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

"Target fishing" strategy was used to investigate the direct targets and mechanism of Shouhui Tongbian Capsules on relaxing bowel. Magnetic beads cross-linked with the chemical constituents from Shouhui Tongbian Capsules were prepared. The potential target proteins were captured from the total protein lysates of rat intestine using the beads. The captured proteins were further identified by LC-MS/MS, and the associated pathways were analyzed by Cytoscape. RESULTS:: showed that 138 potential target proteins were identified, which were involved in eight signaling pathways, including tricarboxylic acid cycle, pyrimidine metabolism, sulfur metabolism, fatty acid degradation, alanine/aspartate/glutamate metabolism, arginine/proline metabolism, valine/leucine/isoleucine degradation, and β-alanine metabolism. Taken together, Shouhui Tongbian Capsules may exert relaxing bowel effect by acting on multiple signaling pathways to promote intestinal gurgling, inhibit inflammation, as well as improve intestinal barrier function, intestinal water secretion, and intestinal flora.
Animals ; Capsules ; Chromatography, Liquid ; Intestines ; Leucine ; Rats ; Tandem Mass Spectrometry

In this experiment, an ultra-high performance liquid chromatographytandem triple quadrupole mass spectrometry was established for the determination of caffeine in commercially available Ginkgo Folium. The samples were extracted by ultrasonic method with methanol, and separated on Waters CORTECS T3 column(2.1 mm×100 mm, 2.7 μm), with mobile phase of 0.1% formic acid solution-0.1% formic acid acetonitrile solution for gradient elution, at flow rate of 0.3 mL·min~(-1); column temperature of 30 ℃, and injection volume of 2 μL. Mass spectrometry was conducted at ESI~+ multiple reaction monitoring(MRM) mode; quantitative analysis was conducted with external standard method. The results showed that in the range of 0.099 6-9.96 ng·mL~(-1), there was a good linear relationship between the mass concentration of caffeine and the peak area, R~2=0.999; the average recovery was 84.51%, with RSD of 6.2%. The results of precision, repeatability and stability showed that the RSD was 5.1%, 5.9%, 7.2%, respectively. The content range of caffeine in 10 batches of Ginkgo Folium was 1.52-60.86 μg·kg~(-1). In conclusion, this method is accurate, reliable and reproducible, which provides a reference for the safety study of Ginkgo Folium.
Caffeine ; Chromatography, High Pressure Liquid ; Ginkgo biloba ; Tandem Mass Spectrometry

This study is to clarify the composition and content differences of water-soluble nutrients in Lycium barbarum leaves(LBLs) from different areas. The total polysaccharides, free monosaccharides and oligosaccharides, nucleosides and amino acids in 35 batches of LBLs were analyzed with use of spectrophotometry, HPLC-ELSD and UPLC-MS/MS. The results showed that LBLs contained abundant polysaccharides, fructose, glucose, sucrose and maltose, with an average contents of 39.07, 12.69, 8.99, 17.44, 8.32 mg·g~(-1), respectively. Besides, eight nucleosides and twelve amino acids were detected in LBLs, and their average total contents were 54.95, 336.9 μg·g~(-1). Principal component analysis(PCA) and partial least squares discrimination analysis(PLS-DA) of carbohydrate, nucleoside and amino acid showed that the water-soluble nutrients of the samples from Qinghai Province were significantly different from those from other areas mainly in asparagine, proline, glutamine, sucrose, adenine and guanosine. In this study, the compositions and contents of water-soluble nutrients in LBLs were preliminarily clarified, which provided basis for further development and utilization of LBLs resoures.
Chromatography, Liquid ; Lycium ; Nutrients ; Plant Leaves ; Tandem Mass Spectrometry ; Water

Aceria pallida is one of the most common pests in the main production areas of Lycium barbarum in China. The mite mainly feeds on foliage, leading to local tissue deformation and formation of massive galls, which seriously affects the growth and yield of L. barbarum. However, little is known about the influence of galling organisms on plant primary and secondary metabolism. In order to compare the metabolites differences between healthy and the mite infested leaves of wolfberry, and provide a scientific basis for the development and utilization of the galled leaves, L. barbarum seedlings were infested with A. pallida artificially in the laboratory, the metabolites of L. barbarum leaves were determined by LC-MS/MS. Our results showed that the leaves were rich in amino acids and flavonoid compounds. A total of 204 compounds from 16 classes were detected in L. barbarum leaves based on LC-MS/MS. The primary metabolites are mainly amino acids, and the secondary metabolites are mainly organic acids and flavonoids. The content of the metabolite in the leaves of L. barbarum was significantly affected by the mite, 30 metabolites such as flavonoids and phenylpropanoids were significantly changed, 21 metabolites were up-regulated and 9 metabolites were down-regulated significantly. There were 8 compounds which has pharmacological and biological activity, such as eriodictyol, isorhamnetin-3-O-neohesperidoside and scopoletin up-regulated significantly. Based on the above findings, we suggest that the galled leaves of L.barbarum have a potential to be developed in the future.
China ; Chromatography, Liquid ; Lycium ; Metabolomics ; Plant Leaves ; 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