腺苷酸环化酶毒素在无细胞百日咳疫苗中的免疫保护效果评价

目的 利用小鼠百日咳感染模型评估在无细胞百日咳疫苗中加入腺苷酸环化酶毒素的C端结构域(RTX751),能否提升无细胞百日咳疫苗的免疫保护效果.方法 ①用腺苷酸环化酶毒素的C端结构域与百日咳毒素(pertussis toxin,PT)、丝状血凝素(filamentous hemagglutinin,FHA)、百日咳黏附素...     

基于生物质谱的胶原蛋白定量检测方法

本研究旨在建立一种基于特征多肽的胶原定量检测方法,通过序列比对的方法筛选胶原蛋白特征多肽,利用胰蛋白酶将牛Ⅰ型胶原蛋白标准品进行酶解,采用液质联用技术(HPLC-MS)对特征多肽进行检测,建立特征多肽丰度与胶原蛋白浓度对应关系并用于实际样品分析。结果表明,牛Ⅰ型胶原蛋白中检测出6种特征多肽,其中多肽GEAGPSGPAGPTGAR由于其丰度高且二级质谱稳定适合作为定量检测的特征多肽,多肽信号强度与蛋白浓度(0.1-3.0 mg/m L)呈良好线性关系。将所建方法用于实际样品分析,牛跟腱胶原蛋白含量为90.2%,胶原海绵中胶原蛋白含量为93.4%,检测结果与基于氨基酸组成分析的结果一致。该研究表明基于HPLC-MS的特征多肽分析方法进行胶原蛋白定量检测具有可行性,该方法在含胶原蛋白医疗器械等生物制品质量控制方面具有应用前景。     

液质联用多反应监测法定量目标多肽或蛋白质

为建立优化的血浆内源性多肽提取方法,并且构建目标多肽和蛋白质的质谱定量方 法,本研究考察了超滤法、有机溶剂沉淀法和固相萃取法对血浆内源性多肽的提取效果 ,并通过Tricine-SDS-PAGE对提取效果进行比较.通过液相色谱串联质谱多反应监测 （MRM）分析,建立了多肽标准品ESAT-6定量方法,并将ESAT-6定量建立的液相色谱和质谱条件应用于蛋白质的定量,对多肽和蛋白质MRM定量的标准曲线进行了考 察.Tricine-SDS-PAGE结果表明,乙腈沉淀法是最佳的血浆内源性多肽提取方法,低分子量的多肽可以得到很好的富集,且能有效地去除高分子蛋白质的污染.液相色谱串联 质谱MRM法检测血浆内提取的多肽,标准曲线的线性较好,相关系数为0.999.另外,采 用MRM法对胶内分离的蛋白质进行定量,标准曲线的线性相关系数为0.995.综上所述, 本研究构建了一种简单有效的血浆多肽提取方法,通过液质联用MRM法成功地实现了目标多肽和蛋白质定量测定.该定量方法可以推广应用于复杂样品中的多肽和蛋白质的定 量分析.     

高效液相色谱-串联质谱检测基因组DNA甲基化方法的建立

目的:建立高效液相色谱-串联质谱(HPLC-ESI-MS/MS)检测基因组DNA甲基化水平的方法。方法:以5-mdC和dG为标准品,采用全自动高效液相色谱系统进行分离,串联电喷雾质谱检测,选择多反应监测模式(MRM)测定标准品,绘制标准工作曲线。结果:在MRM模式下选取5-mdC(m/z 241.9→126.3)和dG(m/z 268.1→152.3)分别作为定量检测的母子离子对,各化合物能实现良好的基线分离;5-mdC和dG碰撞能均为15 eV,去簇电压分别为40和45 V,最低定量限分别为1.65和2.47 fmol;标准品的响应值比为90%~110%;5-mdC含量的天内相对标准偏差和天间相对标准偏差均小于8%。结论:HPLC-ESI-MS/MS是能应用于检测基因组DNA甲基化的一种高通量、高准确率、高分辨率、高灵敏度且重复性好的方法。     

建立高效液相色谱-串联质谱检测细胞内腺苷酸浓度的方法及其应用

细胞内腺苷酸浓度变化是细胞能量代谢改变的感应器,建立高效液相色谱-串联质谱法检测细胞内腺苷酸浓度的方法有助于监测药物对细胞能量代谢的影响．用含有Na-EDTA的高氯酸溶液超声裂解细胞．采用超高效HSS T3色谱柱 (2.1 mm ×100 mm, 1.8 μm),以8 mmol/L N, N-二甲基己胺(DMHA)水溶液和乙腈为流动相进行梯度洗脱,采用正离子模式质谱检测,在多反应监测(MRM)模式下进行定性定量分析．结果表明,AMP、ADP和ATP分别在(0.1814～14.5164) μmol/L、(0.2342～18.7354) μmol/L和(0.2003～16.0260) μmol/L线性范围内具有良好的线性关系,其相关系数分别为0.9984、0.9964和0.9990．AMP、ADP和ATP的检出限(LOD,S/N>3)分别为1.9291、1.8794 和166.5 nmol/L,定量限(LOQ,S/N>10)为1.9632、1.9672和185.6 nmol/L,且加标回收率为81.8% ～107.8%,相对标准偏差小于7.55%．AMP、ADP和ATP的日内偏差(RSD)分别为6.16%、5.13%和7.66%,日间偏差(RSD)分别为6.36%、2.74%和6.77%．该方法快速、简单、灵敏,能满足细胞内AMP、ADP和ATP含量的检测要求．通过检测分析在不同浓度高良姜挥发油作用下人肺癌A549细胞内AMP、ADP和ATP含量变化,结果显示细胞总的腺苷酸水平和能荷呈浓度依赖性下降,且当浓度达到500 mg/L时ATP/TAN明显下降,而A549细胞中AMP/ATP比例水平呈浓度依赖性增加．这提示高良姜挥发油可通过影响细胞能量代谢抑制细胞增殖．     

白喉类毒素酶联免疫检测法的建立及初步应用

目的建立测定吸附无细胞百白破联合疫苗中白喉类毒素酶联免疫检测(ELISA)方法,并进行验证及初步应用。方法以高效价兔抗DT多克隆抗体和相应酶标抗体建立双抗体夹心ELISA法,确定线性范围同时验证该方法的重复性和特异性等确定检测限度,并初步应用。结果 DT含量在0~0.0160 Lf/m L范围内反应曲线线性关系良好(r0.99)。该方法与破伤风类毒素(Tetanus toxoid,TT)、百日咳毒素(Pertussis toxin,PT)、百日咳丝状血凝素(Filamantous hemagglutinin,FHA)与黏着素(Pertactin,Prn)无明显交叉反应,重复性好、特异性较强,精密度及准确度验证均符合常规质控要求,通过验证确定的准确检测范围为0.000 8~0.016 0 Lf/m L;检测限度为0.000 8 Lf/m L。该方法对DT抗原进行了吸附率的检测,同时检测了10批白喉类毒素原液与《中华人民共和国药典》三部2010年版规定的絮状单位检测方法进行对比,变异系数低于20%。结论建立了白喉类毒素双抗体夹心ELISA检测方法,为吸附无细胞百白破联合疫苗生产过程中白喉类毒素含量的质量控制提供了有效技术手段。     

HPLC-MS/MS法检测星形胶质细胞兴奋性氨基酸释放

目的:建立一种快速测定星形胶质细胞上清中兴奋性氨基酸释放的高效液相-串联四级杆质谱方法.方法:使用高效液相-串联四极杆质谱的多反应监测(MRM)模式快速测定星形胶质细胞(AST)兴奋性氨基酸(EAAs)的释放量.结果:该方法检测细胞上清液中兴奋性氨基酸释放量能够在4分钟内完成,有很好的精密度(Glu 1.0%,Asp 1.6%),较好的稳定性(组内的变异系数Glu为1.34%,Asp为1.41%;组间变异系数Glu为2.32%,Asp为2.18%)和回收率(Glu 97.1%;Asp 95.8%).结论:该方法定量检测兴奋性氨基酸快速、准确,可用于大批量样品的快速测定.     

植物代谢组学中几种重要的次生代谢物液质分析技术研究进展

代谢组学（metabolomics）主要是研究生物体、组织、细胞的代谢物组分及检测其动态变化过程,是继基因组和蛋白组学后新兴的一门组学技术。代谢物是细胞调节过程中的最终产物,其水平被视为生物系统对遗传或环境变化的最终反映。通过合适的分析平台,准确定性、定量在复杂的生物中具有化学多样性的次生代谢物是代谢组学的一项重要工作。液相色谱-串联质谱技术（liquid chromatography-tandem mass spectrometry,LC-MS/MS）是代谢物质检测平台最常用的方法,也为植物次生代谢物的广泛应用研究提供了基础。本文主要从植物激素类、叶酸类、黄酮类等次生代谢物方面进行阐述,结合液质联用技术,简要论述不同次生代谢物检测技术的研究进展。     

双抗夹心ELISA法在无细胞百日咳疫苗生产质控中的应用

实验中对无细胞百日咳疫苗的脱毒工序优化后,采用双抗夹心ELISA法来检测百日咳有效组分含量,同时采用效价试验方法来验证结果。ELISA法定量测定有效成分的结果和效价试验结果均证明达到《中国药典》三部2005版的要求。由于双抗夹心ELISA法特异性强,灵敏度高,适用于无细胞百日咳疫苗生产各个环节的质量控制。     

A rapid and quantitative LC-MS/MS method to profile sphingolipids

Sphingolipids comprise a highly diverse and complex class of molecules that serve not only as structural components of membranes but also as signaling molecules. To understand the differential role of sphingolipids in a regulatory network, it is important to use specific and quantitative methods. We developed a novel LC-MS/MS method for the rapid, simultaneous quantification of sphingolipid metabolites, including sphingosine, sphinganine, phyto-sphingosine, di- and trimethyl-sphingosine, sphingosylphosphorylcholine, hexosylceramide, lactosylceramide, ceramide-1-phosphate, and dihydroceramide-1-phosphate. Appropriate internal standards (ISs) were added prior to lipid extraction. In contrast to most published methods based on reversed phase chromatography, we used hydrophilic interaction liquid chromatography and achieved good peak shapes, a short analysis time of 4.5 min, and, most importantly, coelution of analytes and their respective ISs. To avoid an overestimation of species concentrations, peak areas were corrected regarding isotopic overlap where necessary. Quantification was achieved by standard addition of naturally occurring sphingolipid species to the sample matrix. The method showed excellent precision, accuracy, detection limits, and robustness. As an example, sphingolipid species were quantified in fibroblasts treated with myriocin or sphingosine-kinase inhibitor. In summary, this method represents a valuable tool to evaluate the role of sphingolipids in the regulation of cell functions.     

霍乱疫苗中残余霍乱毒素检测方法的建立及验证

采用间接酶联免疫法,即用神经节苷脂包被,加入待检样品,再加入兔抗霍乱毒素B亚单位抗体,用标准样品的吸光值(A值)对标准样品的浓度绘制4-参数拟合曲线,根据标准曲线计算出待测样品中的CT浓度。结果显示,在浓度范围(0.6～16)ng/ml之间,CT标准浓度和检测浓度成线性关系,r2=0.9986。精确度在浓度范围(0.6～16)ng/ml,CT的平均回收率在96.24%～114.44%之间。精密度:批内变异CV%≤12.98%,批间变异CV%≤18.48%。特异性CT浓度在10ng/ml时,平均回收率为102.6%;CT浓度在5ng/ml时,平均回收率为111.17%;CT浓度在2.5ng/ml时,平均回收率为123.83%。实验表明该方法可检测霍乱疫苗原液中CT的含量。     

A quantitative LC-MS/MS method for comparative analysis of capture-antibody affinity toward protein antigens

A mass spectrometry-based antibody selection procedure was developed to evaluate optimal 'capture' monoclonal antibodies that can be used in a variety of analytical measurement applications. The isotope-dilution liquid chromatography-tandem mass spectrometry (ID LC-MS/MS) methodology is based on the use of multiple-reaction monitoring of tryptic peptide fragments derived from protein antigens. A panel of monoclonal antibodies (mAb) was evaluated based on a quantitative determination of relative binding affinity to human cardiac troponin I following immunoprecipitation. Dissociation constants (K(d)) were determined for 'bound mAb-antigen' vs. 'unbound antigen' using non-linear regression analysis. Relative quantification of both antigen and antibody was based on the use of stable isotope-labeled synthetic peptides as internal standards. Optimal 'capture' mAbs were determined through evaluation of relative K(d) constants of all monitored peptide transitions. A panel of six pre-screened candidate capture mAbs was concluded to consist of two subsets of mAbs, each with statistically equivalent K(d) constants as determined using NIST Standard Reference Material (SRM) 2921 - Human Cardiac Troponin Complex. This ID LC-MS/MS method is shown to be capable of quantitatively differentiating mAbs based on relative binding affinities. Selection of optimal capture mAbs can be applied toward a number of analytical applications which require metrological traceability and unbiased quantification.     

重组人睫状神经营养因子蛋白质定量检测方法的建立

采用ELISA双抗体夹心法,建立一种快速灵敏的定量检测rhCNTF成品蛋白含量的方法。结果显示,rhC-NTF抗原浓度在(0～25)ng范围内线性良好(r>0.99),灵敏度为0.3ng/ml,与其他重组细胞因子无交叉反应,样品的检测结果与理论含量相吻合,CV<15%,该方法检测速度快、重复性好、灵敏度高、特异性好。     

An LC-MS/MS method for determination of forsythiaside in rat plasma and application to a pharmacokinetic study

A highly sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of forsythiaside in rat plasma using epicatechin as internal standard. The analytes were extracted by solid-phase extraction and chromatographied on a C₁₈ column eluted with a gradient mobile phase of acetonitrile and water both containing 0.2% formic acid. The detection was performed by negative ion electrospray ionization in multiple reaction monitoring mode, monitoring the transitions m/z 623 → 161 and m/z 289 → 109 for forsythiaside and epicatechin, respectively. The assay was linear over the concentration ranges of 2.0–50.0 and 50.0–5000.0 ng/mL with limits of detection and quantification of 0.2 and 1.0 ng/mL, respectively. The precision was <10.8% and the accuracy was >91.9%, and extraction recovery ranged from 81.3% to 85.0%. This method was successfully applied to a pharmacokinetic study of forsythiaside in rats after intravenous (20 mg/kg) and oral (100 mg/kg) administration, and the result showed that the compound was poorly absorbed with an absolute bioavailability being approximately 0.5%.     

Enantioselective LC-MS/MS method for the determination of cloperastine enantiomers in rat plasma and its pharmacokinetic application

Cloperastine is a central antitussive used to reduce the frequency and intensity of coughing on a short-term basis. In this study, a reliable chiral LC-MS/MS technology has been developed for the quantification of cloperastine enantiomers in the rat plasma. Carbinoxamine was selected as the internal standard. The enantioseparation of cloperastine was performed on a Chiralpak IA column with a mobile phase composed of acetonitrile-water-ammonium hydroxide (80:20:0.1, v/v/v) at a flow rate of 0.6 mL/min. Cloperastine enantiomers were detected by mass spectrometry in multiple reaction monitoring mode with a positive electrospray ionization source. The method was validated over the linear concentration range of 0.05 to 10.0 ng/mL (5.0 × 10⁻⁴ ng to 0.10 ng) for both enantiomers. The lower limit of quantification (LLOQ) for each analyte was determined as 0.05 ng/mL. The relative standard deviations (RSDs) of intraday and interday precision was less than 13.9%, and the relative error (RE) of accuracy ranged from −5.4% to 6.1%, which were within the acceptance criteria. Finally, an application to the stereoselective pharmacokinetics of cloperastine in rats was successfully realized in our assay. The developed method on a commercially available Chiralpak IA column under isocratic mobile phase is advantageous to analyze cloperastine enantiomers in plasma samples collected for enantioselective metabolism or drug interaction studies.     

Development of an LC-MS/MS method for the quantitation of 55 compounds prescribed in combined cardiovascular therapy

This paper reports an LC–MS/MS method with positive electrospray ionization for the screening of commonly prescribed cardiovascular drugs in human plasma, including compounds with antihypertensive (57), antidiabetic (12), hypolipemiant (5), anticoagulant (2) and platelet anti-aggregation (2) effects. Sample treatment consisted of a simple protein precipitation with MeOH/0.1 M ZnSO₄ (4:1, v/v) solution after the addition of internal standard, followed by evaporation and reconstitution. Analytes separation was performed on a Polar-RP column (150 mm × 2 mm, 4 μm) using a gradient elution of 15 min. The MS system was operated in MRM mode, monitoring one quantitation and one confirmation transition for each analyte. The recovery of the protein precipitation step ranged from 50 to 70% for most of the compounds, while some were considerably affected by matrix effects. Since several analytes fulfilled the linearity, accuracy and precision values required by the ICH guidelines, the method proved to be suitable for their quantitative analysis. The limits of quantitation varied from 0.38 to 9.1 μg/L and the limits of detection from 0.12 to 5.34 μg/L. The method showed to be suitable for the detection of plasma samples of patients under cardiovascular treatment with the studied drugs, and for 55 compounds reliable quantitative results could be obtained.     

Quantification of potassium levels in cells treated with Bordetella adenylate cyclase toxin

The aim of this study was to compare two methods for quantification of changes in intracellular potassium concentration (decrease from ∼140 to ∼20 mM) due to the action of a pore-forming toxin, the adenylate cyclase toxin (CyaA) from the pathogenic bacterium Bordetella pertussis. CyaA was incubated with stably transfected K1 Chinese hamster ovary cells expressing the toxin receptor CD11b/CD18 and the decrease in potassium concentration in the cells was followed by inductively coupled plasma mass spectrometry (ICP–MS). It is shown that this method is superior in terms of sensitivity, accuracy, and temporal resolution over the method employing the potassium-binding benzofuran isophthalate–acetoxymethyl ester fluorescent indicator. The ICP–MS procedure was found to be a reliable and straightforward analytical approach enabling kinetic studies of CyaA action at physiologically relevant toxin concentrations (<1000 ng/ml) in biological microsamples.