Characterization and studies of proteome are challenging because biological samples are complex, with a wide dynamic range of abundance. At present the proteins are identified by digestion into peptides, with subsequent identification of the peptides by mass spectrometry (MS). MS is a powerful technique for the purpose, but it cannot identify every peptide in such complex mixtures simultaneously. For accurate analysis and quantification it is important to separate the peptides first by chro- matography into fractions of a size that MS can handle. With these less complex fractions, the probability is increased of identi- fying peptides of low abundance that would otherwise experience ion suppression effects due to the presence of peptides of high abundance. Enrichment for peptides with certain post-translational modifications helps to increase their detection rates as well. Electrostatic repulsion-hydrophilic interaction chromatography (ERLIC) is a mixed-mode chromatographic technique which combines the use of electrostatic repulsion and hydrophilic interaction. This review provides an overview of ERLIC and its var- ious proteomics applications. ERLIC has been demonstrated to have good orthogonality to reverse phase liquid chromatography (RPLC), making it useful as a first dimension in multidimensional liquid chromatography (MDLC) and fractionation of digests in general. Peptides elute in order of their isoelectric points and polarity. ERLIC has also been successfully utilized for the enrichment for phosphopeptides and glycopeptides, facilitating their identification. In addition, it is promising for the study of peptide deamidation. ERLIC performs comparably well or better than established methods for these various applications, and serves as a viable and efficient workflow alternative.
{"title":"The Use of Electrostatic Repulsion-Hydrophilic Interaction Chromatography (ERLIC) for Proteomics Research","authors":"J. T. Ng, P. Hao, S. Sze","doi":"10.5478/MSL.2014.5.4.95","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.4.95","url":null,"abstract":"Characterization and studies of proteome are challenging because biological samples are complex, with a wide dynamic range of abundance. At present the proteins are identified by digestion into peptides, with subsequent identification of the peptides by mass spectrometry (MS). MS is a powerful technique for the purpose, but it cannot identify every peptide in such complex mixtures simultaneously. For accurate analysis and quantification it is important to separate the peptides first by chro- matography into fractions of a size that MS can handle. With these less complex fractions, the probability is increased of identi- fying peptides of low abundance that would otherwise experience ion suppression effects due to the presence of peptides of high abundance. Enrichment for peptides with certain post-translational modifications helps to increase their detection rates as well. Electrostatic repulsion-hydrophilic interaction chromatography (ERLIC) is a mixed-mode chromatographic technique which combines the use of electrostatic repulsion and hydrophilic interaction. This review provides an overview of ERLIC and its var- ious proteomics applications. ERLIC has been demonstrated to have good orthogonality to reverse phase liquid chromatography (RPLC), making it useful as a first dimension in multidimensional liquid chromatography (MDLC) and fractionation of digests in general. Peptides elute in order of their isoelectric points and polarity. ERLIC has also been successfully utilized for the enrichment for phosphopeptides and glycopeptides, facilitating their identification. In addition, it is promising for the study of peptide deamidation. ERLIC performs comparably well or better than established methods for these various applications, and serves as a viable and efficient workflow alternative.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72786648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lincomycin is one of the major species among the Pharmaceuticals and Personal Care Products (PPCPs) detected from the four major rivers in Korea. The structure characterization was performed of six degradation products of lincomycin formed under the irradiation of electron beam, and the degradation efficiency as a function of the various irradiation dose and sample concentration was investigated. Electron beam (10 MeV, 0.5 mA and 5 kW) experiments for the structural characteriza- tion of degradation products that are fortified with lincomycin, were performed at the dose of 10 kGy. The separation of degrada- tion products and lincomycin was carried out using a C18 column (2.1×100 mm, 3.5 µm), using gradient elution with 20 mM ammonium acetate and acetonitrile. The structures of six degradation products of lincomycin were proposed by interpretation of mass spectra and chromatograms by LC-MS/MS. The mass fragmentation pathways of mass spectra in tandem mass spectrome- try were also proposed. Experiments were performed of the degradation efficiency as a function of the irradiation dose intensity and the initial concentration of lincomycin in an aqueous environment. In addition, increased degradation efficiency was observed with a higher dose of electron beam and lower concentration.
林可霉素是在国内4大河流中检测出的药品和个人护理用品(ppcp)中的主要种类之一。对电子束辐照下形成的6种林可霉素降解产物进行了结构表征，并考察了不同辐照剂量和样品浓度对降解效率的影响。用10 kGy剂量的电子束(10 MeV, 0.5 mA, 5 kW)研究了林可霉素强化降解产物的结构特征。采用C18色谱柱(2.1×100 mm, 3.5µm)分离降解产物和林可霉素，用20 mm乙酸铵和乙腈梯度洗脱。通过质谱分析和质谱分析，确定了6种降解产物的结构。提出了串联质谱法质谱的质谱碎片化途径。实验研究了林可霉素在水环境中的初始浓度和辐照剂量对降解效率的影响。此外，随着电子束剂量的增加和浓度的降低，降解效率提高。
{"title":"Degradation Efficiency and Characterization of Lincomycin by Electron Beam Irradiation","authors":"Hyun-Sun Ham, Hyun-Woo Cho, S. Myung","doi":"10.5478/MSL.2014.5.3.89","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.3.89","url":null,"abstract":"Lincomycin is one of the major species among the Pharmaceuticals and Personal Care Products (PPCPs) detected from the four major rivers in Korea. The structure characterization was performed of six degradation products of lincomycin formed under the irradiation of electron beam, and the degradation efficiency as a function of the various irradiation dose and sample concentration was investigated. Electron beam (10 MeV, 0.5 mA and 5 kW) experiments for the structural characteriza- tion of degradation products that are fortified with lincomycin, were performed at the dose of 10 kGy. The separation of degrada- tion products and lincomycin was carried out using a C18 column (2.1×100 mm, 3.5 µm), using gradient elution with 20 mM ammonium acetate and acetonitrile. The structures of six degradation products of lincomycin were proposed by interpretation of mass spectra and chromatograms by LC-MS/MS. The mass fragmentation pathways of mass spectra in tandem mass spectrome- try were also proposed. Experiments were performed of the degradation efficiency as a function of the irradiation dose intensity and the initial concentration of lincomycin in an aqueous environment. In addition, increased degradation efficiency was observed with a higher dose of electron beam and lower concentration.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81170089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kang, H. R. Cho, Dong Hoon Lee, D. Yeom, Y. Choi, Y. S. Choi
Three different dutasteride extraction methods were compared and a method based on liquid-liquid extraction (LLE) using methyl tert-butyl ether and methylene chloride was proved to be more effective than others for the extraction of dutasteride and finasteride, the internal standard (IS), from rat plasma. Additionally, a method composed of the LLE extraction, liquid chro- matography, and multiple reaction monitoring (MRM) to target dutasteride and IS was validated by assessing specificity, linear- ity (r 2 = 0.9993, 5 - 400 ng/mL), sensitivity (the limit of detection: 4.03 ng/mL; the limit of quantitation: 12.10 ng/mL), accuracy (intra-day: 89.4 - 105.9%; inter-day: 84.9 - 100.9%), precision (intra-day: 0.8 - 6.9%; inter-day: 2.9 - 15.9%), and recovery (84.7 - 107.8%). Since the validated method was successfully applied to a pharmacokinetic study of dutasteride, it can be useful for the pharmacokinetic evaluation of newly developed dutasteride formulations.
{"title":"A Method to Monitor Dutasteride in Rat Plasma Using Liquid-Liquid Extraction and Multiple Reaction Monitoring: Comparisons and Validation","authors":"M. Kang, H. R. Cho, Dong Hoon Lee, D. Yeom, Y. Choi, Y. S. Choi","doi":"10.5478/MSL.2014.5.3.79","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.3.79","url":null,"abstract":"Three different dutasteride extraction methods were compared and a method based on liquid-liquid extraction (LLE) using methyl tert-butyl ether and methylene chloride was proved to be more effective than others for the extraction of dutasteride and finasteride, the internal standard (IS), from rat plasma. Additionally, a method composed of the LLE extraction, liquid chro- matography, and multiple reaction monitoring (MRM) to target dutasteride and IS was validated by assessing specificity, linear- ity (r 2 = 0.9993, 5 - 400 ng/mL), sensitivity (the limit of detection: 4.03 ng/mL; the limit of quantitation: 12.10 ng/mL), accuracy (intra-day: 89.4 - 105.9%; inter-day: 84.9 - 100.9%), precision (intra-day: 0.8 - 6.9%; inter-day: 2.9 - 15.9%), and recovery (84.7 - 107.8%). Since the validated method was successfully applied to a pharmacokinetic study of dutasteride, it can be useful for the pharmacokinetic evaluation of newly developed dutasteride formulations.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88221789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sun Ju Kim, O. Heungchan, Jeong Ah Kim, Seung Ho Lee, Sangkyu Lee
Licoricidin isolated from Glycyrrhiza uralensis is known to have anticancer, anti-nephritic, anti-Helicobacter pylori, and antibacterial effects. In this study, a cocktail probe assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to investigate the modulating effect of licoricidin on cytochrome P450 (CYP) enzymes in human liver microsomes. When licoricidin was incubated at with CYP probes for 60 min at , it showed potent inhibitory effects on CYP2B6-catalyzed bupropion hydroxylation and CYP2C9-catalyzed diclofenac 4`-hydroxylation with half maximal inhibitory concentration () values of 3.4 and , respectively. The inhibition mode of licoricidin was revealed as competitive, dose-dependent, and non-time-dependent, and following the pattern of Lineweaver-Burk plots. The inhibitory effect of licoricidin has been confirmed in human recombinant cDNA-expressed CYP2B6 and 2C9 with values of 4.5 and , respectively. In conclusion, this study has shown the potent inhibitory effect of licoricidin on CYP2B6 and CYP2C9 activity could be important for predicting potential herb-drug interactions with substrates that mainly undergo CYP2B- and CYP2C9-mediated metabolism.
{"title":"In Vitro Inhibitory Effect of Licoricidin on Human Cytochrome P450s","authors":"Sun Ju Kim, O. Heungchan, Jeong Ah Kim, Seung Ho Lee, Sangkyu Lee","doi":"10.5478/MSL.2014.5.3.84","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.3.84","url":null,"abstract":"Licoricidin isolated from Glycyrrhiza uralensis is known to have anticancer, anti-nephritic, anti-Helicobacter pylori, and antibacterial effects. In this study, a cocktail probe assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to investigate the modulating effect of licoricidin on cytochrome P450 (CYP) enzymes in human liver microsomes. When licoricidin was incubated at with CYP probes for 60 min at , it showed potent inhibitory effects on CYP2B6-catalyzed bupropion hydroxylation and CYP2C9-catalyzed diclofenac 4`-hydroxylation with half maximal inhibitory concentration () values of 3.4 and , respectively. The inhibition mode of licoricidin was revealed as competitive, dose-dependent, and non-time-dependent, and following the pattern of Lineweaver-Burk plots. The inhibitory effect of licoricidin has been confirmed in human recombinant cDNA-expressed CYP2B6 and 2C9 with values of 4.5 and , respectively. In conclusion, this study has shown the potent inhibitory effect of licoricidin on CYP2B6 and CYP2C9 activity could be important for predicting potential herb-drug interactions with substrates that mainly undergo CYP2B- and CYP2C9-mediated metabolism.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87562940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Microglia are the confined immune cells of the central nervous system (CNS). In response to injury or infection,microglia readily become activated and release proinflammatory mediators that are believed to contribute to microglia-mediatedneurodegeneration. In the present study, inflammation was induced in the immortalized murine microglial cell line BV-2 bylipopolysaccharide (LPS) treatment. We firstly performed phosphoproteomics analysis and phosphoinositide lipidomics analysiswith LPS activated microglia in order to compare phosphorylation patterns in active and inactive microglia and to detect the pa t-tern of changes in phosphoinositide regulation upon activation of microglia. Mass spectrometry analysis of the phosphopro-teome of the LPS treatment group compared to that of the untreated control group revealed a notable increase in the diversity ofcellular phosphorylation upon LPS treatment. Additionally, a lipidomics analysis detected significant increases in the amounts ofphosphoinositide species in the LPS treatment. This investigation could provide an insight for understanding molecular mecha-nisms underlying microglia-mediated neurodegenerative diseases.Key words: Microglia, Lipopolysaccharide (LPS), Neuroinflammation, Phosphoproteomics, Lipidomics, Phosphoinositide
{"title":"Investigation on Lipopolysaccharide Activated Microglia by Phosphoproteomics and Phosphoinositide Lipidomics","authors":"Young Jun Kim, Hackyoung Kim, Kwangmo Noh","doi":"10.5478/MSL.2014.5.3.70","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.3.70","url":null,"abstract":"Abstract: Microglia are the confined immune cells of the central nervous system (CNS). In response to injury or infection,microglia readily become activated and release proinflammatory mediators that are believed to contribute to microglia-mediatedneurodegeneration. In the present study, inflammation was induced in the immortalized murine microglial cell line BV-2 bylipopolysaccharide (LPS) treatment. We firstly performed phosphoproteomics analysis and phosphoinositide lipidomics analysiswith LPS activated microglia in order to compare phosphorylation patterns in active and inactive microglia and to detect the pa t-tern of changes in phosphoinositide regulation upon activation of microglia. Mass spectrometry analysis of the phosphopro-teome of the LPS treatment group compared to that of the untreated control group revealed a notable increase in the diversity ofcellular phosphorylation upon LPS treatment. Additionally, a lipidomics analysis detected significant increases in the amounts ofphosphoinositide species in the LPS treatment. This investigation could provide an insight for understanding molecular mecha-nisms underlying microglia-mediated neurodegenerative diseases.Key words: Microglia, Lipopolysaccharide (LPS), Neuroinflammation, Phosphoproteomics, Lipidomics, Phosphoinositide","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82171246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Donggeun Oh, Sunyoung Lee, Meehyang Kwon, Sook‐Kyung Kim, M. Moon, Dukjin Kang
In this study, we present a new isotope-coded carbamidomethylation (iCCM)-based quantitative proteomics, as a complementary strategy for conventional isotope labeling strategies, with providing the simplicity, ease of use, and robustness. In iCCM-based quantification, two proteome samples can be separately isotope-labeled by means of covalently reaction of all cysteinyl residues in proteins with iodoacetamide (IAA) and its isotope (IAA- 13 C2, D2), denoted as CM and iCCM, respectively, leading to a mass shift of all cysteinyl residues to be + 4 Da. To evaluate iCCM-based isotope labeling in proteomic quantifica- tion, 6 protein standards (i.e., bovine serum albumin, serotransferrin, lysozyme, beta-lactoglobulin, beta-galactosidase, and alpha-lactalbumin) isotopically labeled with IAA and its isotope, mixed equally, and followed by proteolytic digestion. The resulting CM-/iCCM-labeled peptide mixtures were analyzed using a nLC-ESI-FT orbitrap-MS/MS. From our experimental results, we found that the efficiency of iCCM-based quantification is more superior to that of mTRAQ, as a conventional noniso- baric labeling method, in which both of a number of identified peptides from 6 protein standards and the less quantitative varia- tions in the relative abundance ratios of heavy-/light-labeled corresponding peptide pairs. Finally, we applied the developed iCCM-based quantitative method to lung cancer serum proteome in order to evaluate the potential in biomarker discovery study
{"title":"A Simple Carbamidomethylation-Based Isotope Labeling Method for Quantitative Shotgun Proteomics","authors":"Donggeun Oh, Sunyoung Lee, Meehyang Kwon, Sook‐Kyung Kim, M. Moon, Dukjin Kang","doi":"10.5478/MSL.2014.5.3.63","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.3.63","url":null,"abstract":"In this study, we present a new isotope-coded carbamidomethylation (iCCM)-based quantitative proteomics, as a complementary strategy for conventional isotope labeling strategies, with providing the simplicity, ease of use, and robustness. In iCCM-based quantification, two proteome samples can be separately isotope-labeled by means of covalently reaction of all cysteinyl residues in proteins with iodoacetamide (IAA) and its isotope (IAA- 13 C2, D2), denoted as CM and iCCM, respectively, leading to a mass shift of all cysteinyl residues to be + 4 Da. To evaluate iCCM-based isotope labeling in proteomic quantifica- tion, 6 protein standards (i.e., bovine serum albumin, serotransferrin, lysozyme, beta-lactoglobulin, beta-galactosidase, and alpha-lactalbumin) isotopically labeled with IAA and its isotope, mixed equally, and followed by proteolytic digestion. The resulting CM-/iCCM-labeled peptide mixtures were analyzed using a nLC-ESI-FT orbitrap-MS/MS. From our experimental results, we found that the efficiency of iCCM-based quantification is more superior to that of mTRAQ, as a conventional noniso- baric labeling method, in which both of a number of identified peptides from 6 protein standards and the less quantitative varia- tions in the relative abundance ratios of heavy-/light-labeled corresponding peptide pairs. Finally, we applied the developed iCCM-based quantitative method to lung cancer serum proteome in order to evaluate the potential in biomarker discovery study","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86833010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yeoun Hur, Sookil Tae, Yun-Joo Koh, S. Hong, Y. H. Yoon, H. Jang, Sooji Kim, K. Kim, S. Kang, Young-Shin Lee, S. Han
A specific and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method (LC-ESI- MS/MS) was developed and validated for the simultaneous quantification of porphyrins (coproporphyrin, pentacarboxylporphy- rin, hexacarboxylporphyrin, heptacarboxylporphyrin, and uroporphyrin) in human plasma and urine. Acidified plasma samples and urine samples were prepared by using liquid-liquid extraction using ethyl acetate and protein precipitation with acetonitrile, respectively. The separation was achieved onto a Synergi Fusion RP column (150 mm × 2.0 mm, 4 µm) with a gradient elution of mobile phase A (0.1% formic acid in 2 mmol/L ammonium acetate, v/v) and mobile phase B (20% methanol in acetonitrile, v/ v) at a flow rate of 450 µL/min. Porphyrins and the internal standard (IS), coproporphyrin I- 15 N4, were detected by a tandem mass spectrometer equipped with an electrospray ion source operating in positive ion mode. Multiple reaction monitoring (MRM) transitions of the protonated precursor ions and the related product ions were optimized to increase selectivity and sensi- tivity. The proposed method was validated by assessing selectivity, linearity, limit of quantification (LOQ), precision, accuracy, recovery, and stability. The calibration curves were obtained in the range of 0.1-100 nmol/L and the LOQs were estimated as 0.1 nmol/L for all porphyrins. Results obtained from the validation study of porphyrins showed good accuracy, precision, recov- ery, and stability. Finally, the proposed method was successfully applied to clinical studies on the autism spectrum disorder (ASD) diagnosis of 203 Korean children.
建立了一种高效、灵敏的液相色谱-电喷雾串联质谱(LC-ESI- MS/MS)同时定量测定人血浆和尿液中卟啉(共比例卟啉、五羧基卟啉、六羧基卟啉、七羧基卟啉和uroporphyin)的方法。酸化血浆样品和尿液样品分别采用乙酸乙酯液液萃取和乙腈蛋白沉淀制备。在Synergi Fusion RP柱(150 mm × 2.0 mm, 4µm)上进行分离，流动相a(0.1%甲酸/ 2 mmol/L乙酸铵，v/v)和流动相B(20%甲醇/乙腈，v/v)以450µL/min的流速梯度洗脱。采用电喷雾离子源为正离子模式的串联质谱仪对卟啉和内标物coproporphyrin I- 15n4进行了检测。优化了质子化前体离子和相关产物离子的多反应监测(MRM)跃迁，以提高选择性和灵敏度。通过选择性、线性、定量限(LOQ)、精密度、准确度、回收率和稳定性等指标对该方法进行了验证。标定曲线在0.1 ~ 100 nmol/L范围内，所有卟啉的定量限均为0.1 nmol/L。结果表明，该方法具有良好的准确度、精密度、回收率和稳定性。最后，将该方法成功应用于203例韩国儿童自闭症谱系障碍(ASD)诊断的临床研究。
{"title":"Simultaneous Determination of Five Porphyrins in Human Urine and Plasma Using High Performance Liquid Chromatography-Tandem Mass Spectrometry","authors":"Yeoun Hur, Sookil Tae, Yun-Joo Koh, S. Hong, Y. H. Yoon, H. Jang, Sooji Kim, K. Kim, S. Kang, Young-Shin Lee, S. Han","doi":"10.5478/MSL.2014.5.2.42","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.2.42","url":null,"abstract":"A specific and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method (LC-ESI- MS/MS) was developed and validated for the simultaneous quantification of porphyrins (coproporphyrin, pentacarboxylporphy- rin, hexacarboxylporphyrin, heptacarboxylporphyrin, and uroporphyrin) in human plasma and urine. Acidified plasma samples and urine samples were prepared by using liquid-liquid extraction using ethyl acetate and protein precipitation with acetonitrile, respectively. The separation was achieved onto a Synergi Fusion RP column (150 mm × 2.0 mm, 4 µm) with a gradient elution of mobile phase A (0.1% formic acid in 2 mmol/L ammonium acetate, v/v) and mobile phase B (20% methanol in acetonitrile, v/ v) at a flow rate of 450 µL/min. Porphyrins and the internal standard (IS), coproporphyrin I- 15 N4, were detected by a tandem mass spectrometer equipped with an electrospray ion source operating in positive ion mode. Multiple reaction monitoring (MRM) transitions of the protonated precursor ions and the related product ions were optimized to increase selectivity and sensi- tivity. The proposed method was validated by assessing selectivity, linearity, limit of quantification (LOQ), precision, accuracy, recovery, and stability. The calibration curves were obtained in the range of 0.1-100 nmol/L and the LOQs were estimated as 0.1 nmol/L for all porphyrins. Results obtained from the validation study of porphyrins showed good accuracy, precision, recov- ery, and stability. Finally, the proposed method was successfully applied to clinical studies on the autism spectrum disorder (ASD) diagnosis of 203 Korean children.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88110955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gas chromatography-mass spectrometry (GC-MS) methods have been used extensively in clinical steroid analyses. Evaluating the metabolic ratios of precursors to products by accurate quantification of individual steroid levels in biological samples can reveal the activities of enzymes associated with steroid metabolism. This review article discusses the impact of GC- MS-based steroid profiling on our understanding of the biochemical role of steroids and their metabolic enzymes in hormone- dependent diseases, such as congenital adrenal hyperplasia (CAH), cortisol-mediated hypertension, apparent mineralocorticoid excess (AME), male-pattern baldness, and breast and thyroid cancers. Steroid profiling is a comprehensive analytical technique that can be applied whenever the highest specificity is required and may be a reasonable initial diagnostic approach.
{"title":"Diagnostic Evaluation of Enzyme Activity Related to Steroid Metabolism by Mass Spectrometry-Based Steroid Profiling","authors":"Man-Ho Choi, B. Chung","doi":"10.5478/MSL.2014.5.2.35","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.2.35","url":null,"abstract":"Gas chromatography-mass spectrometry (GC-MS) methods have been used extensively in clinical steroid analyses. Evaluating the metabolic ratios of precursors to products by accurate quantification of individual steroid levels in biological samples can reveal the activities of enzymes associated with steroid metabolism. This review article discusses the impact of GC- MS-based steroid profiling on our understanding of the biochemical role of steroids and their metabolic enzymes in hormone- dependent diseases, such as congenital adrenal hyperplasia (CAH), cortisol-mediated hypertension, apparent mineralocorticoid excess (AME), male-pattern baldness, and breast and thyroid cancers. Steroid profiling is a comprehensive analytical technique that can be applied whenever the highest specificity is required and may be a reasonable initial diagnostic approach.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76008470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glycated hemoglobin (HbA1c) is used as an index of mean glycemia over prolonged periods. This study describes an optimization of enzyme digestion conditions for quantification of non-glycated hemoglobin (HbA0) and HbA1c as diagnostic markers of diabetes mellitus. Both HbA0 and HbA1c were quantitatively determined followed by enzyme digestion using iso- tope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with synthesized N-terminal hexapeptides as standards and synthesized isotope labeled hexapeptides as internal standards. Prior to quantification, each peptide was addition- ally quantified by amino acid composition analysis using ID-LC-MS/MS via acid hydrolysis. Each parameter was considered strictly as a means to improve digestion efficiency and repeatability. Digestion of hemoglobin was optimized when using 100 mM ammonium acetate (pH 4.2) and a Glu-C-to-HbA1c ratio of 1:50 at 37 o C for 20 h. Quantification was satisfactorily reproducible with a 2.6% relative standard deviation. These conditions were recommended for a primary reference method of HbA1c quantification and for the certification of HbA1c reference material.
{"title":"Optimization of Enzyme Digestion Conditions for Quantification of Glycated Hemoglobin Using Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry","authors":"Ji-Seon Jeong","doi":"10.5478/MSL.2014.5.2.52","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.2.52","url":null,"abstract":"Glycated hemoglobin (HbA1c) is used as an index of mean glycemia over prolonged periods. This study describes an optimization of enzyme digestion conditions for quantification of non-glycated hemoglobin (HbA0) and HbA1c as diagnostic markers of diabetes mellitus. Both HbA0 and HbA1c were quantitatively determined followed by enzyme digestion using iso- tope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with synthesized N-terminal hexapeptides as standards and synthesized isotope labeled hexapeptides as internal standards. Prior to quantification, each peptide was addition- ally quantified by amino acid composition analysis using ID-LC-MS/MS via acid hydrolysis. Each parameter was considered strictly as a means to improve digestion efficiency and repeatability. Digestion of hemoglobin was optimized when using 100 mM ammonium acetate (pH 4.2) and a Glu-C-to-HbA1c ratio of 1:50 at 37 o C for 20 h. Quantification was satisfactorily reproducible with a 2.6% relative standard deviation. These conditions were recommended for a primary reference method of HbA1c quantification and for the certification of HbA1c reference material.","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84040908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: The effectiveness of tertiary matrices composed of the combination of three common matrices (dihydrobenzoic acid(DHB), α -cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA)) was compared with that of single or binary matri-ces in the analysis of polyethylene glycol (PEG) polymers ranging from 1400 to 10000 Da using matrix-assisted laser desorp-tion/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A tertiary matrix of 2,5-DHB+CHCA+SA was the mosteffective in terms of S/N ratios. CHCA and CHCA+SA produced the highest S/N ratios among the single matrices and thebinary matrices, respectively. The improvement observed when using a tertiary matrix in analyses of PEG polymers by MALDI-TOF MS is believed to be due to the uniform morphology of the MALDI sample spots and synergistic effects arising from themixture of the three matrix materials.Keywords: MALDI-TOF MS, tertiary matrix, polyethylene glycols, 2,5-dihydrobenzoic acid, α -cyano-4-hydroxycinnamicacid, sinapinic acid
{"title":"Tertiary Matrices for the Analysis of Polyethylene Glycols Using MALDI-TOF MS","authors":"Jangmi Hong, Taehee Kim, Jeongkwon Kim","doi":"10.5478/MSL.2014.5.2.49","DOIUrl":"https://doi.org/10.5478/MSL.2014.5.2.49","url":null,"abstract":"Abstract: The effectiveness of tertiary matrices composed of the combination of three common matrices (dihydrobenzoic acid(DHB), α -cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA)) was compared with that of single or binary matri-ces in the analysis of polyethylene glycol (PEG) polymers ranging from 1400 to 10000 Da using matrix-assisted laser desorp-tion/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A tertiary matrix of 2,5-DHB+CHCA+SA was the mosteffective in terms of S/N ratios. CHCA and CHCA+SA produced the highest S/N ratios among the single matrices and thebinary matrices, respectively. The improvement observed when using a tertiary matrix in analyses of PEG polymers by MALDI-TOF MS is believed to be due to the uniform morphology of the MALDI sample spots and synergistic effects arising from themixture of the three matrix materials.Keywords: MALDI-TOF MS, tertiary matrix, polyethylene glycols, 2,5-dihydrobenzoic acid, α -cyano-4-hydroxycinnamicacid, sinapinic acid","PeriodicalId":18238,"journal":{"name":"Mass Spectrometry Letters","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2014-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86288995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：