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

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

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

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

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.

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

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.

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

To reveal the effect of plant growth regulator GA₃ and DPC on the active components and its possible mechanism of Lonicera japonica. GA and DPC were applied at the stage of flower bud differentiation, and the content of active ingredients was measured by LC-MS-MS, the content of endogenous hormones were measured by ELISA, and the expression of key enzyme enes expression was determined by qRT-PCR. The level of endogenous hormone GA₃, IAA, ZR, DHZR and iPA in the GA treatment group was significantly improved, the expression of C4H1, C4H2, 4CL1 and HQT2 were also significantly increased. The content of chlorogenic acid, luteolin, luteoloside, isoquercetin and caffeic acid increased significantly. Spraying DPC did not affect or inhibit the accumulation of active components of L. japonica. Spraying GA can increase the content of endogenous GA₃, thus enhance the expression of C4H1, C4H2, 4CL1 and HQT2, and then increase the content of chlorogenic acid and luteolin.
Chlorogenic Acid ; Lonicera ; Plant Growth Regulators ; Tandem Mass Spectrometry

OBJECTIVE: To explore the metabolic characteristics and metabolic markers of WBC-depleted RBCs in MAP preservation solution and to analyzed the metabolic profile of RBC in MAP preservation solution by using metabolomics. METHODS: The changes of metabolitcs in 10 U WBC-depleted RBC suspension at 3-different storage period (D 0, D 14 and D 35) were detected by using the UPLC-MS/MS, the charaeteristic ions and metabolic markers of RBC stored in preservation sblution for 0 d, 14 d and 35 days were analyzed by using the principal component analysis(PCA). RESULTS: The number of characteristic ions in RBC and supernatant extracts detected during the initial, middle and final storage could be clearly distinguiseed. The 5 metabolism-related substamces such as lact-c acid, nicotinamide, glucose, 5-htdroxyproline and malic acid showed statistically significant difference in 3 storage period. CONCLUSION The UPLC-MS/MS method combined with statistical analysis of multivariate data can be used to study the metabolic characteristics of RBC, the different metabolites of RBC in different storage stages can be used as the potential markers for evaluation of guality of RBC in storag period. The results of this study provide a basis for studing the RBC guality changes in storage period.
Blood Preservation ; Chromatography, Liquid ; Erythrocytes ; Metabolome ; Tandem Mass Spectrometry