Proteomics is one of the most important functional genomics research in the post-genomic era, which is closely related to medical biology, chemistry, physics, information science and modern technology. Through review research progress of some important proteomics, a proteomics special issue is published so as to find problems, explore the possible applications and outlook the development prospects of proteomics. The special issue consists of reviews and original papers, mainly involving in the following aspects, i) proteomics about different species such as humans, mammals, prokaryotes and actinobacterial; ii) proteomics methodology and techniques including tandem mass spectrometry analysis, film (urimem) preservation of urine protein, quantitative proteomic analysis and meta analysis; iii) function and application of proteome such as spider (Latrodectus tredecimguttatus) toxins proteome, protein phosphorylation proteome, oocytes and early embryos proteomes, liver fibrosis proteome, drug-resistant mycobacterium tuberculosis proteome, etc.
Animals ; Humans ; Proteome ; Proteomics ; Tandem Mass Spectrometry

In this study,liquiritigenin sulfonation was characterized using recombinant human sulfotransferases( SULTs). The chemical structure of liquiritigenin sulfate was determined by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry( UPLC-Q-TOF-MS/MS). Then model fitting and parameter estimation were performed using the Graphpad Prism V5 software. Various SULT enzymes( SULT1 A1,1 A2,1 A3,1 B1,1 C2,1 C4,1 E1 and 2 A1) were able to catalyze the formation of liquiritigenin-7-O-sulfate. Sulfonation of liquiritigenin-7-hydroxy( 7-OH) by these eight SULT enzymes consistently displayed the classical Michaelis-Menten profile. According to the intrinsic clearance( CLint) value,the sulfonation rates of liquiritigenin-7-OH by expressed SULT enzymes followed the following rank order: SULT1 C4 > SULT1 A3 > SULT1 E1 > SULT1 A1 > SULT1 A2 > SULT1 B1 >SULT1 C2>SULT2 A1. Further,liquiritigenin-7-O-sulfonation was significantly correlated with the SULT1 A3 protein levels( P<0. 05).Then,human embryonic kidney( HEK) 293 cells over expressing SULT1 A3( named as HEK-SULT1 A3 cells) were conducted. As a result,liquiritigenin-7-O-sulfate( L-7-S) was rapidly generated upon incubation of the cells with liquiritigenin. Consistent with SULT1 A3,sulfonation of liquiritigenin-7-OH in HEK-SULT1 A3 cells also followed the Michaelis-Menten kinetics. The derived Vmaxvalues was( 0. 315±0. 009) μmol·min-1·g-1,Kmwas( 7. 04±0. 680) μmol·L^-1,and CLintwas( 0. 045±0. 005) L·min^-1·g^-1. Moreover,the sulfonation characters of liquiritigenin( 7-OH) in SULT1 A3 were strongly correlated with that in HEK-SULT1 A3 cells( P<0. 001).The results indicated that HEK-SULT1 A3 cells have shown the catalytic function of SULT1 A3 enzymes. In conclusion,liquiritigenin was subjected to efficient sulfonation,and SULT1 A3 enzyme plays an important role in the sulfonation of liquiritigenin-7-OH. Significant sulfonation should be the main reason for the low bioavailability of liquiritigenin. In addition,HEK-SULT1 A3 cells were conducted and successfully used to evaluate liquiritigenin sulfonation,which will provide an appropriate tool to accurately depict the sulfonation disposition of liquiritigenin in vivo.
Arylsulfotransferase ; Flavanones/metabolism* ; Humans ; Tandem Mass Spectrometry

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) combines the advantages of high separation ability of chromatography and high selectivity, specificity and sensitivity of mass spectrometry, making it one of the most vibrant new technologies in the field of clinical testing. However, the analytical performance is often limited by the characteristics of the sample to be measured. Due to the limited anti-contamination capability of the mass spectrometer, biological samples need to be properly pre-processed to effectively improve the detection performance and achieve accurate detection. The main function of pre-treatment is to selectively separate the target analyte from the biological matrix to reduce interference from other matrix components. At the same time, the target analytes can be concentrated and enriched to improve the analytical sensitivity. At present, there are many kinds of clinical sample pre-treatment methods, and several methods are time-consuming and cumbersome, which brings difficulties to laboratory personnel in method selection, development and standardized operation. Therefore, the purpose of this consensus is to provide guidance for the establishment of laboratory methods and facilitate the standardized development of clinical mass spectrometry measurement.
Humans ; Chromatography, Liquid ; Consensus ; Tandem Mass Spectrometry

OBJECTIVEWe established a method of UPLC-MS/MS that was to detect fifteen precursors of perfluoroalkyl sulfonates (PFSA) and perfluoroalkyl carboxylates (PFCA) in serum.

METHODSBriefly, TBAS solution was added to sera, then the mixed solution was extracted with aliquots of MTBE. The MTBE aliquots were combined, evaporated to dryness under nitrogen, and reconsituted in 0.25 ml of methanol and water (1:1). Then the reconstituted solution through 0.2 µm nylon syringe filter was collected. Chromatographic separation was performed using a Waters ACQUITY (TM) BEH ¹⁸C column (50 mm × 2.1 mm × 1.7 mm). Analyte quantitation was performed in the negative electrospray ionization mode and multiple reaction monitoring (MRM).

RESULTSThree target substances, 6: 6PFPi, 6: 8PFPi, 8: 8PFPi, were externally confirmed by standard addition. Rates of recovery for these three chemicals were from 41.01% to 112.13% in two standard levels. And the relative standard deviations (RSD) were lower than 11.63% and higher than 1.80%. The other twelve substances were quantified with internal standard. Moreover in two standard levels, rate of recovery for these chemicals ranged from 70.25% to 127.51%. And RSD were more than 1.23% and less than 15.45%. And the corresponding limit of detection (LOD) and limit of quantitation (LOQ) for all target substances were 0.1-5.0 pg/ml and 0.2-10.0 pg/ml. Then we detected these target substances in ten different human serum samples. The levels of few substances were higher than LOD. And the ranges of FOSA-M, N-EtFOSA-M, N-MeFOSAA, N-EtFOSAA were respectively < LOD-0.94 pg/ml, < LOD-10.08 pg/ml, < LOD-6.74 pg/ml, < LOD-1.04 pg/ml.

CONCLUSIONThe method, with high sensitivity and accuracy, could meet the actual testing requirements.

A rapid, sensitive and convenient LC-MS/MS method was developed for the determination of γ-aminobutyric acid (GABA) in human plasma. d2-γ-Aminobutyric acid (d2-GABA) was synthesized as internal standard (IS). After extraction from human plasma by protein precipitation with acetonitrile, all analytes were separated on a Luna HILIC column (100 mm x 3.0 mm, 3 μm) using an isocratic mobile phase of water: acetonitrile: formic acid (20 : 80 : 0.12) with a flow rate of 0.5 mL x min(-1). Acquisition of mass spectrometric data was performed in multiple reaction monitoring mode (MRM) in positive electrospray ionization using the transitions of m/z 104 --> 69 for GABA and m/z 106 --> 71 for d2-GABA. The method was linear in the concentration range of 5.00 to 1 000 ng x mL(-1). The intra- and inter-day precisions were within 9.9%, and accuracy ranged from 99.1% to 104%, within the acceptable limit across all concentrations. The method was successfully applied to a pharmacokinetic study of GABA tablets in healthy Chinese volunteers.
Chromatography, Liquid ; Humans ; Tandem Mass Spectrometry ; gamma-Aminobutyric Acid ; blood

OBJECTIVETo investigate the differences of metabolic pathways of leucocyte-deplated RBCs prepared by using lipid whole blood and nomal blood during routine storage so as to provide some reference for clinical blood use.

METHODSTwenty U whole blood from 20 donors, including 10 U lipid blood and 10 U normal whole blood, were selected for preparing leukodepleted red blood cells, red blood cells were taken from storage bags on day 0, 14 and 35, respectively. Metabolites in the red blood cells were analyzed, red blood cell metabolic extracts were detected by UPLC-MS/MS. The metabolite data of RBC from 2 groups were analyzed by SIMCA-P 13.0 software using OPLS-DA and by SPSS 19.0 using Mann-Whitney U test. Difference of metabolic pathways was described according to different metabolites.

RESULTSThe glucose, adenine, pyruvic acid, GSH, GSSG and niacinamide levels on day 0 in lipid RBCs were higher than those in the control group(P<0.05). The glucose, pyruvic acid and GSH levels on day 14 in lipid RBCs were lower than those in the control group (P<0.05), and the levels of adenine, GSSG and niacinamide were higher than that in the control group (P<0.05). The glucose level on day 0 was lower than that in the control group (P<0.05), and the levels of adenine and niacinamide were higher than those in the control group (P<0.05). but the pyruvic acid, GSH and GSSG levels were not significantly different between 2 groups (P>0.05).

CONCLUSIONCompared with the normal red blood cells, the energy metabolism pathway decreases in lipid red blood cells within the storage period and pentose phosphate pathway increases.

OBJECTIVE: To screen the differentially expressed proteins at the early stage of K562 cells treated with meisoindigo by using tandem mass tags (TMT)-based proteomics technology, and to explore the mechanism for meisoindigo-inducing apoptosis. METHODS: The half inhibitory concentration (IC) of mesoindigo on K562 cells was determined by CCK8. The flow cytometry was used to assay the apoptosis of K562 cells treated by meisoindigo or DMSO. Total proteins were extracted from the cells treated with 0.2% DMSO (control) or 20 μmol/L meisoindigo (Test) for 2 hours. Then, the TMT-labeling HPLC-MS/MS was used to identify and quantify the peptides and their abundance, all the tests were repeated for 3 times. The Mascot software was used to identify the proteins; the GO annotations, enrichment and cluster analysis were used to analyze the differentially expressed proteins. RESULTS: Meisoindigo-induced K562 cell apoptosis in a dose-dependent manner (r=0.98), 5 544 proteins were identified, 4792 of which were quantified. The protein with expression difference>1.5-folds in Test group accoanted for 8, out of which the expression of 4 proteins were up-regulated and 4 were down-regulated. The differentially expressed proteins mainly associated with reactive oxygen species (ROS). CONCLUSION Several proteins including DDIT4 were found to have dramatic changes in the early stage of K562 cells treated with meisoindigo by using quantitative proteomics technology. The ROS metabolic process may play important roles in meisoindigo-inducing apoptosis of K562 cells.
Apoptosis ; Humans ; Indoles ; K562 Cells ; Proteomics ; Tandem Mass Spectrometry

Based on metabolomics,the effect of Magnolia officinalis before and after " sweating" on gastrointestinal motility disorder( rat) was compared. To study the mechanism of M. officinalis " sweating" increased the efficacy and reduced the toxicity. The rat model of gastrointestinal motility disorder was established by intraperitoneal injection of L-arginine. Pharmacodynamic indexes were relative residual rate of gastric pigment and intestinal propulsion ratio in rats. LC-MS metabolomics and multivariate statistical analysis were used to screen and identify biomarkers associated with gastrointestinal motility disorders,and MetPA database was used to analyze related metabolic pathways. The results showed that M. officinalis could improve gastrointestinal motility disorder whether it " sweating" or not,and the effect of " sweating" M. officinalis was stronger than that of " no sweating" M. officinalis. The metabolites of the experimental groups could be distinguished distinctly,and 15 different compounds and 17 related pathways were identified preliminarily. The mechanism of M. officinalis might be to improve gastrointestinal motility disorder by increasing the content of L-glutamate in the metabolic pathway of alanine,aspartate and glutamate and protecting gastrointestinal barrier. Before " sweating",M. officinalis could reduce taurine through metabolism of taurine and taurine and biosynthetic pathway of primary bile acid,increase the content of deoxycholic acid in glycine goose,and increase the risk of liver and kidney injury. After " sweating",M. officinalis could enhance gastrointestinal motility by increasing the contents of L-tryptophan and serotonin in the tryptophan pathway,and avoid the production of harmful metabolites to achieve synergistic and detoxifying effect.
Animals ; Gastrointestinal Motility ; Magnolia ; Metabolomics ; Rats ; Sweating ; Tandem Mass Spectrometry

The present study is to establish a method for simultaneous determination of 50 kinds of pesticides in Angelicae Sinensis Radix by using liquid chromatography tandem mass spectrometry. The forbidden,restricted and customary pesticides were picked out as detecting indexes according to the principals of risk management. The factors affecting the extraction,purification,and detection were optimized,and the final condition was established as follows: the samples were extracted with acetonitrile. The separation of target compounds were performed by liquid column,and quantitative analysis was carried out by LC-MS/MS with MRM model. The calibration curves were linear in the range of 1-100 μg·L~(-1) with correction coefficients of greater than 0. 990. The recoveries of more than 93. 9%pesticides were ranged from 60% to 140% at three spiked levels. The detecting indexes in the method cover most forbidden and restricted pesticides,which is meaningful for the safety supervision of the Angelicae Sinensis Radix. With the advantage of rapidness and accuracy,this method can be used for routine determination of multi-pesticides in Angelicae Sinensis Radix.
Chromatography, Liquid ; Pesticide Residues ; Pesticides ; chemistry ; Tandem Mass Spectrometry

Pancreatic lipase (PL) inhibitors were firstly screened from Prunella vulgaris with PL immobilized on carboxylic acid-terminated magnetic nanoparticles, then these possible inhibitors were identified by LC-MS/MS and mixed standards. Finally, their inhibitory effects and types on PL were tested by p-nitrophenol method. The results showed that four PL inhibitors were screened out from P. vulgaris and confirmed by LC-MS/MS and mixed standards. The IC₅₈ and inhibition types were as follows: caffeic acid [(252.3±3.6) mg·L⁻¹, anti-competitive inhibition], rutin [(91.2±1.6)mg·L⁻¹, competitive inhibition], hesperidin [(31.5±4.4) mg·L⁻¹, competitive inhibition] and ursolic acid [(41.3±2.2) mg·L⁻¹, competitive inhibition]. Their inhibitive types and abilities on PL were related to their molecular size, hydrophobicity and the number of hydrogen bond with PL triplet.
Chromatography, Liquid ; Lipase ; Plant Extracts ; Prunella ; Tandem Mass Spectrometry