Introduction Single nucleotide polymorphisms (SNPs) are the most abundant DNA markers in the human genome occurring at a frequency of one in every 500--1000 nucleotides. A variety of methods have been used for the ...Introduction Single nucleotide polymorphisms (SNPs) are the most abundant DNA markers in the human genome occurring at a frequency of one in every 500--1000 nucleotides. A variety of methods have been used for the analysis of single nucleotide polymorphisms, including restriction fragment length polymorphism (RFLP), direct sequencing by using laser-induced fluorescence detectionTM, fluorescence energy transfer, MALDI-TOF MS combined with primer extension or invasive cleavage, and fluorescence polarization. During the past two decades, mass spectrometry has become a very popular tool in the analysis of biomolecules and is perfectly suited to the analysis of single nucleotide polymorphisms (SNPs) due to its speed, low cost, and accuracy. In this work, we used MALDI TOF mass spectrometry to detect the fragments of restriction endonuclease hydrolysis of PCR products flanking a SNP located at paraoxonase 1(Q192R). Compared with electrophoresis, this method requires less time of analysis and possess a higher accuracy.展开更多
Matrix-assisted Laser Desorption/Ionization with Time-of-flight Mass Spectrometry (MALDI-TOFMS) was investigated as a method for the rapid identifica-tion of species. Current demand in microbial identi-fication is how...Matrix-assisted Laser Desorption/Ionization with Time-of-flight Mass Spectrometry (MALDI-TOFMS) was investigated as a method for the rapid identifica-tion of species. Current demand in microbial identi-fication is how to compare unknown strains to the known one quickly, semi-automatically and accurately. In this paper, we present a software tool that allows flexibly microbial matching in a user-friendly way, by letting the users to customize comparison parameters including: in vitro transcription enzyme, mass tolerance,minimum fragment length, intensity threshold and corresponding weights. We provide three spectral scoring functions to compute the affin-ity between the species. Therefore, the precision of microbial comparison increases. To test and verify this tool, we employed experimental spectral data based on MALDI-TOFMS and the gene sequences of E.coli and Salmonella. This software is written in Java for cross-platform intention.展开更多
Gene expression profile changes in brain regions following traumatic brain injury at the gene level cannot sufficiently elucidate gene expression time, expression amount, protein post-translational processing or modif...Gene expression profile changes in brain regions following traumatic brain injury at the gene level cannot sufficiently elucidate gene expression time, expression amount, protein post-translational processing or modification. Therefore, it is necessary to quantitatively analyze the gene expression profile using proteomic techniques. In the present study, we established a rat model of closed brain injury using Marmarou's weight-drop device, and investigated hippocampal differential protein expression using two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry. A total of 364 protein peaks were detected on weak cation exchange-2 protein chips, including 37 differential protein peaks. 345 protein peaks were detected on immobilized metal affinity capture arrays-Cu, including 12 differential protein peaks Further examination of these differential proteins revealed that glucose-regulated protein and proteasome subunit alpha type 3 expression were significantly upregulated post-injury. These results indicate that brain injury can alter protein expression in the hippocampus, and that glucose-regulated protein and proteasome subunit alpha type 3 are closely associated with the occurrence and development of traumatic brain injury.展开更多
Background Recently, due to the rapid development of proteomic techniques, great advance has been made in many scientific fields. We aimed to use magnetic beads (liquid chip) based matrix-assisted laser desorption/i...Background Recently, due to the rapid development of proteomic techniques, great advance has been made in many scientific fields. We aimed to use magnetic beads (liquid chip) based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) technology to screen distinctive biomarkers for lung adenocarcinoma (adCA), and to establish the diagnostic protein profiles. Methods Using weak cation exchange magnetic beads (MB-WCX) to isolate and purify low molecular weight proteins from sera of 35 lung adCA, 46 benign lung diseases (BLDs) and 44 healthy individuals. The resulting spectra gained by anchor chip-MALDI-TOF-MS were analyzed by ClinProTools and a pattern recognition genetic algorithm (GA). Results In the working mass range of 800-10 000 Da, 99 distinctive peaks were resolved in lung adCA versus BLDs, while 101 peaks were resolved in lung adCA versus healthy persons. The profile gained by GA that could distinguish adCA from BLDs was comprised of 4053.88, 4209.57 and 3883.33 Da with sensitivity of 80%, specificity of 93%, while that could separate adCA from healthy control was comprised of 2951.83 Da and 4209.73 Da with sensitivity of 94%, specificity of 95%. The sensitivity provided by carcinoembryonic antigen (CEA) in this experiment was significantly lower than our discriminatory profiles (P 〈0.005). We further identified a eukaryotic peptide chain release factor GTP-binding subunit (eRF3b) (4209 Da) and a complement C3f (1865 Da) that may serve as candidate biomarkers for lung adCA. Conclusion Magnetic beads based MALDI-TOF-MS technology can rapidly and effectively screen distinctive proteins/polypeptides from sera of lung adCA patients and controls, which has potential value for establishing a new diagnostic method for lung adCA.展开更多
Thirteen extracting solutions of rare-earth metallofullerenes containing La,Ce,Pr,Nd Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm and Yb respectively have been investigated by means of matrix-assisted laser desorpuon/ ionization time-of-f...Thirteen extracting solutions of rare-earth metallofullerenes containing La,Ce,Pr,Nd Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm and Yb respectively have been investigated by means of matrix-assisted laser desorpuon/ ionization time-of-flight mass spectrometry.The influences of the positive-ion/negative-ion mode,laser intensity,ma trix and mass discrimination to the analytical results are studied,based on which the optimal analytical conditions have been determined.The results show that the extracting solutions contain large quantities of rare-earth metallofullerenes besides empty fullerenes.On the basis of comparing their relative intensities,the different structure stabilities and solubilities of metallofullerenes with different rare-earth metals encapsulated into the fullerene cages,as well as some possible reasons to those differences,are discussed.展开更多
Native and methyl-esterified sialylated glycans were analyzed with 2,4,6-trihydroxyacetophenone(THAP)and 2,5-dihydroxybenzoic acid(DHB)as matrix by a matrix-assisted laser desorption/ionization time-of-flight mass...Native and methyl-esterified sialylated glycans were analyzed with 2,4,6-trihydroxyacetophenone(THAP)and 2,5-dihydroxybenzoic acid(DHB)as matrix by a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer(MALDI-TOF MS).High quality negative-ion spectra of commercial sialylated glycan were obtained with THAP as matrix.Detection limit of the glycan was less than 0.1 pmol.After methyl esterification of sialic acid(SA)residue,sialylated glycans were detected sensitively in the positive-ion mode using DHB as matrix.Neutral and sialylated glycans from the mixture of asialofetuin and fetuin were methylesterified and simultaneously recognized in one manipulation.Methyl esterification of SA residue offers a convenient and sensitive way to identify the structure of N-linked glycans for glycan profiling.展开更多
AIM:To investigate the potential of serum peptides as a diagnostic tool for hepatocellular carcinoma(HCC)with bone metastasis.METHODS:Matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-...AIM:To investigate the potential of serum peptides as a diagnostic tool for hepatocellular carcinoma(HCC)with bone metastasis.METHODS:Matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF-MS)was used to characterize the serum peptide profile of HCC patients with bone metastasis.Serum samples from 138 HCC patients(66 cases with and 72 cases without bone metastasis)were randomly assigned into a training set(n=76)and a test set(n=62).Differential serum peptides were examined using ClinProt magnetic bead-based purification followed by MALDITOF-MS.The sequences of differentially expressed serum peptides were identified using liquid chromatography-mass spectrometry.A diagnostic model was established using a learning algorithm of radial basis function neural network verified by a single blind trial.Receiver operating characteristic(ROC)analysis was performed to evaluate the diagnostic power of the established model.RESULTS:Ten peptide peaks were significantly different between HCC patients with or without bone metastasis(P<0.001).Sequences of seven peptides with mass to charge ratios(m/z)of 1780.7,1866.5,2131.6,2880.4,1532.4,2489.8,and 2234.3 were successfully identified.These seven peptides were derived from alpha-fetoprotein,prothrombin,serglycin,isoform2 of inter-alpha-trypsin inhibitor heavy chain H4,isoform 1 of autophagy-related protein 16-2,and transthyretin and fibrinogen beta chains,respectively.The recognition rate and predictive power of a diagnostic model established on the basis of six significant peptides(m/z for these six peptides were 1535.4,1780.7,1866.5,2131.6,2880.4,and 2901.9)were 89.47%and82.89%,respectively.The sensitivity and specificity of this model based upon a single blind trial were 85.29%and 85.71%,respectively.ROC analysis found that the AUC(area under the ROC curve)value was 0.911.CONCLUSION:Our study suggested that serum peptides may serve as a diagnosis tool for HCC bone metastasis.展开更多
Objective To apply two-dimensional electrophoresis and mass spectrometry in the ovary proteome researchMethods Protein extractions from mouse ovaries were run in IPGphor isoelectric focus system with 11 cm and 24 cm I...Objective To apply two-dimensional electrophoresis and mass spectrometry in the ovary proteome researchMethods Protein extractions from mouse ovaries were run in IPGphor isoelectric focus system with 11 cm and 24 cm IPG strips respectively (pH 3~10, 0.3 mm thick), then the protein spots were identified by mass spectrometry.Results The ovary protein exactions separated by two-dimensional electrophoresis have got high resolution, and identifing protein by mass spectrometry was highly efficient and facilitly. These two techniques should facilitate further investigation of female reproduction proteome research.Conclusion These two rapid high resolutions and efficient techniques have a variety of applications foreground in female reproduction proteome pattern research.展开更多
Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 pat...Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 patients with stage Ⅰ lung adenocarcinoma and 17 age-and sex-matched healthy controls,and the serum proteomic profiles were obtained by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Results Compared with healthy control group,two highly expressed potential biomarkers were identified with the relative molecular weights of 6 631.64 Da and 4 964.21 Da. The two best novel protein peaks were automatically chosen for the system training and the development of the constructed model. The constructed model was then used to test an independent set of masked serum samples from 15 lung adenocarcinoma patients and 22 healthy individuals. The analysis yielded a sensitivity of 93.3%,and a specificity of 95.5%. Conclusion These results suggest that MALDI-TOF-MS ProteinChip technology is a quick,convenient,and high-output analyzing method that is capable of selecting several relatively potential biomarkers from the serum of lung adenocarcinoma patients and may have a clinical value in the future,and will provide clues to identifying new serologic biomarkers of lung adenocarcinoma.展开更多
基质辅助激光解吸电离飞行时间质谱(matrix assisted laser desorption ionization time of flight mass spectrometry,MALDI-TOF MS)作为近年来发展的新型食源性致病菌鉴定技术,具有灵敏、准确、检测速度快等优点,该技术为食品病原微...基质辅助激光解吸电离飞行时间质谱(matrix assisted laser desorption ionization time of flight mass spectrometry,MALDI-TOF MS)作为近年来发展的新型食源性致病菌鉴定技术,具有灵敏、准确、检测速度快等优点,该技术为食品病原微生物靶标性监测和食品安全事件应急检验提供了一种高效的鉴别技术参考,在保障民众生命健康和经济社会发展上发挥了重要作用。本文检索了近年来国内外MALDI-TOF MS技术在食源性致病菌检测中的相关研究案例,简要综述了MALDI-TOF MS检测原理、工作流程,影响鉴定结果的主要因素,介绍了MALDI-TOF MS技术应用于食源性致病菌检测中的实际案例,在此基础上分别从参考菌株数据库建设、标准化程序规范等方面对MALDI-TOF MS技术在食源性致病菌检测领域的未来研究方向进行展望,以期为后续食品安全检测及快速监管食源性致病菌污染提供技术支持。展开更多
文摘Introduction Single nucleotide polymorphisms (SNPs) are the most abundant DNA markers in the human genome occurring at a frequency of one in every 500--1000 nucleotides. A variety of methods have been used for the analysis of single nucleotide polymorphisms, including restriction fragment length polymorphism (RFLP), direct sequencing by using laser-induced fluorescence detectionTM, fluorescence energy transfer, MALDI-TOF MS combined with primer extension or invasive cleavage, and fluorescence polarization. During the past two decades, mass spectrometry has become a very popular tool in the analysis of biomolecules and is perfectly suited to the analysis of single nucleotide polymorphisms (SNPs) due to its speed, low cost, and accuracy. In this work, we used MALDI TOF mass spectrometry to detect the fragments of restriction endonuclease hydrolysis of PCR products flanking a SNP located at paraoxonase 1(Q192R). Compared with electrophoresis, this method requires less time of analysis and possess a higher accuracy.
文摘Matrix-assisted Laser Desorption/Ionization with Time-of-flight Mass Spectrometry (MALDI-TOFMS) was investigated as a method for the rapid identifica-tion of species. Current demand in microbial identi-fication is how to compare unknown strains to the known one quickly, semi-automatically and accurately. In this paper, we present a software tool that allows flexibly microbial matching in a user-friendly way, by letting the users to customize comparison parameters including: in vitro transcription enzyme, mass tolerance,minimum fragment length, intensity threshold and corresponding weights. We provide three spectral scoring functions to compute the affin-ity between the species. Therefore, the precision of microbial comparison increases. To test and verify this tool, we employed experimental spectral data based on MALDI-TOFMS and the gene sequences of E.coli and Salmonella. This software is written in Java for cross-platform intention.
基金the National Natural Science Foundation of China,No. 30471934
文摘Gene expression profile changes in brain regions following traumatic brain injury at the gene level cannot sufficiently elucidate gene expression time, expression amount, protein post-translational processing or modification. Therefore, it is necessary to quantitatively analyze the gene expression profile using proteomic techniques. In the present study, we established a rat model of closed brain injury using Marmarou's weight-drop device, and investigated hippocampal differential protein expression using two-dimensional gel electrophoresis and surface-enhanced laser desorption ionization-time of flight-mass spectrometry. A total of 364 protein peaks were detected on weak cation exchange-2 protein chips, including 37 differential protein peaks. 345 protein peaks were detected on immobilized metal affinity capture arrays-Cu, including 12 differential protein peaks Further examination of these differential proteins revealed that glucose-regulated protein and proteasome subunit alpha type 3 expression were significantly upregulated post-injury. These results indicate that brain injury can alter protein expression in the hippocampus, and that glucose-regulated protein and proteasome subunit alpha type 3 are closely associated with the occurrence and development of traumatic brain injury.
基金This work was supported by grants from the National Natural Science Foundation of China (No. 30570795) and Program for New Century Excellent Talents in University (No. NECT-06-0845) and the Program in Science and Technology of Xi'an, Shaanxi Province (No. S F08009(1)).Acknowledgement: We are grateful to HU Xiao-hui for the technical guidance.
文摘Background Recently, due to the rapid development of proteomic techniques, great advance has been made in many scientific fields. We aimed to use magnetic beads (liquid chip) based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) technology to screen distinctive biomarkers for lung adenocarcinoma (adCA), and to establish the diagnostic protein profiles. Methods Using weak cation exchange magnetic beads (MB-WCX) to isolate and purify low molecular weight proteins from sera of 35 lung adCA, 46 benign lung diseases (BLDs) and 44 healthy individuals. The resulting spectra gained by anchor chip-MALDI-TOF-MS were analyzed by ClinProTools and a pattern recognition genetic algorithm (GA). Results In the working mass range of 800-10 000 Da, 99 distinctive peaks were resolved in lung adCA versus BLDs, while 101 peaks were resolved in lung adCA versus healthy persons. The profile gained by GA that could distinguish adCA from BLDs was comprised of 4053.88, 4209.57 and 3883.33 Da with sensitivity of 80%, specificity of 93%, while that could separate adCA from healthy control was comprised of 2951.83 Da and 4209.73 Da with sensitivity of 94%, specificity of 95%. The sensitivity provided by carcinoembryonic antigen (CEA) in this experiment was significantly lower than our discriminatory profiles (P 〈0.005). We further identified a eukaryotic peptide chain release factor GTP-binding subunit (eRF3b) (4209 Da) and a complement C3f (1865 Da) that may serve as candidate biomarkers for lung adCA. Conclusion Magnetic beads based MALDI-TOF-MS technology can rapidly and effectively screen distinctive proteins/polypeptides from sera of lung adCA patients and controls, which has potential value for establishing a new diagnostic method for lung adCA.
基金Project supported by the National Natural Science Foundation of China
文摘Thirteen extracting solutions of rare-earth metallofullerenes containing La,Ce,Pr,Nd Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm and Yb respectively have been investigated by means of matrix-assisted laser desorpuon/ ionization time-of-flight mass spectrometry.The influences of the positive-ion/negative-ion mode,laser intensity,ma trix and mass discrimination to the analytical results are studied,based on which the optimal analytical conditions have been determined.The results show that the extracting solutions contain large quantities of rare-earth metallofullerenes besides empty fullerenes.On the basis of comparing their relative intensities,the different structure stabilities and solubilities of metallofullerenes with different rare-earth metals encapsulated into the fullerene cages,as well as some possible reasons to those differences,are discussed.
基金Supported by the National Natural Science Foundation of China(30800193)Grant from Centre for International Mobility(CIMO),Finland
文摘Native and methyl-esterified sialylated glycans were analyzed with 2,4,6-trihydroxyacetophenone(THAP)and 2,5-dihydroxybenzoic acid(DHB)as matrix by a matrix-assisted laser desorption/ionization time-of-flight mass spectrometer(MALDI-TOF MS).High quality negative-ion spectra of commercial sialylated glycan were obtained with THAP as matrix.Detection limit of the glycan was less than 0.1 pmol.After methyl esterification of sialic acid(SA)residue,sialylated glycans were detected sensitively in the positive-ion mode using DHB as matrix.Neutral and sialylated glycans from the mixture of asialofetuin and fetuin were methylesterified and simultaneously recognized in one manipulation.Methyl esterification of SA residue offers a convenient and sensitive way to identify the structure of N-linked glycans for glycan profiling.
基金Supported by the Medical Guidance Program of the Science and Technology Commission of Shanghai Municipality,No.10411962400
文摘AIM:To investigate the potential of serum peptides as a diagnostic tool for hepatocellular carcinoma(HCC)with bone metastasis.METHODS:Matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF-MS)was used to characterize the serum peptide profile of HCC patients with bone metastasis.Serum samples from 138 HCC patients(66 cases with and 72 cases without bone metastasis)were randomly assigned into a training set(n=76)and a test set(n=62).Differential serum peptides were examined using ClinProt magnetic bead-based purification followed by MALDITOF-MS.The sequences of differentially expressed serum peptides were identified using liquid chromatography-mass spectrometry.A diagnostic model was established using a learning algorithm of radial basis function neural network verified by a single blind trial.Receiver operating characteristic(ROC)analysis was performed to evaluate the diagnostic power of the established model.RESULTS:Ten peptide peaks were significantly different between HCC patients with or without bone metastasis(P<0.001).Sequences of seven peptides with mass to charge ratios(m/z)of 1780.7,1866.5,2131.6,2880.4,1532.4,2489.8,and 2234.3 were successfully identified.These seven peptides were derived from alpha-fetoprotein,prothrombin,serglycin,isoform2 of inter-alpha-trypsin inhibitor heavy chain H4,isoform 1 of autophagy-related protein 16-2,and transthyretin and fibrinogen beta chains,respectively.The recognition rate and predictive power of a diagnostic model established on the basis of six significant peptides(m/z for these six peptides were 1535.4,1780.7,1866.5,2131.6,2880.4,and 2901.9)were 89.47%and82.89%,respectively.The sensitivity and specificity of this model based upon a single blind trial were 85.29%and 85.71%,respectively.ROC analysis found that the AUC(area under the ROC curve)value was 0.911.CONCLUSION:Our study suggested that serum peptides may serve as a diagnosis tool for HCC bone metastasis.
文摘Objective To apply two-dimensional electrophoresis and mass spectrometry in the ovary proteome researchMethods Protein extractions from mouse ovaries were run in IPGphor isoelectric focus system with 11 cm and 24 cm IPG strips respectively (pH 3~10, 0.3 mm thick), then the protein spots were identified by mass spectrometry.Results The ovary protein exactions separated by two-dimensional electrophoresis have got high resolution, and identifing protein by mass spectrometry was highly efficient and facilitly. These two techniques should facilitate further investigation of female reproduction proteome research.Conclusion These two rapid high resolutions and efficient techniques have a variety of applications foreground in female reproduction proteome pattern research.
文摘Objective To identify specific biomarkers that could improve early diagnosis of lung adenocarcinoma using matrix-assisted laser desorption/ionization (MALDI) technology. Methods Serum samples were isolated from 17 patients with stage Ⅰ lung adenocarcinoma and 17 age-and sex-matched healthy controls,and the serum proteomic profiles were obtained by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. Results Compared with healthy control group,two highly expressed potential biomarkers were identified with the relative molecular weights of 6 631.64 Da and 4 964.21 Da. The two best novel protein peaks were automatically chosen for the system training and the development of the constructed model. The constructed model was then used to test an independent set of masked serum samples from 15 lung adenocarcinoma patients and 22 healthy individuals. The analysis yielded a sensitivity of 93.3%,and a specificity of 95.5%. Conclusion These results suggest that MALDI-TOF-MS ProteinChip technology is a quick,convenient,and high-output analyzing method that is capable of selecting several relatively potential biomarkers from the serum of lung adenocarcinoma patients and may have a clinical value in the future,and will provide clues to identifying new serologic biomarkers of lung adenocarcinoma.
文摘基质辅助激光解吸电离飞行时间质谱(matrix assisted laser desorption ionization time of flight mass spectrometry,MALDI-TOF MS)作为近年来发展的新型食源性致病菌鉴定技术,具有灵敏、准确、检测速度快等优点,该技术为食品病原微生物靶标性监测和食品安全事件应急检验提供了一种高效的鉴别技术参考,在保障民众生命健康和经济社会发展上发挥了重要作用。本文检索了近年来国内外MALDI-TOF MS技术在食源性致病菌检测中的相关研究案例,简要综述了MALDI-TOF MS检测原理、工作流程,影响鉴定结果的主要因素,介绍了MALDI-TOF MS技术应用于食源性致病菌检测中的实际案例,在此基础上分别从参考菌株数据库建设、标准化程序规范等方面对MALDI-TOF MS技术在食源性致病菌检测领域的未来研究方向进行展望,以期为后续食品安全检测及快速监管食源性致病菌污染提供技术支持。