定量蛋白质组学中的同位素标记技术

定量蛋白质组学的目的是对复杂的混合体系中所有的蛋白质进行鉴定,并对蛋白质的量及量的变化进行准确的测定,是当前系统生物科学研究的重要内容。近年来,由于质谱技术和生物信息学的进步,定量蛋白质组学在分析蛋白质组或亚蛋白质组方面已取得了令人瞩目的成就,但其最显著的成就应该归功于稳定同位素标记技术的应用。该技术使用针对某一类蛋白具有特异性的化学探针来标记目的蛋白质或肽段,同时化学探针要求含有用以精确定量的稳定同位素信号。在此基础上,实现了对表达的蛋白质差异和翻译后修饰的蛋白质差异进行精确定量分析。综述了在定量蛋白质组学中使用的各种同位素标记技术及其应用。     

基于质谱的定量蛋白质组学技术发展现状

蛋白质组定量分析技术是支撑蛋白质组学研究的关键技术之一,随着蛋白质组定量分析技术的发展,基于质谱的定量蛋白质组学已成为蛋白质组学研究的重要分支。蛋白质组学定量技术可分为非靶向定量和靶向定量两类,靶向定量技术有MRM和PRM模式,非靶向定量技术有非标记定量和体内外标记定量模式,目前使用最多的同位素标记试剂是i TRAQ和TMT。蛋白质组定量技术按数据采集模式还可分DDA和DIA两类。通过对国内外相关文献收集和分析,系统介绍了蛋白质组质谱定量技术的主要特点和发展现状,旨在为生命科学研究者更好地应用定量蛋白质组学技术提供帮助。     

细胞培养稳定同位素标记技术在蛋白质组学中的应用与进展

细胞培养稳定同位素标记技术（SILAC）是在细胞培养过程中,利用稳定同位素标记的氨基酸结合质谱技术,对蛋白表达进行定量分析的一种新技术。它不仅可以对蛋白质进行定性分析,还可通过质谱图上一对轻-重稳定同位素峰的比例来反映对应蛋白在不同状态下的表达水平,实现对蛋白质的精确定量。SILAC结合质谱技术在定量蛋白质组学中发挥了巨大的作用,其应用范围从细胞系扩展到亚细胞器、组织与动物整体水平,具体的应用策略也在不断完善发展。我们总结评述了SILAC技术在差异表达蛋白质组、蛋白质翻译后修饰、药物蛋白质组和蛋白质相互作用等方面的应用与进展。     

同位素稀释法在绝对定量蛋白质组中的研究进展

绝对定量蛋白质组是指基于蛋白质组学方法对细胞、组织或体液中的蛋白质进行绝对量或浓度测定．目前,常用的绝对定量方法主要有基于同位素稀释法的蛋白质组学绝对定量方法和基于质谱数据统计分析的非标记方法．基于同位素稀释法的绝对定量方法是用已知量的同位素标记物对与其混合的样本蛋白质浓度进行测定．常见的同位素标记物包括：由AQUA法、QconCAT法产生的特异性水解肽段,由PSAQ法、Absolute SILAC法产生的标记蛋白和由PrESTs-SILAC法产生的蛋白抗原表位标签．由于同位素稀释法可以对蛋白质进行准确和精确定量,对于临床疾病的诊断和治疗具有明显的现实意义．本文对同位素稀释法在绝对定量蛋白质组中的研究进展及其优缺点和最新应用进行了评述．     

植物蛋白质组学研究若干重要进展

植物蛋白质组学近年来正从定性向精确定量蛋白质组学的方向发展。国际上近两年发表的约160篇研究论文报道了利用不断改进的双向电泳结合生物质谱技术、多维蛋白质鉴定技术, 以及包括双向荧光差异凝胶电泳、15N体内代谢标记、同位素标记的亲和标签、同位素标记相对和绝对定量等在内的第2代蛋白质组学技术, 对植物组织(器官)与细胞器、植物发育过程和植物响应环境胁迫的蛋白质组特征, 以及植物蛋白质翻译后修饰和蛋白质相互作用等方面的研究成果。该文对上述报道进行总结, 综述了2007年以来植物蛋白质组学若干重要问题研究的新进展。     

植物蛋白质组学研究若干重要进展

植物蛋白质组学近年来正从定性向精确定量蛋白质组学的方向发展。国际上近两年发表的约160篇研究论文报道了利用不断改进的双向电泳结合生物质谱技术、多维蛋白质鉴定技术,以及包括双向荧光差异凝胶电泳、幅N体内代谢标记、同位素标记的亲和标签、同位素标记相对和绝对定量等在内的第2代蛋白质组学技术,对植物组织（器官）与细胞器、植物发育过程和植物响应环境胁迫的蛋白质组特征,以及植物蛋白质翻译后修饰和蛋白质相互作用等方面的研究成果。该文对上述报道进行总结,综述了2007年以来植物蛋白质组学若干重要问题研究的新进展。     

蛋白质组研究新前沿：定量蛋白质组学

在过去几年里,蛋白质组研究取得了令人鼓舞的进展,2DE-MS途径的自动化,多维色谱整合串联质谱的使用,弥补了一些用双向凝胶电泳分离蛋白质的技术缺陷;从稳定同位素标记到ICAT战略的提出,为准确定量在细胞或组织中发挥重要调节功能的低丰度蛋白质提供了一个较为理想的方法。同时,蛋白质芯片技术的不断发展,也极大的丰富了定量蛋白质组学的研究。就定量蛋白质组学及其相关技术研究进展作一简要综述。     

同位素标记相对和绝对定量技术研究进展

定量蛋白质组学是蛋白质研究的前沿学科。目前常用的定量蛋白质组学研究技术有荧光差异凝胶电泳（DIGE）、同位素亲和标记（ICAT）等。同位素标记相对和绝对定量（iTRAQ）技术是近年来最新开发的一种新的蛋白质组学定量研究技术。结合非凝胶串联质谱技术,该技术可对复杂样本、细胞器、细胞裂解液等样本进行相对和绝对定量研究,具有较好的定量效果、较高的重复性,并可对多达四种不同样本同时进行定量分析。本文对 iTRAQ 技术的原理、实验方法及应用进展进行了综述。     

基于电感耦合等离子体质谱的蛋白质定量技术研究进展

综述了ICP-MS法应用于蛋白质定量技术方面的研究进展.蛋白质定量研究已成为蛋白质组学研究领域的热点,它是解析生物体蛋白质功能的重要途径.基于同位素标记和生物质谱分析技术是蛋白质定量最常用的方法之一,近年来,随着质谱技术的发展,电感耦合等离子体质谱(ICP-MS)技术成为元素测量的重要手段,这使其在蛋白质定量中具一定的应用前景.     

定量蛋白质组同位素标记技术及应用

定量蛋白质组学是对蛋白质组进行精确的定量和鉴定的学科,突破了传统蛋白质组研究集中于对蛋白质的分离和鉴定,着重于定性定量解析细胞蛋白质的动态变化信息,更真实地反映了细胞功能、过程机制等综合信息。以同位素为内标的质谱分析新技术的提出,显示出可同时自动鉴定和精确定量的能力,代表了目前定量蛋白质组研究的主要发展方向。对近年来定量蛋白质组学同位素标记技术和应用研究所取得的重要进展以及最新的发展动态进行了综述。     

Quantitative Proteomics Employing Primary Amine Affinity Tags

A proteomics-based method using stable isotope labeling to assess the relative abundance of peptides or proteins is described. Bradykinin and carbonic anhydrase were labeled with sulfosuccinimidyl-2-(biotinamido) ethyl-1,3-dithiopropionate, a membrane impermeant reagent that is reactive with primary amines. Specificity of the label to primary amines was demonstrated using tandem mass spectrometry. Also, relative quantitation was achieved by secondary labeling with natural isotopic abundance and stable isotope-labeled methyl iodide. We believe this to be an effective stable isotope-labeling method for quantitative proteomics.     

Soluble polymer-based isotopic labeling (SoPIL): a new strategy to discover protein biomarkers?

Much attention has been given to protein biomarker discovery in the field of proteomics in the past few years. Proteomic strategies for biomarker discovery normally include the identification of proteins that alter during the progression of a particular disease state in high throughput. To perform these studies requires the ability to measure changes of low-abundance proteins in highly complex mixtures from different biological states. Soluble polymer-based isotope labeling (SoPIL) is a new proteomics strategy that targets specific classes of proteins for isotopic labeling, efficient isolation and accurate quantitation by mass spectrometry. The method exploits the features of homogenous solution-phase reaction, simple solid-phase extraction and characteristic cell-permeable nanoparticles. Recent applications demonstrate that the SoPIL reagents are ideal for quantitative proteomics and phosphoproteomics, and could have the potential to discover disease markers in the most physiologically relevant settings.     

Soluble polymer-based isotopic labeling (SoPIL): a new strategy to discover protein biomarkers?

Much attention has been given to protein biomarker discovery in the field of proteomics in the past few years. Proteomic strategies for biomarker discovery normally include the identification of proteins that alter during the progression of a particular disease state in high throughput. To perform these studies requires the ability to measure changes of low-abundance proteins in highly complex mixtures from different biological states. Soluble polymer-based isotope labeling (SoPIL) is a new proteomics strategy that targets specific classes of proteins for isotopic labeling, efficient isolation and accurate quantitation by mass spectrometry. The method exploits the features of homogenous solution-phase reaction, simple solid-phase extraction and characteristic cell-permeable nanoparticles. Recent applications demonstrate that the SoPIL reagents are ideal for quantitative proteomics and phosphoproteomics, and could have the potential to discover disease markers in the most physiologically relevant settings.     

Advances in quantitative proteomics via stable isotope tagging and mass spectrometry

The high-throughput identification and accurate quantification of proteins are essential components of proteomic strategies for studying cellular functions and processes. Techniques that are largely based on stable isotope protein or peptide labeling and automated tandem mass spectrometry are increasingly being applied in quantitative proteomic studies. Over the past year, significant progress has been made toward improving and diversifying these technologies with respect to the methods for stable isotope labeling, process automation and data processing and analysis. Advances in stable isotope protein labeling and recent biological studies that used stable isotope based quantitative proteomics techniques are reviewed.     

Heat-shock response in Arabidopsis thaliana explored by multiplexed quantitative proteomics using differential metabolic labeling

We have developed a general method for multiplexed quantitative proteomics using differential metabolic stable isotope labeling and mass spectrometry. The method was successfully used to study the dynamics of heat-shock response in Arabidopsis thaliana. A number of known heat-shock proteins were confirmed, and some proteins not previously associated with heat shock were discovered. The method is applicable in stable isotope labeling and allows for high degrees of multiplexing.     

Mass Spectrometry-Based Approaches Toward Absolute Quantitative Proteomics

Mass spectrometry has served as a major tool for the discipline of proteomics to catalogue proteins in an unprecedented scale. With chemical and metabolic techniques for stable isotope labeling developed over the past decade, it is now routinely used as a method for relative quantification to provide valuable information on alteration of protein abundance in a proteome-wide scale. More recently, absolute or stoichiometric quantification of proteome is becoming feasible, in particular, with the development of strategies with isotope-labeled standards composed of concatenated peptides. On the other hand, remarkable progress has been also made in label-free quantification methods based on the number of identified peptides. Here we review these mass spectrometry-based approaches for absolute quantification of proteome and discuss their implications.Key Words: Quantitative proteomics, mass spectrometry, absolute quantification, stable isotope labeling, label-free.     

Characterization of global yeast quantitative proteome data generated from the wild-type and glucose repression saccharomyces cerevisiae strains: the comparison of two quantitative methods

The quantitative proteomic analysis of complex protein mixtures is emerging as a technically challenging but viable systems-level approach for studying cellular function. This study presents a large-scale comparative analysis of protein abundances from yeast protein lysates derived from both wild-type yeast and yeast strains lacking key components of the Snf1 kinase complex. Four different strains were grown under well-controlled chemostat conditions. Multidimensional protein identification technology followed by quantitation using either spectral counting or stable isotope labeling approaches was used to identify relative changes in the protein expression levels between the strains. A total of 2388 proteins were relatively quantified, and more than 350 proteins were found to have significantly different expression levels between the two strains of comparison when using the stable isotope labeling strategy. The stable isotope labeling based quantitative approach was found to be highly reproducible among biological replicates when complex protein mixtures containing small expression changes were analyzed. Where poor correlation between stable isotope labeling and spectral counting was found, the major reason behind the discrepancy was the lack of reproducible sampling for proteins with low spectral counts. The functional categorization of the relative protein expression differences that occur in Snf1-deficient strains uncovers a wide range of biological processes regulated by this important cellular kinase.     

Quantitative analysis of SILAC data sets using spectral counting

We report a new quantitative proteomics approach that combines the best aspects of stable isotope labeling of amino acids in cell culture (SILAC) labeling and spectral counting. The SILAC peptide count ratio analysis (SPeCtRA, http://proteomics.mcw.edu/visualize ) method relies on MS² spectra rather than ion chromatograms for quantitation and therefore does not require the use of high mass accuracy mass spectrometers. The inclusion of a stable isotope label allows the samples to be combined before sample preparation and analysis, thus avoiding many of the sources of variability that can plague spectral counting. To validate the SPeCtRA method, we have analyzed samples constructed with known ratios of protein abundance. Finally, we used SPeCtRA to compare endothelial cell protein abundances between high (20 mM) and low (11 mM) glucose culture conditions. Our results demonstrate that SPeCtRA is a protein quantification technique that is accurate and sensitive as well as easy to automate and apply to high‐throughput analysis of complex biological samples.