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1.
Front Chem ; 9: 707235, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34485242

RESUMO

HKU1 is a human beta coronavirus and infects host cells via highly glycosylated spike protein (S). The N-glycosylation of HKU1 S has been reported. However, little is known about its O-glycosylation, which hinders the in-depth understanding of its biological functions. Herein, a comprehensive study of O-glycosylation of HKU1 S was carried out based on dual-functional histidine-bonded silica (HBS) materials. The enrichment method for O-glycopeptides with HBS was developed and validated using standard proteins. The application of the developed method to the HKU1 S1 subunit resulted in 46 novel O-glycosylation sites, among which 55.6% were predicted to be exposed on the outer protein surface. Moreover, the O-linked glycans and their abundance on each HKU1 S1 site were analyzed. The obtained O-glycosylation dataset will provide valuable insights into the structure of HKU1 S.

2.
Se Pu ; 39(9): 989-997, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34486838

RESUMO

Ziziphi Spinosae Semen is the dried seeds of Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou, and its extract has broad application prospects in the development of sleep-aid functional foods. However, the quality parameters of Ziziphi Spinosae Semen extracts currently available in the market are not uniform and there is a lack of unified standards. Therefore, it is important to establish an accurate and comprehensive method for quality evaluation. In view of the problems that the UV responses of flavonoids and saponins in the Ziziphi Spinosae Semen extracts vary dramatically and the saponin content in Ziziphi Spinosae Semen water extract is very low, high performance liquid chromatography (HPLC) was used to establish the fingerprint and quantify spinosin. The separation was carried out on a Waters XSelect HSS C18 column (250 mm×4.6 mm, 5 µm), and the mobile phase was acetonitrile-0.1% (v/v) phosphoric acid aqueous solution for gradient elution. The eight common peaks in the fingerprint of the Ziziphi Spinosae Semen extracts, identified by HPLC-quadrupole time-of-flight mass spectrometry, were attributed to flavonoids by reference substance identification, literature comparison, and high-resolution mass spectrometry data analysis. Semi-quantitative analysis of seven flavonoids and quantitative analysis of spinosin were conducted using the established HPLC quantitative fingerprint. The contents of jujuboside A and jujuboside B were determined by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry. Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C18 column (50 mm×2.1 mm, 1.7 µm) by gradient elution using a mobile phase of acetonitrile-0.1%(v/v) formic acid aqueous solution. The target compounds were analyzed in multiple reaction monitoring mode with positive electrospray ionization. The semi-quantitative and quantitative data of the above-mentioned 10 components are displayed in the form of radar. Using the above methods, three batches of Ziziphi Spinosae Semen water extracts prepared in the laboratory and 15 batches of extract samples obtained from 15 suppliers were analyzed and compared. The results showed that although the raw materials of three batches of Ziziphi Spinosae Semen water extracts prepared in the laboratory were from different enterprises, the overall difference was not significant. However, the component contents of the samples provided by different manufacturers were greatly different, suggesting that there are some problems associated with the different manufacturers, such as dilution of excipients, adulteration of Ziziphi Mauritianae Semen, alcohol extraction, purification, and enrichment. For example, the representative composition contents in the Ziziphi Spinosae Semen extracts obtained from manufacturers B, C, E, F, G, H, I, and O were low, which were approximately 1/10 of corresponding contents in the normal water extracts prepared in the laboratory. It is speculated that to reduce the unit price of the product, the manufacturer used fewer raw materials or a large number of auxiliary materials to dilute the Ziziphi Spinosae Semen extracts. The contents of some flavonoids in the Ziziphi Spinosae Semen extract from manufacturer N were slightly higher than that in the self-preparation Ziziphi Spinosae Semen water extract, but it did not contain jujuboside A; thus, it was speculated that the Ziziphi Mauritianae Semen might be used for extraction. The contents of 10 components in the Ziziphi Spinosae Semen extract obtained from manufacturer D were all higher than the corresponding ones in the self-preparation Ziziphi Spinosae Semen water extract. Combined with the quality label of total saponin content > 20% and poor water solubility, it was speculated that the product might be prepared by alcohol extraction or purified and enriched by using resin. These results provided the basis for the enterprise to establish internal control quality standards for Ziziphi Spinosae Semen extracts and to select qualified suppliers.


Assuntos
Medicamentos de Ervas Chinesas , Espectrometria de Massas em Tandem , Cromatografia Líquida de Alta Pressão , Sementes , Sêmen
3.
J Ethnopharmacol ; 280: 114488, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34358653

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese medicine (TCM) has a long history in the prevention and treatment of pandemics. The TCM formula Lung Cleansing and Detoxifying Decoction (LCDD), also known as Qing Fei Pai Du Decoction, has been demonstrated effective against Coronavirus Disease 2019 (COVID-19). AIM OF THE STUDY: This work aimed to elucidate the active ingredients, targets and pathway mechanism of LCDD related to suppression of inflammatory, immunity regulation and relaxation of airway smooth muscle for the treatment of COVID-19. MATERIALS AND METHODS: Mining chemical ingredients reported in LCDD, 144 compounds covering all herbs were selected and screened against inflammatory-, immunity- and respiratory-related GPCRs including GPR35, H1, CB2, B2, M3 and ß2-adrenoceptor receptor using a label-free integrative pharmacology method. Further, all active compounds were detected using liquid chromatography-tandem mass spectrometry, and an herb-compound-target network based on potency and content of compounds was constructed to elucidate the multi-target and synergistic effect. RESULTS: Thirteen compounds were identified as GPR35 agonists, including licochalcone B, isoliquiritigenin, etc. Licochalcone B, isoliquiritigenin and alisol A exhibited bradykinin receptor B2 antagonism activities. Atractyline and shogaol showed as a cannabinoid receptor CB2 agonist and a histamine receptor H1 antagonist, respectively. Tectorigenin and aristofone acted as muscarinic receptor M3 antagonists, while synephrine, ephedrine and pseudoephedrine were ß2-adrenoceptor agonists. Pathway deconvolution assays suggested activation of GPR35 triggered PI3K, MEK, JNK pathways and EGFR transactivation, and the activation of ß2-adrenoceptor mediated MEK and Ca2+. The herb-compound-target network analysis found that some compounds such as licochalcone B acted on multiple targets, and multiple components interacted with the same target such as GPR35, reflecting the synergistic mechanism of Chinese medicine. At the same time, some low-abundance compounds displayed high target activity, meaning its important role in LCDD for anti-COVID-19. CONCLUSIONS: This study elucidates the active ingredients, targets and pathways of LCDD. This is useful for elucidating multitarget synergistic action for its clinical therapeutic efficacy.


Assuntos
Técnicas Biossensoriais/métodos , COVID-19/tratamento farmacológico , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Animais , Linhagem Celular Tumoral , Chalconas/farmacologia , Cricetulus , Medicamentos de Ervas Chinesas/análise , Efedrina/farmacologia , Células HEK293 , Humanos , Imunidade/efeitos dos fármacos , Inflamação/metabolismo , Pneumopatias/metabolismo , Músculo Liso/efeitos dos fármacos , Receptores Acoplados a Proteínas G/metabolismo , Respiração/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
4.
J Sep Sci ; 44(19): 3530-3539, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34342132

RESUMO

A preparative supercritical fluid chromatography method for the separation of Piper kadsura obtained five phenylamide compounds, which had the same structural skeleton, but changed in the number and position of methoxyl substituents. To improve the separation selectivity of these structural analogues, silica, phenyl, and chiral stationary phases were screened. Only through the combination of Chiral C and phenyl columns could the separation of the five phenylamides be solved. The two-step strategy using preparative supercritical fluid chromatography presented good orthogonality that ensured the purity of the phenylamides. Then, an ultra-high-performance supercritical fluid chromatography hyphened tandem mass spectrometry method was developed, and the fragmentation pattern of phenylamides was summarized. It mainly cleaved in the amide bond to produce the fragment ion, which could help to judge the substituent positions. Twenty-eight possible molecular weights of hydroxyl and methoxyl substituted phenylamides were calculated and screened. Nine compounds were extracted in three [M + H]+ ions at m/z 284.13, 314.13, and 344.13, including five purified compounds and the other four positional or trans-cis phenylamide isomers in low content. The methods developed in this research were useful in the separation and characterization of phenylamide analogues.

5.
Front Chem ; 9: 703176, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34458235

RESUMO

Reversible protein glycosylation and phosphorylation tightly modulate important cellular processes and are closely involved in pathological processes in a crosstalk dependent manner. Because of their significance and low abundances of glyco- and phosphopeptides, several strategies have been developed to simultaneously enrich and co-elute glyco- and phosphopeptides. However, the co-existence of deglycosylated peptides and phosphopeptides aggravates the mass spectrometry analysis. Herein we developed a novel strategy to analyze glyco- and phosphopeptides based on simultaneous enrichment with TiO2, on-line deglycosylation and collection of deglycosylated peptides, and subsequent elution of phosphopeptides. To optimize on-line deglycosylation conditions, the solution pH, buffer types and concentrations, and deglycosylation time were investigated. The application of this novel strategy to 100 µg mouse brain resulted in 355 glycopeptides and 1,975 phosphopeptides, which were 2.5 and 1.4 folds of those enriched with the reported method. This study will expand the application of TiO2 and may shed light on simultaneously monitoring protein multiple post-translational modifications.

6.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360755

RESUMO

Increasing attention is being focused on the use of polypeptide-based N-methyl-d-aspartate (NMDA) receptor antagonists for the treatment of nervous system disorders. In our study on Achyranthes bidentata Blume, we identified an NMDA receptor subtype 2B (NR2B) antagonist that exerts distinct neuroprotective actions. This antagonist is a 33 amino acid peptide, named bidentatide, which contains three disulfide bridges that form a cysteine knot motif. We determined the neuroactive potential of bidentatide by evaluating its in vitro effects against NMDA-mediated excitotoxicity. The results showed that pretreating primary cultured hippocampal neurons with bidentatide prevented NMDA-induced cell death and apoptosis via multiple mechanisms that involved intracellular Ca2+ inhibition, NMDA current inhibition, and apoptosis-related protein expression regulation. These mechanisms were all dependent on bidentatide-induced inhibitory regulation of NR2B-containing NMDA receptors; thus, bidentatide may contribute to the development of neuroprotective agents that would likely possess the high selectivity and safety profiles inherent in peptide drugs.


Assuntos
Achyranthes/química , Hipocampo/metabolismo , Neurônios/metabolismo , Fármacos Neuroprotetores , Peptídeos , Proteínas de Plantas , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/isolamento & purificação , Fármacos Neuroprotetores/farmacologia , Peptídeos/química , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo
7.
ACS Appl Mater Interfaces ; 13(35): 41555-41562, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34428011

RESUMO

Over-lithiated organosulfides, such as sulfurized polyacrylonitrile (SPAN), are promising candidates of lithium metal anode (LMA) protection since they could form robust solid electrolyte interphases (SEIs), which is the key toward stable lithium metal batteries. So far, the mechanism of over-lithiation and evolution of the electrode surface is poorly understood. Herein, several in situ techniques were employed to study the over-lithiation process in SPAN, including in situ Raman spectroscopy to reveal the chemical transformation and in situ electrochemical atomic force microscopy (EC-AFM) to visualize interfacial evolution. The results undoubtedly prove the breaking of the C-S bond and formation of the C-Li bond during the over-lithiation process. The nucleophilic C-Li could further trigger the decomposition of the electrolyte to form an inorganic-organic hybrid SEI on the surface of SPAN, which allows uniform Li deposition and significantly improves the cycle stability of LMAs, as supported by the in situ EC-AFM characterization as well as a series of full cell tests. New insights into the over-lithiation mechanism of SPAN should facilitate the design of organosulfides to construct stable lithium metal anodes.

8.
J Sep Sci ; 44(18): 3441-3449, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34291571

RESUMO

Plant-derived alkaloids are bioactive natural ingredients, but their contents are relatively low in plants. Therefore, the efficient enrichment of alkaloids is a prerequisite for purification and further pharmacological research. In this study, an efficient and simple strategy for enrichment of steroidal alkaloids in Fritillaria was developed for the first time based on the fluorinated reverse-phase stationary phase (FC8HL). Superior selectivity between alkaloids and non-alkaloids was achieved in a non-aqueous system, and a simple solvent system containing low-content additives was applied to elute alkaloids. Key parameters that affected the elution were investigated, including different types of buffer salts and optimized concentrations. The optimized elution system was then applied to selectively enrich alkaloids from five species of Fritillaria. Its practicability was further demonstrated by enrichment of alkaloids from Fritillaria cirrhosa D.Don at a preparative level. This developed method has great potential for other types of hydrophobic alkaloids.

9.
Small ; 17(36): e2102802, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34322996

RESUMO

Ion exchange porous microparticles are widely used for protein separation, but their totally porous structure often leads to slow diffusion rate and long separation time. Here unusual nanofractal microparticles synthesized by a strategy of electrostatic interaction regulated emulsion interfacial polymerization are demonstrated that exhibit excellent capability of rapid protein capture, release, and separation. The growth of nanostructures at nanofractal microparticle surface can be controlled by changing electrostatic repulsion between ion groups from weak to strong. The nanofractal microparticles provide a 3D contact model between ion groups and proteins, enable fast protein diffusion rate at initial capture and release stage, and realize rapid and efficient separation of similarly sized proteins as a proof of concept, superior to porous microparticles. This strategy offers an effective and general way for the synthesis of microparticles towards rapid and efficient separation in various fields of biomedicine, environment, and food.

10.
Se Pu ; 39(6): 588-598, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34227319

RESUMO

Protein glycosylation is among the most important post-translational modifications in living organisms and the research in the field of protein glycosylation continues to garner attention. Currently, the efficient separation and enrichment of glycoproteins and glycopeptides is the primary challenge of glycoproteomics research. The number of glycoproteins is small in complex biological samples. Moreover, the presence of highly-abundant, non-glycosylated, and modified peptides makes the detection of low-abundance glycopeptides more difficult. Therefore, efficient glycopeptide enrichment methods are required to improve the detection of these compounds. The development of highly selective glycopeptide enrichment tools is important to efficiently capture glycoproteins or glycopeptides at the molecular level. Compared with traditional glycopeptide-enriched materials, covalent organic framework materials have the advantages of large specific surface area and rich modification sites, thereby exhibiting great application potential in the field of glycopeptide enrichment. In this study, a novel covalent organic framework material (O-T-D-COFs) was prepared and applied for selective glycopeptide enrichment. We applied the solvothermal method, using 2,5-dimethoxy benzene-1,4-2 formaldehyde and 1,3,5-Tris(4-aminophenyl) benzene, to synthesize imino-based COFs. The Schiff base generated via copolymerization condensation reaction constitutes the framework of the material. Next, the synthesized intermediate material was oxidized to improve the enrichment performance of the material. The functional, specific glycopeptide-binding groups were modified on the COF channels and the structure of the material was characterized using scanning and transmission electron microscope, as well as infrared spectrum and solid-state nuclear magnetic resonance. The enrichment conditions comprised the loading and elution steps, including the optimization of the elution conditions. We could observe the clear profile of 32 glycopeptides derived from human serum immunoglobulin G (IgG) tryptic digests with a significantly improved signal-to-noise (S/N) ratio. We applied a complex sample system to verify the enrichment selectivity of the material when the molar ratios of the IgG and bovine serum albumin (BSA) tryptic digest mixtures reached 1∶50. In addition, we investigated the enrichment performance of the detection limit, enrichment capacity, recovery rate of the material, and the application potential in glycopeptides enrichment using real samples. The material showed a good detection limit (2.5 fmol/µL), an ideal enrichment capacity (120 mg/g), and enrichment recovery (103.5%±6.6% and 101.5%±10.4%). We identified a total of 86 glycopeptides derived from 53 glycoproteins with 94 N-glycosylation sites from only 1 µL human serum. The O-T-D-COFs exhibited a good glycopeptide separation and enrichment potential, indicating that the COF material has promising application potential in glycoproteomics.


Assuntos
Glicopeptídeos , Glicosilação , Estruturas Metalorgânicas , Glicopeptídeos/química , Glicoproteínas/química , Humanos , Interações Hidrofóbicas e Hidrofílicas
11.
Anal Chem ; 93(30): 10444-10452, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34284575

RESUMO

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a serious public health threat. Most vaccines against SARS-CoV-2 target the highly glycosylated spike protein (S). A good knowledge of the glycosylation profile of this protein is key to successful vaccine development. Unlike the 22 confirmed N-glycosylation sites on SARS-CoV-2 S, only a few O-glycosylation sites on this protein have been reported. This difference is mainly ascribed to the extremely low stoichiometry of O-glycosylation. Herein, we designed the biomimetic materials, Trp-Arg (WR) monomer-grafted silica microspheres (designated as WR-SiO2), and these biomimetic materials can enrich N- and O-linked glycopeptides with high selectivity. And WR-SiO2 can resist the nonglycopeptides' interference with the 100 molar fold of BSA during O-linked glycopeptide enrichment. We utilized WR-SiO2 to comprehensively analyze the O-glycosylation profile of recombinant SARS-CoV-2 S. Twenty-seven O-glycosylation sites including 18 unambiguous sites are identified on SARS-CoV-2 S. Our study demonstrates that the biomimetic polymer can offer specific selectivity for O-linked glycopeptides and pave the way for O-glycosylation research in biological fields. The O-glycosylation profile of SARS-CoV-2 S might supplement the comprehensive glycosylation in addition to N-glycosylation of SARS-CoV-2 S.


Assuntos
Materiais Biomiméticos , COVID-19 , Biomimética , Vacinas contra COVID-19 , Glicosilação , Humanos , Pandemias , SARS-CoV-2 , Dióxido de Silício , Glicoproteína da Espícula de Coronavírus/metabolismo
12.
Carbohydr Polym ; 267: 118218, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34119172

RESUMO

Two-dimensional NMR spectroscopies are one of the most frequently used techniques for the structural determination of carbohydrates. However, the data analysis is challenging because of the signal overlap in the 1H homonuclear correlation spectra. We attempted to explore a general strategy for the structural determination of carbohydrates by combined multi-dimensional spectroscopies. The strategy was applied to a human milk oligosaccharide lacto-N-difucohexaose I, that has been previously studied by conventional two-dimensional NMR spectroscopy. Assignment of the intra-residue resonances of the hexasaccharide using the three-dimensional spectrum was straightforward. Consequently, data analysis of the multi-dimensional spectra was significantly simplified, leading to a quicker determination of the intra- and inter-residue connections in the hexasaccharide. Application of the NMR strategy to chondroitin sulfate from bovine cartilage revealed two repeating disaccharide regions of the A and C units of chondroitin sulfate, indicating the high potential of this technique for the structural determination of complex polysaccharides.

13.
J Ethnopharmacol ; 278: 114335, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34139281

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Dopamine receptors are long-standing primary targets in the treatment of mental diseases and there is growing evidence that suggests relationships between obesity and the dopamine system, especially dopamine D1 and D2 receptors. Leaves of Nelumbo nucifera Gaertn. (lotus leaves) have been medically used for helping long-term maintenance of weight loss. Whether and how components of lotus leaves function through the dopamine receptors remains unclear. AIM OF THE STUDY: This work aimed to discover dopamine receptor-active alkaloids isolated from the lotus leaves, to evaluate their potencies and to analyze their structure activity relationship. MATERIALS AND METHODS: Dried lotus leaves were prepared and total extract was divided into alkaloids and flavones. Eight alkaloids were separated and characterized by a combination of high-performance liquid chromatography, quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance, and assayed by a fluorometric imaging plate reader platform. Human embryonic kidney 239 cell lines expressing dopamine D1, D2 and serotonin 2A (5-HT2A) receptors, respectively, were cultured and used in the assay. RESULTS: Alkaloids in the lotus leaves were the bioactive phytochemicals and inhibited dopamine from accessing the D1 and D2 receptors. All eight compounds functioned as D1-receptor antagonists and except N-nornuciferine, seven alkaloids functioned as D2-receptor antagonists. (S)-coclaurine and (R)-coclaurine are optical isomers and antagonized both D1 and D2 with equivalent potencies, suggesting that the optical rotation of the methylene linker in the monobenzyl isoquinoline backbone did not influence their activity. Among the eight alkaloids, O-nornuciferine was the potent antagonist to both receptors (the lowest IC50 values, D1: 2.09 ± 0.65 µM and D2: 1.14 ± 0.10 µM) while N-nornuciferine was found to be the least potent as it moderately antagonized D1 and was inactive on D2. O-nornuciferine was also a 5-HT2A antagonist (IC50~20 µM) while N-nornuciferine had no activity. These hinted the importance of a methyl group attached to the nitrogen atom in the aporphine backbone. Armepavine showed a nearly 10-fold selectivity to D2. CONCLUSIONS: In this work, eight alkaloids were isolated from the leaves of Nelumbo nucifera Gaertn. and assayed on the D1 and D2 receptors. They were D1/D2 antagonists with IC50 values in the mid- to low-micromolar range and O-nornuciferine was the most potent alkaloid among the eight. This family of alkaloids was biochemically evaluated on the dopamine receptors by the same platform for the first time.

14.
J Clin Transl Hepatol ; 9(2): 143-148, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-34007795

RESUMO

Background and Aims: Drug-resistant DNA mutations of the hepatitis B virus (HBV) affect treatment response in chronic hepatitis B patients. We have established a new, sensitive, specific, accurate and convenient real-time PCR method to detect HBV mutations quantitatively. Methods: Blood samples were collected from patients showing viral breakthrough, primary nonresponse, or poor response during treatment, and mutations were detected via direct sequencing to assess our method. A plasmid containing the M204V mutation was synthesized and standard curves plotted. Results: The determination coefficient for linear correlation between Ct and log plasmid copy numbers was 0.996, where Ct value was -3.723log (DNA concentration) +48.647. Coefficients of variation indicated good reproducibility. Correctness was within tolerable bias. Limit of detection was 103 copies/mL. Specificity, accuracy, positive predictive value and negative predictive value were 92.86%, 100%, 96.88%, 100% and 94.74%, respectively. Conclusions: These results show that our method can be used to detect HBV M204V mutations with the advantages of sensitivity, specificity and efficiency, providing a new choice for monitoring drug resistance.

15.
Anal Chem ; 93(20): 7473-7480, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-33973768

RESUMO

Bottom-up proteomics has been increasingly applied in clinical research to study the disease pathophysiology and to discover disease biomarkers. However, glycoproteomic analysis always requires tedious experimental steps for intact glycopeptide enrichment, which has been the technique bottleneck for large-scale analysis of clinical samples. Herein, we developed an automated glycopeptide enrichment method for the analysis of serum site-specific N-glycoproteome. This automated method allowed for processing one sample within 20 min. It showed higher enrichment specificity, more intact glycopeptide identifications, and better quantitative reproducibility than the traditional manual method using microtip enrichment devices. We further applied this method to investigate the serum site-specific N-glycosylation changes between four patients with pancreatic cancer and seven healthy controls. The principal component analysis of intact N-glycopeptides showed good clustering across cancer and normal groups. Furthermore, we found that the site-specific glycoforms, monofucosylated and nonsialylated oligosaccharides, on IgG1 site 180 expressed a significant decrease in pancreatic cancer patients compared to healthy controls. Together, the automated method is a powerful tool for site-specific N-glycoproteomic analysis of complex biological samples, and it has great potential for clinical utilities.


Assuntos
Glicopeptídeos , Proteoma , Glicosilação , Humanos , Proteômica , Reprodutibilidade dos Testes
16.
Chin J Nat Med ; 19(4): 305-320, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33875170

RESUMO

Qing-Fei-Pai-Du decoction (QFPDD) is a Chinese medicine compound formula recommended for combating corona virus disease 2019 (COVID-19) by National Health Commission of the People's Republic of China. The latest clinical study showed that early treatment with QFPDD was associated with favorable outcomes for patient recovery, viral shedding, hospital stay, and course of the disease. However, the effective constituents of QFPDD remain unclear. In this study, an UHPLC-Q-Orbitrap HRMS based method was developed to identify the chemical constituents in QFPDD and the absorbed prototypes as well as the metabolites in mice serum and tissues following oral administration of QFPDD. A total of 405 chemicals, including 40 kinds of alkaloids, 162 kinds of flavonoids, 44 kinds of organic acids, 71 kinds of triterpene saponins and 88 kinds of other compounds in the water extract of QFPDD were tentatively identified via comparison with the retention times and MS/MS spectra of the standards or refereed by literature. With the help of the standards and in vitro metabolites, 195 chemical components (including 104 prototypes and 91 metabolites) were identified in mice serum after oral administration of QFPDD. In addition, 165, 177, 112, 120, 44, 53 constituents were identified in the lung, liver, heart, kidney, brain, and spleen of QFPDD-treated mice, respectively. These findings provided key information and guidance for further investigation on the pharmacologically active substances and clinical applications of QFPDD.


Assuntos
Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacocinética , Administração Oral , Alcaloides/análise , Animais , COVID-19 , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Camundongos , SARS-CoV-2 , Saponinas/análise , Triterpenos/análise
17.
Artigo em Inglês | MEDLINE | ID: mdl-33906077

RESUMO

In this paper, an effective strategy of using acetonitrile-methanol-water as mobile phase was developed to achieve acceptable peak shape of steviol glycosides in reversed-phase liquid chromatography (RPLC). The change of elution profiles of rebaudioside A (RA) was systematically investigated. Two classical distributions, namely, tailing and fronting peaks resulting from injections of RA solution in range of 0.5-5 mg were both observed in a ternary eluent of acetonitrile-methanol-water (21:43:36, v/v). Next, a three-phase diagram of tailing factor (Tf) was illustrated, showing high dependence of elution profile of RA on the ternary composition. The peak shape of RA can be adjusted mainly based on the additive effect, that is, acetonitrile is more strongly adsorbed to the stationary phase than RA in the pure weak solvent (H2O). Therefore, with the increase of acetonitrile concentration in the ternary eluent, the RA band profiles went from being tailing to fronting shapes. At the same time, due to the large RA-RA interactions, there was anti-Langmuir adsorption isotherm in acetonitrile-water mobile phase, which is the reason for the fronting peaks of RA. It could be concluded that the way of using the ternary eluent of acetonitrile-methanol-water does control and tune the peak shape of steviol glycosides in RPLC separation.

18.
J Sep Sci ; 44(12): 2382-2390, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33835699

RESUMO

Bioactivity-guided chromatographic methods are of great significance for the isolation of the active compounds in complex samples. In this study, four anti-fungal compounds were located by activity screening and successfully isolated from a microbial fermentation sample by preparative high-performance liquid chromatography. Separation performance of columns including C18, positively charged C18, negatively charged C18 and C8 were firstly investigated. And it showed a better capacity of mixed-mode stationary phases for retention and separation. Therefore, the positively charged C18 column was used to separate the sample into several fractions, among which the active one was identified by the antifungal test. And then the active fraction was enriched and separated again by successively using the negatively charged C18 and C8 columns to obtain four compounds, which were identified as polyoxins A, K, F and H. With activity verification, four polyoxins were found to have good inhibitory effects against the three fungal plant diseases including rice sheath blight, tomato grey mould disease, and apple spot leaf disease.

19.
Carbohydr Polym ; 259: 117734, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33673995

RESUMO

Oligosaccharides are one of the most important components in mammalian milk. Milk oligosaccharides can promote colonization of gut microbiota and protect newborns from infections. The diversity and structures of MOs differ among mammalian species. MOs in human and farm animals have been well-documented. However, the knowledge on MOs in rat and mouse have been very limited even though they are the most-widely used models for studies of human physiology and disease. Herein, we use a high-sensitivity online solid-phase extraction and HILIC coupled with electrospray tandem mass spectrometry to analyze the acidic MOs in rat and mouse. Among the fifteen MOs identified, twelve were reported for the first time in rat and mouse together with two novel sulphated oligosaccharides. The complete list of acidic oligosaccharides present in rat and mouse milk is the baseline information of these animals and should contribute to biological/biomedical studies using rats and mice as models.


Assuntos
Leite/metabolismo , Oligossacarídeos/análise , Espectrometria de Massas por Ionização por Electrospray , Animais , Cromatografia Líquida de Alta Pressão , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Oligossacarídeos/isolamento & purificação , Ratos , Extração em Fase Sólida
20.
Talanta ; 226: 122112, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676668

RESUMO

Glycosylation is one of the most important post-translational modifications of proteins, and plays an important role in the structure and function of proteins. However, due to the diversity of glycopeptide forms and their low abundance, it is extraordinarily challenging to capture and separate glycopeptides with high selectivity from complex biological samples with mass spectrometric analysis. Here, we synthesized a new type of hydrophilic composite based on electrostatic interactions, which has been proven to be effective in immobilizing cationic cellulose on graphene oxide-dopamine carriers (expressed as GO-DA-JR), for highly specific enrichment of N-glycopeptides. The introduction of cationic cellulose provides not only a perfect surface charge for the composite but also a greater ability to enrich glycosylated peptides. Thirty-two glycopeptides from human serum immunoglobulin G (IgG) tryptic digests were observed with a greatly improved signal-to-noise ratio (S/N) and also presented high performance in anti-interfering enrichment of glycopeptides from complex samples containing 100-fold bovine serum albumin tryptic digests. In addition, GO-DA-JR has higher sensitivity (1 fmol/µL IgG) and better enrichment capacity (up to 150 mg/g). Moreover, the results of glycopeptide enrichment and glycosylation analysis from human serum also show egood enrichment selectivity from real biological samples. This work exhibits high selectivity, high sensitivity, good stability and operability, indicating its potential for applications of glycopeptides enrichment in post-translational modification proteomics.


Assuntos
Glicopeptídeos , Grafite , Celulose , Dopamina , Humanos , Interações Hidrofóbicas e Hidrofílicas
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