteine(s) available to bind tu arsenic .The technique was able to capture and identify trace amounts of bovine biliverdin reductase B present as a minor impurty in the commercial preparation of carbonic anhydrase II ,demonstrate the ability to identify arsenic-binding proteins in the presence of a large excess of non-specific proteins. application of the technique to the analysis of subcellular fractions of A549 human lung carcinoma cells identified 50 proteins in the analysis of subcellular fraction ,and 24 proteins in the membrane/ organelle fraction that could bind to arsenic .This added substantially to the current list of only a few known arsenic-binding proteins.

　　 A mumber of arsenic-binding proteins identified using the affinity chromatography tandem mass spectrometry approach were of particular interest because of their important biological functions .For example ,DNA-dependent protein kinase, ATP-dependent helicase II (Ku 70),and topoismerase 2 alpha , are involved in DNA repair and maintaining genome stability .several other proteins modulate the redox status of cells , e.g . peroxiredoxin-1 and thioredoxin ,and apoptosis ,e.g.,lamin A and heat shock cognate protein .this work shows that arsenic can bind to these proteins in cells extracts。How arsenic affects the function of these proteins in biological systems will have to be confirmed by studying arsenic interaction with proteins in living cells.

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台湾Soochow大学化学系 Ming-Ren Fuh(傅明仁)教授

　　来自台湾Soochow大学化学系的Ming-Ren Fuh(傅明仁)教授，做了题为“Microfluidic chip-based nano-liquid chromatography-tandem mass spectrometry for bioanalysis”（基于微流芯片的纳升液相色谱-串联质谱用于生物分析）的报告。在报告中，傅教授先介绍了基于微流控芯片的商品化产品，这些纳升级液相系统已经显著提高了纳升级液相分析的稳定性。基于芯片的纳升级液相-串联质谱已被证明可提高液相分离的分辨率，并增强质谱检测的灵敏度。傅教授介绍了课题组应用基于芯片的纳升级液相-串联质谱分析用于药物代谢物、生物标志物和临床诊断的生物体液的神经递质的结果，给出了包括重现性、检出限、线性和精密度等分析性能；还讨论了分析人尿的基质效应和离子抑制效应，展示了基于芯片的微流控纳升级液相-串联质谱在临床诊断中的应用能力。以下是英文摘要：

　　Recent commercially available microfluidic chip-based nano-liquid chromatography system has greatly improved the robustness of nano-LC analysis. Chip-based nano-LC-tandem mass spectrometry(nano-LC-tandem MS) has been proven to enhance the resolution of LC separation and the sensitivity of MS detection. In this paper, we will discuss the utilization of chip-based nano-LC-tandem MS for the analyses of drug metabolite (7-aminoflunitrazepam),biomarker(8-isoprostane) and neurotransmitters in biological fluids for clinical diagnosis. The analytical performance (reproducibility, detection limit, linearity and precision) for various analytical compounds will be presented. In addition, matrix effect and ion suppression effect of human urine will be discussed. The applicability of microfluidic chip-based nano-LC-tandem MS for clinical diagnosis will be demonstrated.

中国科学院北京基因组研究所 刘斯奇研究员

　　来自中国科学院北京基因组研究所的刘斯奇研究员做了题为“Protein biomarker in clinical assay using mass spectrometry: Possibility and difficulities（质谱在研究蛋白质生物标记物临床鉴定中的应用：可能性和难点）”刘老师总结了近段时间阅读的文献，与大家分享。蛋白质组带有基因组和代谢组所不具有的特性，如表达的动态性和空间性、后反应修饰等。

　　研究蛋白质生物标记物的优点在于，样品收集相对简单，来自于体液；大多数蛋白生物标记物均是翻译后修饰；蛋白直接与病理性功能相关。因此，对蛋白质组的研究是热点。研究成果有ELISA、蛋白活性和蛋白芯片等。其中，刘老师重点讲了ELISA。

　　目前研究的方法可以鉴定1000多种蛋白质，但被FDA批准的鉴定方法中没有一个是用蛋白质组学的方法。因此，在发现新的蛋白待测物方面，蛋白质组学的发展并没有为生物标记物的发现做出贡献。刘老师指出，在临床化学中，亟需一种蛋白诊断的方法。从定性到定量、从发现到目标化将成为今后蛋白质组学的两大研究趋势。

台湾国立清华大学生物工程和环境科学系 Yuh-chang Sun(孙毓章)教授

　　来自台湾国立清华大学生物工程和环境科学系的Yuh-chang Sun(孙毓章)教授，做了题为“Development of photocatalyst-based ICP-MS coupling techniques for determination of trace elements and their species”（研发基于光催化的ICP-MS联用技术，测定痕量元素及其形态）的报告。课题组研究了对超痕量（亚ug/L）金属元素及其形态分析的方法，使用前处理手段、色谱分离和ICP-MS联用，可克服生物或环境分析中的背景基质干扰并提高灵敏度。他们开发了几种联用系统，使用了光氧化还原纳米二氧化钛的接口装置，把包含无机和有机金属的各种形态均转化为利于ICP-MS分析的气相产物，证明该方法对于分析环境和生物背景下的痕量元素及其形态是有效的。以下是英文摘要：

　　It is well known that the speciation, or chemical form, of metal governs its fate, toxicity, mobility, and bioavailability in environmental and biological systems. To assess these chemical properties and to accurately gauge their impact on human health and the environment, metal need to be characterized at the atomic level. To attain new information about environmental and biological effects of trace elements, new methodologies or modify conventional analytical methods is deemed as vital factor for the progress of bio -and environmental -studies. In view of the limitation on the analytical capability of single instrumental technique, analytical chemists can seldom rely on a single instrumental technique to analyzed a sample with complicated matrix and analyte species with a variety of phsico-chemical form. It is thus necessary to develop a technique which can fulfill ultratrace analyses of metal species down to the sub-μg/L concentration range in complicated samples.

　　Accordingly, the most important features of an analytical tool suitable for meeting the requirement of modern bio-analytical works are shorter temporal resolution, good selectivity and high sensitivity. For ultratrace elements measurements, ICP coupled with Mass Spectrometry (ICP-MS) has been considered as first priority option. Although the analytical sensitivity has been significantly improved by the technical advances in ICP-MS, instrumental limitations, such as difficulties in differentiating elemental species and removing matrix interferences caused by the concomitant salt, still remain in advanced analytical technologies. To satisfy the analytical requirements, the potency of hyphenating analytical separation techniques to mass spectrometers has been recognized. Basically, according to Histchfeld, the advantages brought about by coupling techniques are increasing the differentiating and separating power of analytical methods and synergism between methods. However,the design of the analytical system is difficult, owing to the complex composition of the real-world sample, the diversity of physicochemical forms of the element, their lability and low concentrations. For overcoming the abovementioned problems, attempts to couple ICP-MS with various types of chromatography for separation, as well as on-line sample pretreatment techniques for signal enhancement and matrix removal have been made. To expand the analytical capability, in this study, we developed several hyphenated systems by integrating the alternative photo-redox characteristic of nano-TiO2 into the interfacing device to convert both inorganic and organic metal-containing species to gaseous products that are favor for ICP-MS determination. Based on our experimental results, this presentation will describe the studied hyphenated methods which have been proven feasible for the analyses of trace elements and their chemical species in environmental and biological systems.

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中国科学院上海有机化学研究所 郭寅龙研究员

　　来自中国科学院上海有机化学研究所的郭寅龙研究员做了题为“基于MALDI-FTMS 的酶活检测方法研究”的报告。郭老师介绍，MALDI离子化方式具有以下优势：MALDI-MS可耐高浓度盐、缓冲液和其他非挥发性成分，具有较大的样品处理能力和样品分析速度。傅立叶变化质谱检测器又具有以下优势：分辨率高、质量范围宽、准确度高、灵敏度不受分辨率影响；不需要外部设备，用软件执行就可以实现多级质谱串联；与软电离方式(ESI和MSLDI)相容性好。

　　郭老师介绍了，实验中建立的简单快速的牛奶中β-内酰胺酶的MALDI-MS检测方法，即通过检测β-内酰胺酶催化的酶反应来反映β-内酰胺酶的活性，采用高速离心的方法可以减少牛奶中干扰小分子检出的物质。傅立叶变换质谱的高分辨和高质量准确性使其可以排除复杂的样品基质干扰，该方法可以扩展用于更为复杂的体系。质谱仪器的高选择性，可以在检测β-内酰胺酶的同时，对牛奶样本中存在的其他残留进行检测。

美国哥伦比亚Missouri医学院 Gu, Zezong(顾泽宗)教授

　　来自美国哥伦比亚Missouri医学院的Gu, Zezong(顾泽宗)教授，做了题为“Quantitative Profiling of S-Nitrosylated Proteins in Parkinson’s Disease Paradigms with the Effects of Botanical Phenolics”（在植物酚效应下定量研究帕金森病病例中的S-亚硝基化蛋白）的报告。在报告中，顾教授先介绍了跟衰老相关的神经疾病如帕金森病（PD）的起因，是由自由基活性的氮氧化物（RNS/ROS）引起的，会导致神经细胞死亡，和发病机制相关。自由基氮氧化物（NO）是一种广泛调节从发展到疾病的细胞功能的信号分子。课题组研究了其机理，并开发了基于凝胶的蛋白质组学方法，命名为NitroDIGE，在全局范围去定量研究蛋白S-nitrosylation（S-亚硝基化）。应用该方法，课题组鉴定了以帕金森病的体内和体外模型的S-亚硝基化蛋白的一个子集，并测定了在细胞帕金森病模型中是否S-亚硝基化蛋白会被不同的植物酚类物质（如来源于绿茶的儿茶素、来源于胡黄连的夹竹桃麻素等）的调控。NitraoDIGE方法显示用植物化合物治疗后，能够减少过量的S-亚硝基化蛋白，表明植物酚类物质能够有效减轻硝化压力和帕金森病相关的困扰。以下是英文摘要：

　　A convergent feature for most aging-related neurological diseases, such as Parkinson’s Disease (PD), is excessive generation of free radicals-reactive nitrogen and oxygen species (RNS/ROS), which can contribute to neuronal cell death and link to the disease pathogenesis. Free radical nitric oxide (NO) is a signaling molecule involving in the regulation of a wide range of cellular functions from development to disease. Emerging evidence suggests that nitrosative stress due to NO over-production induces post-translation modifications of protein cysteine and modulates protein enzymatic activity in cells. S-Nitrosylation, the covalent adduction of NO to specific protein cysteine thiol, is considered as a predominant, redox-based prototypical mechanism for cell signaling .Previously, endogenous protein S-nitrosylation was detected by the biotin switch assay. Taking the advantages of both biotin switch assay and differential in-gel electrophoresis (DIGE),we developed a gel-based proteomics method, named as NitroDIGE, to globally and quantitatively investigate protein S-nitrosylation. Using this method we identified a subset of S-nitrosylated proteins from both in vitro and in vivo models of Parkinsonism including pesticide rotenone-induced PD-models could be modulated by different botanical phenolic compounds, including epigallocatechin galllate(EGCC) from green tea, and apocynin from Picrorhiza kurrooa, a herbal plant grown in the Himalayan. The NitroDIGE results demonstrated that the treatment of botanical compounds could reduce excessive S-nitrosylated proteins in SH-SY5Y cells exposed to rotenone,indicating that these botanical phenolics could serve as effective scavengers to attenuate nitrosative stress and PD-relevant insults.

北京大学 刘虎威教授

　　来自北京大学的刘虎威教授做了题为“在线正反相二维液相色谱四级杆飞行时间质谱联用方法及其在大鼠腹膜表层脂质轮廓分析中的应用”的报告。报告中，刘教授介绍了有关动物体内磷脂的分析。与磷脂有关的疾病有动脉粥样硬化、糖尿病、肥胖证、帕金森综合症等。磷脂的分类中，极性的结构适合用正向色谱分离，长链的脂肪酸适用于反向色谱分离，只用一种色谱进行分离，达不到很好的效果。如果将正向与反向联用，可以提高分离效率。但是，正向色谱的流动相是有机相，而反向色谱的流动相是水相，从第一维向第二维切换的过程中容易造成堵塞，因此，改进接口技术是关键。

　　刘教授利用改进的接口技术并将将液相色谱四级杆飞行时间质谱联用，对于大鼠腹膜表层脂质进行分析，结果显示，检测到1万多个化合物，而之前用毛细管电泳与质谱联用的时，只检测到96个化合物，刘教授提出，复杂的数据处理仍是需要解决的问题。

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辉瑞-惠氏（Pfizer/Wyeth） Feng, Xidong（冯喜东）教授

　　来自辉瑞-惠氏（Pfizer/Wyeth）的Feng, Xidong（冯喜东）教授做了题为“Structure Elucidation of Natural Product Cyclic Peptides with Labile Side-Chain Modifications Using CID, IRMPD and ECD FTMS/MS（基于CID, IRMPD 和ECD FTMS/MS的侧链改性研究天然产物环肽的结构鉴定）”的报告。

　　冯教授在报告中介绍了，通过Multi-CHEF、SORI-CID、iRMPO和ECO实验以及基因交替的方法，使用FTMS/MS，用不稳定的侧链改性的方法阐明未知天然产物环肽的结构。结果表明，具有ppm检测精度的FTMS适合于研究不常见的氨基酸残基的序列。

加拿大Alberta大学实验室医学和病理学系分析和环境毒理室 Li,Xing-Fang教授

　　来自加拿大Alberta大学实验室医学和病理学系分析和环境毒理室的Li,Xing-Fang教授，做了题为“Mass Spectrometry Techniques for Discovery of Carcinogens in Drinking Water and Studies of Health Effects”（用质谱技术发现饮用水中的致癌原和对健康影响的研究）的报告。在报告中，李教授首先介绍了饮用水污染消毒中现存的一些问题。饮用水的微生物污染仍是全球范围内水引起的疾病的重要原因，而饮用水消毒中会引入消毒副产物（DBPs），是消毒剂（如氯和氯胺）和水中的天然有机物（如NOM）反应产生的。为了控制引用水质，在很多国家，如三卤代甲烷（THMs）和卤代乙酸（HAAs）的消毒副产物已被替代。流行病学的研究表明，饮用氯代的水会增加患膀胱癌的风险。然而，从过去30年积累的证据表明，已被调节的DBPs不是膀胱癌风险增加的原因，或在生殖研究中观察到其反作用。还有其它不明物毒性更大，会在更低水平上生成DBPs。为了应对饮用水安全在分析和生物分析方面的挑战，课题组发展了一系列液相色谱-串联质谱技术用于分析饮用水中超痕量的致病原。课题组发现了一些以前未知的DBPs，可能是膀胱癌的致病原，比如饮用水中的亚硝胺类、卤代苯醌、氯代phanazines。该报告举例了用串联质谱法对DBP-DNA结合的研究，可作为基因毒性测试的工具，有助于在立法中考虑DBPs的优先级。以下是英文摘要：

　　Microbial contamination of drinking water is still the major cause of water-borne disease affecting millions of people around the world. Disinfection of drinking water is the most effective public health measure to disinfect pathogens to eradicate water-borne diseases. However, disinfection of water unintentionally results in formation of disinfection byproducts (DBPs) from the reactions between disinfectants (e.g. chlorine and chloramines) and natural organic matters (NOM) in water. In order to control drinking water quality, surrogate DBPs such as several trihalomethanes (THMs) and haloacetic acids (HAAS) are currently regulated in the most countries. Epidemiological studies have shown potential association of drinking chlorinated water and increased risk of developing bladder cancer. However, accumulating evidence from past 30 years suggests that the regulated DBPs are not the cause of the increased bladder cancer risk or adverse reproductive effects that have been observed in population studies. Other unidentified, yet more toxic, DBPs may be produced at much lower levels. To address the analytical and bioanalytical challenges in drinking water safety, we have developed a set of liquid chromatography and tandem mass spectrometry techniques for ultra sensitive detection of carcinogens in water. We have discovered some previously unknown DBPs that are likely bladder carcinogens, such as nitrosamines, haloquinones, and chloro-phanazines in drinking water. In the present study, we report tandem mass spectrometry study of DBP-DNA binding as a tool for genotoxicity testing to assist prioritization of DBPs for regulatory consideration.

美国普渡大学癌症研究中心 Tao,Andy(陶纬国)教授

　　来自美国普渡大学癌症研究中心的Tao,Andy(陶纬国)教授，做了题为“In-Depth Phosphoproteome Analyses Using PolyMAC”（用PolyMAC深入分析磷酸化蛋白质组）的报告。在报告中，陶教授介绍了课题组发展的一种磷酸化肽的富集方法，称为PolyMAC（基于聚合物的金属离子亲和富集）。该试剂的核心部分是水溶性并容易从聚合物中获得的。课题组对PolyMAC和TiO2方法在专一性、重现性和灵敏度方面进行了比较；并比较了用几种金属离子功能化的PolyMAC试剂。富集后的磷酸化肽用纳升级液相色谱-串联质谱联用（nLC-MS/MS）方法分析。液相为Eksigent公司的ultra 2D LC系统，质谱用LTQ Orbitrap velos，数据用Proteome Discovery软件的SEQUEST方法检索。结果显示，仅使用50 ug的溶胞物，一次实验，PolyMAC富集后即可鉴定1000个磷酸化肽，具有95％以上的选择性。总体上，PolyMAC方法显示了优秀的选择性，出众的回收率和高重现性，是今日最有效的磷酸化肽富集技术。课题组还利用该方法研究了乳腺癌体系。以下是英文摘要：

　　Protein phosphorylation plays critical roles in the regulation of many cellular functions. Analysis of phosphoproteomes by mass spectrometry depends on an efficient method to enrich phosphopeptides from complex mixtures. The current prevailing enrichment methods lack required efficiency and reproducibility due to complex sample conditions. Here, we utilize a novel soluble nanopolymer-based phosphopeptide enrichment approach termed PolyMAC (Polymer-based Metal ion Affinity Capture) for in-depth phosphoproteome analysis.

　　The central piece of PolyMAC reagents lies in a water soluble and highly accessible polymer support. PolyMAC reagents are synthesized from polyamidoamine (PAMAM) dendrimers functionalized with metal ions to specifically capture O-phosphorylated peptides through bidentate chelation chemistry. An extensive comparison was made between PolyMAC reagents and the TiO2 method, in terms of the specificity, reproducibility and sensitivity. We also compared different types of PolyMAC reagents functionalized with several metal ions. The enriched phosphopeptides were analyzed by nanoflow liquid chromatography tandem mass spectrometry (Nlc-MS/MS). The MS spectra were acquired on an Eksigent ultra 2D LC system that is coupled to hybrid liner ion trap orbitrap mass spectrometer (LTQ Orbitrap velos, Thermo Fisher). Data were searched using the SEQUESTTM algorithm within the Proteome Discoverer software. Using only 50 ug of total cell lysate, PolyMAC enrichment has led to the identification of over 1000 phosphopeptides with over 95% selectivity in a single run. Overall, the PolyMAC method demonstrated excellent selectivity, outstanding recovery yield and high reproducibility, thus rendering it one of the most effective phosphopeptide isolation techniques to date.

　　The PolyMAC enrichment approach has been applied to examine the differences in signaling pathways in breast cancer cell lines modulated by a tumor suppressor,spleen tyrosine kinase (Syk). MDA-MB-231 human breast cancer cell line was transfected with a tetracycline-inducible Syk vector. Proteins from cells with or without Syk induction were processed and phosphotyrosine peptides were enriched using the combination of pTyr peptide immunoprecipitation and PolyMAC to obtain the phosphorylation profiles. We identified 794 sites of tyrosine phosphorylation in malignant breast cancer cells,514 of which are dependent on the expression of Syk. Proteins with changes in pTyr phosphorylation were manually validated and a number of them confirmed through immunoprecipitation-Western blot experiments. They were mapped in a variety of major signaling networks including cell migration and apoptosis, therefore offering numerous leads to future breast cancer studies.

清华大学 林金明教授

　　来自清华大学的林金明教授做了题为“纸基电喷雾质谱常态离子源直接测定复杂样品”的报告。质谱是测定复杂样品的有效手段，能够提供待测物的分子信息。目前的质谱分析通常需要对复杂样品进行预处理和预分离，无法实现快速和高效分析。为解决复杂样品直接检测过程中的样品前处理难题，林教授的课题组提出了一种称为纸基电喷雾的新型常态离子源。将样品直接加载到三角形的色谱纸上，接通高压电后即可直接生成电喷雾，能够进行直接的质谱检测。

　　与Nano-ESI的对比实验表明，纸基电喷雾比Nano-ESI能保留更多的分子离子，其电离能力更软。计算表明，纸基电喷雾产生的分子离子具有的内能比Nano-ESI产生的分子离子内能低0.4电子伏左右，因此更适合生物分子样品的质谱分析。

　　这一离子源能够适用于大多数的化合物，包括小分子有机物、肽和蛋白质等。利用在纸上进行液体干燥后检测的方法还可以直接测定血样和尿样中的各种药物和代谢物。利用纸的采样能力能够直接分析固相表面的样品，测定快速，灵敏度高。将纸基电喷雾与便携式质谱仪联用，能够拓宽在非实验室环境下的复杂样品检测能力。最后，林教授指出，纸基电喷雾具体的机理还有待于进一步的实验证明。