Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Nat Methods ; 20(1): 123-130, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36522503

RESUMO

Cryo-electron microscopy (cryo-EM) visualizes the atomic structure of macromolecules that are embedded in vitrified thin ice at their close-to-native state. However, the homogeneity of ice thickness, a key factor to ensure high image quality, is poorly controlled during specimen preparation and has become one of the main challenges for high-resolution cryo-EM. Here we found that the uniformity of thin ice relies on the surface flatness of the supporting film, and developed a method to use ultraflat graphene (UFG) as the support for cryo-EM specimen preparation to achieve better control of vitreous ice thickness. We show that the uniform thin ice on UFG improves the image quality of vitrified specimens. Using such a method we successfully determined the three-dimensional structures of hemoglobin (64 kDa), α-fetoprotein (67 kDa) with no symmetry, and streptavidin (52 kDa) at a resolution of 3.5 Å, 2.6 Å and 2.2 Å, respectively. Furthermore, our results demonstrate the potential of UFG for the fields of cryo-electron tomography and structure-based drug discovery.


Assuntos
Grafite , Microscopia Crioeletrônica/métodos , Grafite/química , Substâncias Macromoleculares , Tomografia com Microscopia Eletrônica
2.
Sensors (Basel) ; 24(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38793998

RESUMO

Hydrogen is an ideal energy carrier manufactured mainly by the natural gas steam reforming hydrogen production process. The concentrations of CH4, CO, CO2, and H2 in this process are key variables related to product quality, which thus need to be controlled accurately in real-time. However, conventional measurement methods for these concentrations suffer from significant delays or huge acquisition and upkeep costs. Virtual sensors effectively compensate for these shortcomings. Unfortunately, previously developed virtual sensors have not fully considered the complex characteristics of the hydrogen production process. Therefore, a virtual sensor model, called "moving window-based dynamic variational Bayesian principal component analysis (MW-DVBPCA)" is developed for key gas concentration estimation. The MW-DVBPCA considers complicated characteristics of the hydrogen production process, involving dynamics, time variations, and transportation delays. Specifically, the dynamics are modeled by the finite impulse response paradigm, the transportation delays are automatically determined using the differential evolution algorithm, and the time variations are captured by the moving window method. Moreover, a comparative study of data-driven virtual sensors is carried out, which is sporadically discussed in the literature. Meanwhile, the performance of the developed MW-DVBPCA is verified by the real-life natural gas steam reforming hydrogen production process.

3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(3): 312-316, 2024 Mar 10.
Artigo em Zh | MEDLINE | ID: mdl-38448020

RESUMO

OBJECTIVE: To analyze the clinical phenotype and genetic characteristics of a Chinese pedigree affected with Hereditary antithrombin deficiency. METHODS: A pedigree diagnosed at the the Second Affiliated Hospital of Wenzhou Medical University, Yuying Children's Hospital in June, 2020 was selected as the study subject. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and thrombin time (TT) of the probands and their pedigree members were determined using a STA-R automatic coagulation analyzer. Antithrombin activity (AT: A) and antithrombin antigen (AT: Ag) in plasma were determined with chromogenic substrate and immunonephelometry assays. All exons and flanking sequences of the anticoagulant protein gene SERPINC1 were amplified by PCR and subjected to Sanger sequencing. Candidate variants were verified with bioinformatic tools (PolyPhen-2, SIFT, Mutation Taster and PYMOL) to explore their effect on the function and structural conformation of the protein. RESULTS: The probands (II-2, II-10), their brother (II-5) and sons (III-1, III-8) had shown normal PT, APTT, FIB, and TT, but significantly decreased AT: A and AT: Ag, with their levels being 34%, 57%, 56%, 48%, 53% and 13.51 mg/dL, 13.44 mg/dL, 18.39 mg/dL, 17.36 mg/dL, 17.71 mg/dL, respectively. The remaining pedigree members had normal values. Sanger sequencing revealed that the probands and all affected pedigree members had harbored a heterozygous c.851T>C (p.Met284Thr) missense variant in exon 5 of the SERPINC1 gene. Bioinformatic analysis and simulation suggested that the variant has resulted in alteration of hydrogen bonds at the c.851 position, which may affect the structure of the protein. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic (PS1+PM1+PM5+PP1+PP4). CONCLUSION: The probands and other affected members were all diagnosed with type I hereditary AT deficiency, for which the c.851T>C (p.Met284Thr) variant of the SERPINC1 gene may be accountable.


Assuntos
Deficiência de Antitrombina III , Masculino , Criança , Humanos , Deficiência de Antitrombina III/genética , Linhagem , Éxons , Fibrinogênio , Anticoagulantes , Antitrombinas , China , Antitrombina III/genética
4.
Anal Chem ; 95(24): 9323-9329, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-37272674

RESUMO

The ligand-receptor signaling occurring on the cell surface governs cell growth, proliferation, and survival via rapidly triggering a cascade of events. Here, we for the first time report an in situ perturbation-free and rapid surface proteomic profiling at a temporal resolution of ten seconds. By this innovation, about 1022 cell surface-associated proteins were reproducibly identified and quantified. It is noteworthy that, upon a model ligand insulin stimulus, a few rapid-responding proteins at 10 s to 2 min were identified, e.g., CNNM3. Moreover, temporal response patterns were established for the members of GLUT4 storage vesicles (GSVs; responsible for glucose transportation) and confirmed with five known GSV proteins. This pattern was then exploited to uncover seven new regulatory proteins (LDLR, HFE, ECE1, MRC2, CORO1C, CPD, and BST2). Collectively, we showed a powerful surface proteomic tool to decipher rapid signaling of cell-surface proteins and to uncover new subunits involved in rapidly trafficking vesicles.


Assuntos
Insulina , Proteômica , Ligantes , Membrana Celular/metabolismo , Insulina/metabolismo , Transdução de Sinais , Transporte Proteico
5.
Anal Chem ; 94(10): 4155-4164, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35239328

RESUMO

Protein tyrosine phosphorylation (pTyr) plays a prominent role in signal transduction and regulation in all eukaryotic cells. In conventional immunoaffinity purification (IP) methods, phosphotyrosine peptides are isolated from the digest of cellular protein extracts with a phosphotyrosine-specific antibody and are identified by tandem mass spectrometry. However, low sensitivity, poor reproducibility, and high cost are universal concerns for IP approaches. In this study, we presented an antibody-free approach to identify phosphotyrosine peptides by using protein tyrosine phosphatase (PTP). It was found that most of the PTPs including PTP1B, TCPTP, and SHP1 can efficiently and selectively dephosphorylate phosphotyrosine peptides. We then designed a workflow by combining two Ti4+-IMAC-based phosphopeptide enrichment steps with PTP-catalyzed dephosphorylation for tyrosine phosphoproteomics analysis. This workflow was first validated by selective detection of phosphotyrosine peptides from semicomplex samples and then applied to analyze the tyrosine phosphoproteome of Jurkat T cells. Around 1000 putative former phosphotyrosine peptides were identified from less than 500 µg of cell lysate. The tyrosine phosphosites on the majority of these peptides could be unambiguously determined for over 70% of them possessing only one tyrosine residue. It was also found that the tyrosine sites identified by this method were highly complementary to those identified by the SH2 superbinder-based method. Therefore, the combination of Ti4+-IMAC enrichment with PTP dephosphorylation provides an alternative and cost-effective approach for tyrosine phosphoproteomics analysis.


Assuntos
Proteômica , Tirosina , Humanos , Peptídeos/química , Fosforilação , Fosfotirosina/química , Proteínas Tirosina Fosfatases , Proteoma/análise , Proteômica/métodos , Reprodutibilidade dos Testes , Tirosina/química
6.
J Sep Sci ; 45(7): 1336-1344, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35108751

RESUMO

Selective separation and enrichment of phosphoproteins are essential for understanding their important functions in almost all cellular processes. Here, taking advantage of the feature that cadmium ion (Cd2+ ) has an overwhelming preference for phosphates, we developed a robust and simple Cd2+ co-precipitation strategy for the selective isolation of intact phosphoproteins. After evaluating the feasibility of Cd2+ in phosphoprotein precipitation, we compared the washing protocols for the removal of non-specific binding proteins and then used the best-performing protocol for the isolation of phosphoproteins from different complex samples. It was found that phosphoproteins can be specifically enriched from artificial protein mixtures containing α-casein, ß-casein, and bovine serum albumin or plasma, in which bovine serum albumin or plasma were served as interferences with very high molar ratios. Applying this method to enrich phosphoproteins from complex cell lysates, a high specificity was confirmed by western blotting analysis with a phosphoprotein-specific kit. Finally, we successfully applied this method to the purification of caseins from drinking milk, highlighting its potential application in the studies where purified phosphoproteins were required. In a word, this Cd2+ co-precipitation method enables universal and effective capture, enrichment, and detection of intact phosphoproteins, making it a powerful tool for the comprehensive analysis of the phosphoproteome.


Assuntos
Cádmio , Fosfoproteínas , Caseínas/análise , Fosfatos , Soroalbumina Bovina/análise
7.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 39(6): 587-591, 2022 Jun 10.
Artigo em Zh | MEDLINE | ID: mdl-35773760

RESUMO

OBJECTIVE: To analyze the phenotype and genotype of two Chinese family with inherited dysfibrinogenemia and the molecular pathogenic mechanism. METHODS: In the probands and their family members, coagulation routine, fibrinogen activity (Fg: A) and fibrinogen antigen (Fg: Ag) were detected. To find the mutation and exclude single nucleotide polymorphisms, all the exons and exons-intron boundaries of fibrinogen genes (FGA, FGB and FGG) were amplified by Ploymerase Chain Reaction (PCR), then sequenced. Bioinformatics prediction softwares were used to predict and score the change of function caused by the variant. PyMol were used to analyze the structure of protein caused by the variant. Clustal X software was used to analyze the conservation of the mutant amino acids. RESULTS: The thrombin time (TT) of the two was slightly prolonged and could not be corrected by protamine sulfate, and the fibrinogen activity was significantly reduced (1.25 g/L and 1.17 g/L), but the fibrinogen antigen content was normal, respectively (3.50 g /L and 3.81 g/L). Genetic analysis showed that both probands were heterozygous missense variants (FGB exon 7 c.1115T>A (p.Val372Glu)), both of which originated from the paternal line. The prediction results of the four bioinformatics softwares indicate that this variant could be disease causing. Clustal X software showed that Val372 is highly conserved among homologous species. Based on the guidelines of the American College of Medical Genetics and Genomics, c.1115T>A was predicted to be likely pathgenic (PM2+PP1+PP2+PP3+PP4). PyMol showed that the secondary structure and three-dimensional structure of fibrinogen protein were changed by p.Val372Glu variant. CONCLUSION: Inherited dysfibrinogenemia of the probands maybe caused by variant of FGB c.1115 T>A (p.Val372Glu), and the variant was firstly reported.


Assuntos
Afibrinogenemia , Fibrinogênio , Afibrinogenemia/genética , Fibrinogênio/genética , Humanos , Mutação , Linhagem , Fenótipo
8.
Anal Chem ; 93(10): 4542-4551, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33660993

RESUMO

Cell surface is the primary site for sensing extracellular stimuli. The knowledge of the transient changes on the surfaceome upon a perturbation is very important as the initial changed proteins could be driving molecules for some phenotype. In this study, we report a fast cell surface labeling strategy based on peroxidase-mediated oxidative tyrosine coupling strategy, enabling efficient and selective cell surface labeling within seconds. With a labeling time of 1 min, 2684 proteins, including 1370 (51%) cell surface-annotated proteins (cell surface/plasma membrane/extracellular), 732 transmembrane proteins, and 81 cluster of differentiation antigens, were identified from HeLa cells. By comparison with the negative control experiment using quantitative proteomics, 500 (68%) out of the 731 significantly enriched proteins (p-value < 0.05, ≥2-fold) in positive experimental samples were cell surface-annotated proteins. Finally, this technology was applied to track the dynamic changes of the surfaceome upon insulin stimulation at two time points (5 min and 2 h) in HepG2 cells. Thirty-two proteins, including INSR, CTNNB1, TFRC, IGF2R, and SORT1, were found to be significantly regulated (p-value < 0.01, ≥1.5-fold) after insulin exposure by different mechanisms. We envision that this technique could be a powerful tool to analyze the transient changes of the surfaceome with a good time resolution and to delineate the temporal and spatial regulation of cellular signaling.


Assuntos
Proteoma , Proteômica , Biotinilação , Membrana Celular/metabolismo , Células HeLa , Humanos , Proteoma/metabolismo
9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(11): 1250-1252, 2020 Nov 10.
Artigo em Zh | MEDLINE | ID: mdl-33179232

RESUMO

OBJECTIVE: To analyze the phenotype and genotype of a patient affected with inherited antithrombin deficiency. METHODS: All exons and exon-intron boundaries of the AT genes were subjected to PCR amplification and Sanger sequencing. The influence of variants on the disease was predicted using bioinformatic software (MutationTaster). RESULTS: The results of all coagulation tests were normal, though the antithrombin activity and antigen content of the proband and his father have decreased significantly (34%, 48% and 12.97 mg/dL, 15.60 mg/dL, respectively). His mother was normal. Genetic analysis revealed that the proband and his father both carried a heterozygous g.2736dupT variant of the AT gene. Bioinformatic analysis suggested that the variant may be pathogenic. CONCLUSION: The proband and his father both had type I hereditary antithrombin deficiency caused by a g.2736dupT variant of the AT gene. The variant was unreported previously.


Assuntos
Deficiência de Antitrombina III , Antitrombina III/genética , Deficiência de Antitrombina III/genética , Análise Mutacional de DNA , Testes Genéticos , Heterozigoto , Humanos , Masculino , Mutação , Linhagem
10.
J Proteome Res ; 18(4): 1870-1879, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30875230

RESUMO

Tyrosine phosphorylation plays a major role in regulating cell signaling pathways governing diverse biological functions such as proliferation and differentiation. Systemically mapping phosphotyrosine (pTyr) sites is the key to understanding molecular mechanisms underlining pTyr-dependent signaling. Although mass spectrometry-based technologies have been widely used for pTyr site profiling and quantification, their applications are often hindered by the poor efficiency in current multistep enrichment procedures for inherently low abundance pTyr peptides, especially under physiological conditions. Taking advantage of the sequence-independent high affinity of SH2 superbinder toward pTyr residues, we have developed a simplified one-step pTyr peptide enrichment method that uses immobilized SH2 superbinder for unbiased and robust enrichment of endogenous pTyr peptides from biological samples. By eliminating the prerequisite global phosphopeptide enrichment step in our previously developed two-step method, we minimized sample loss and improved peptide capture efficiency. Applying this method to Jurkat cells at resting state, where the tyrosine phosphorylation level is low, both the number of identified pTyr peptides and sites are increased by three folds compared to the two-step method. Specifically, we were able to identify 511 nonredundant pTyr peptides, corresponding to 403 high confidence pTyr sites, from Jurkat cells with high level technical reproducibility (Pearson's correlation coefficient as high as 0.94). Further applying this method to two human breast cancer cell lines, BT474 and HCC1954, before and after EGF stimulation, we demonstrated that this approach could be a powerful tool for illustrating pTyr-dependent signaling network controlling cellular behaviors such as drug resistance.


Assuntos
Fosfopeptídeos , Fosfotirosina , Proteômica/métodos , Domínios de Homologia de src , Linhagem Celular Tumoral , Humanos , Células Jurkat , Fosfopeptídeos/análise , Fosfopeptídeos/química , Fosfopeptídeos/metabolismo , Fosforilação , Fosfotirosina/análise , Fosfotirosina/química , Fosfotirosina/metabolismo , Proteoma/análise , Proteoma/química , Proteoma/metabolismo , Transdução de Sinais
11.
J Proteome Res ; 17(1): 243-251, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29083189

RESUMO

In this study, we present a method to specifically capture phosphotyrosine (pTyr) peptides from minute amount of sample for the sensitive analysis of protein tyrosine phosphorylation. We immobilized SH2 superbinder on a monolithic capillary column to construct a microreactor to enrich pTyr peptides. It was found that the synthetic pTyr peptide could be specifically enriched by the microreactor from the peptide mixture prepared by spiking of the synthetic pTyr peptide into the tryptic digests of α-casein and ß-casein with molar ratios of 1:1000:1000. The microreactor was further applied to enrich pTyr peptides from pervanadate-treated HeLa cell digests for phosphoproteomics analysis, which resulted in the identification of 796 unique pTyr sites. In contrast, the conventional SH2 superbinder-based method identified 41 pTyr sites for the same sample, only 5.2% of the number achieved by the microreactor. Finally, this microreactor was also applied to analyze the pTyr in Shc1 complex, an immunopurified protein complex, which resulted in the identification of 15 pTyr sites. Together, this technique is best fitted to analyze the pTyr in minute amount of sample and will have broad application in fields where only a limited amount of sample is available.


Assuntos
Proteômica/instrumentação , Tirosina/metabolismo , Desenho de Equipamento , Células HeLa , Humanos , Fosforilação , Fosfotirosina/análise , Proteômica/métodos
12.
Anal Chem ; 90(21): 12714-12722, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30350625

RESUMO

Human serum is a complex body fluid that contains various N-linked and O-linked glycoproteins. Compared with N-linked glycoproteins, the serum O-linked glycoproteins are not well-studied due to their high heterogeneity and their low abundance. Herein, we presented a novel chemoenzymatic method to analyze core-1 type of O-GalNAcylation in human serum. In this approach, the tryptic digest of serum was first subjected to PNGase F treatment to release the N-glycan and was then treated with strong acid to release sialic acid residues from mucin-type O-glycans. In this way, the internal Gal/GalNAc residues were exposed and were oxidized by the galactose oxidase to carry the aldehyde groups. The oxidized O-GalNAcylated peptides were then captured by hydrazide beads and eluted with methoxylamine for LC-MS/MS analysis. The de-N-deglycosylation decreased the abundance of N-glycopeptides, the desialylation simplified the O-glycans and the enzymatic oxidization conferred the enrichment specificity. We have demonstrated that this method was fitted to analyze O-GalNAcylated peptides with high confidence. This method was applied to analyze human serum, which resulted in the identification of 59 O-GalNAc modified peptide sequences corresponding to 38 glycoproteins from 50 µL of serum. This method is expected to have broad applications in the analysis of O-glycoproteome.


Assuntos
Proteínas Sanguíneas/análise , Glicoproteínas/análise , Proteômica/métodos , Proteínas Sanguíneas/química , Cromatografia Líquida , Galactose Oxidase/química , Glicopeptídeos/análise , Glicopeptídeos/química , Glicoproteínas/química , Glicosilação , Humanos , Hidrólise , Células Jurkat , Oxirredução , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase/química , Proteólise , Espectrometria de Massas em Tandem , Tripsina/química
13.
Anal Chem ; 90(12): 7617-7625, 2018 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-29799184

RESUMO

Selective enrichment and sensitive detection of phosphopeptides are of great significance in many bioapplications. In this work, dendritic mesoporous silica nanoparticles modified with polydopamine and chelated Ti4+ (denoted DMSNs@PDA-Ti4+) were developed to improve the enrichment selectivity of phosphopeptides. The unique central-radial pore structures endowed DMSNs@PDA-Ti4+ with a high surface area (362 m2 g-1), a large pore volume (1.37 cm3 g-1), and a high amount of chelated Ti4+ (75 µg mg-1). Compared with conventional mesoporous silica-based materials with the same functionalization (denoted mSiO2@PDA-Ti4+) and commercial TiO2, DMSNs@PDA-Ti4+ showed better selectivity and a lower detection limit (0.2 fmol/µL). Moreover, 2422 unique phosphopeptides were identified from HeLa cell extracts with a high specificity (>95%) enabled by DMSNs@PDA-Ti4+, better than those in previous reports.


Assuntos
Nanopartículas/química , Neoplasias/química , Neoplasias/patologia , Fosfopeptídeos/análise , Dióxido de Silício/química , Titânio/química , Células HeLa , Humanos , Indóis/química , Estrutura Molecular , Tamanho da Partícula , Polímeros/química , Porosidade , Propriedades de Superfície
14.
Anal Chem ; 90(10): 6214-6221, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29660285

RESUMO

In this study, we presented an enrichment-free approach for the sensitive analysis of protein phosphorylation in minute amounts of samples, such as purified protein complexes. This method takes advantage of the high sensitivity of parallel reaction monitoring (PRM). Specifically, low confident phosphopeptides identified from the data-dependent acquisition (DDA) data set were used to build a pseudotargeted list for PRM analysis to allow the identification of additional phosphopeptides with high confidence. The development of this targeted approach is very easy as the same sample and the same LC-system were used for the discovery and the targeted analysis phases. No sample fractionation or enrichment was required for the discovery phase which allowed this method to analyze minute amount of sample. We applied this pseudotargeted MS method to quantitatively examine phosphopeptides in affinity purified endogenous Shc1 protein complexes at four temporal stages of EGF signaling and identified 82 phospho-sites. To our knowledge, this is the highest number of phospho-sites identified from the protein complexes. This pseudotargeted MS method is highly sensitive in the identification of low abundance phosphopeptides and could be a powerful tool to study phosphorylation-regulated assembly of protein complex.


Assuntos
Fosfopeptídeos/análise , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/análise , Cromatografia Líquida , Células HeLa , Humanos , Espectrometria de Massas , Fosfopeptídeos/metabolismo , Fosforilação , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src/metabolismo , Células Tumorais Cultivadas
15.
Anal Chem ; 89(8): 4655-4662, 2017 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-28316239

RESUMO

Hierarchically porous materials have become a key feature of biological materials and have been widely applied for adsorption or catalysis. Herein, we presented a new approach to directly prepare a phosphate-functionalized hierarchically porous hybrid monolith (HPHM), which simultaneously contained mesopores and macropores. The design was based on the copolymerization of polyhedral oligomeric vinylsilsesquioxanes (vinylPOSS) and vinylphosphonic acid (VPA) by adding degradable polycaprolactone (PCL) additive. The phosphate groups could be directly introduced into the hybrid monoliths. This approach was simple and time-saving, and overcame the defect of a rigorous, complex process for preparing traditional Ti4+-immobilized metal ion affinity chromatography (IMAC) materials. The specific surface area of an optimal hybrid monolith could reach 502 m2/g obtained by nitrogen adsorption/desorption measurements, which originated from the degradation of PCL. Meanwhile, the characterization of scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) also suggested that the macropores existed in the hybrid monoliths. The size of macropores could be controlled by the content of PCL in the polymerization mixture. The prepared Ti4+-IMAC HPHMs exhibited high adsorption capacity (63.6 mg/g for pyridocal 5'-phosphatemonohydrate), and excellent enrichment specificity (tryptic digest of ß-casein/BSA at a molar ratio of 1:1000) and sensitivity (tryptic digest of 5 fmol of ß-casein). Moreover, the Ti4+-IMAC HPHMs provided effective enrichment ability of low-abundance phosphopeptides from human serum and HeLa cell digests.


Assuntos
Cromatografia de Afinidade/métodos , Fosfopeptídeos/análise , Titânio/química , Adsorção , Animais , Caseínas/metabolismo , Bovinos , Células HeLa , Humanos , Organofosfonatos/química , Compostos de Organossilício/química , Fosfopeptídeos/sangue , Fosfopeptídeos/isolamento & purificação , Poliésteres/química , Porosidade , Soroalbumina Bovina/metabolismo , Compostos de Vinila/química
16.
Anal Chem ; 89(17): 9307-9314, 2017 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-28796482

RESUMO

Albeit much less abundant than Ser/Thr phosphorylation (pSer/pThr), Tyr phosphorylation (pTyr) is considered as a hallmark in cellular signal transduction. However, its analysis at the proteome level remains challenging. The conventional immunopurification (IP) approach using antibodies specific to pTyr sites is known to have low sensitivity, poor reproducibility and high cost. Our recent study indicated that SH2 domain-derived pTyr-superbinder is a good replacement of pTyr antibody for the specific enrichment of pTyr peptides for phosphoproteomics analysis. In this study, we presented an efficient SH2 superbinder based workflow for the sensitive analysis of tyrosine phosphoproteome. This new method can identify 41% more pTyr peptides than the previous method. Its excellent performance was demonstrated by the analysis of a variety of different samples. For the highly tyrosine phosphorylated sample, for example, pervanadate-treated Jurkat T cells, it identified over 1800 high confident pTyr sites from only 2 mg of proteins. For the unstimulated Jurkat cells, where the pTyr events rarely occurred, it identified 343 high confident pTyr sites from 5 mg of proteins, which was 31% more than that obtained by the antibody-based method. For the heterogeneous sample of tissue, it identified 197 high confident pTyr sites from 5 mg protein digest of mouse skeletal muscle. In general, it is a sensitive, robust and cost-effective approach and would have wide applications in the study of the regulatory role of tyrosine phosphorylation in diverse physiological and pathological processes.


Assuntos
Proteoma/análise , Tirosina/química , Tirosina/metabolismo , Sequência de Aminoácidos , Humanos , Células Jurkat , Espectrometria de Massas/métodos , Peptídeos/química , Peptídeos/metabolismo , Fosforilação , Proteômica/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Anal Chem ; 87(22): 11353-60, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26470016

RESUMO

A problem for "shot-gun" proteomics is that the peptides generated in the proteolysis step overwhelm the analytical capacity of current LC-MS/MS systems. A straightforward approach to overcome this problem is to reduce the sample complexity by isolating the representative peptides of each protein. In this study, we presented a facile solid-phase capture-release approach to selectively enrich the peptides with N-terminal serine/threonine from protein digests. This method exploited the highly efficient reaction between an aldehyde group and a hydrazine group. The excellent performance of this approach was validated using synthetic peptides as well as complex protein digests. It was found that high enrichment specificity could be obtained and the identifications for complex samples with and without enrichment were highly complementary. Besides, the enrichment of peptides with serine/threonine adjacent to different protease cleavage sites demonstrated that our method was able to enrich peptides from protein digests in a sequence specific way. As a result, this new approach provides a simple way to reduce sample complexity and facilitates the identification of low-abundance proteins.


Assuntos
Peptídeos/química , Peptídeos/isolamento & purificação , Proteômica/métodos , Serina/química , Treonina/química , Cromatografia Líquida de Alta Pressão , Humanos , Peptídeos/metabolismo , Serina/metabolismo , Espectrometria de Massas em Tandem , Treonina/metabolismo , Tripsina/metabolismo
18.
Anal Chem ; 87(20): 10199-204, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26399494

RESUMO

Selective enrichment of glycopeptides from complex sample followed by cleavage of N-glycans by PNGase F to expose an easily detectable mark on the former glycosylation sites has become the popular protocol for comprehensive glycoproteome analysis. On account of the high enrichment specificity, hydrazide chemistry based solid-phase extraction of N-linked glycopeptides technique has sparked numerous interests. However, the enzymatic release of glycopeptides captured by hydrazide beads through direct incubation of the beads with PNGase F is not efficient due to the inherent steric hindrance effect. In this study, we developed a hydroxylamine assisted PNGase F deglycosylation (HAPD) method using the hydroxylamine to release glycopeptides captured on the hydrazide beads through the cleavage of hydrazone bonds by transamination followed with the PNGase F deglycosylation of the released glycopeptides in the free solution. Because of the homogeneous condition for the deglycosylation, the recovery of deglycosylated peptides (deglycopeptides) was improved significantly. It was found that 27% more N-glycosylation sites were identified by the HAPD strategy compared with the conventional method. Moreover, the ratio of identified N-terminal glycosylated peptides was improved over 5-fold.


Assuntos
Glicopeptídeos/análise , Hidrazinas/química , Hidroxilamina/química , Peptídeo-N4-(N-acetil-beta-glucosaminil) Asparagina Amidase/metabolismo , Proteoma/análise , Glicopeptídeos/metabolismo , Glicoproteínas/análise , Glicoproteínas/metabolismo , Glicosilação
19.
J Control Release ; 366: 732-745, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38242209

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with high mortality. The Food and Drug Administration-approved drugs, nintedanib and pirfenidone, could delay progressive fibrosis by inhibiting the overactivation of fibroblast, however, there was no significant improvement in patient survival due to low levels of drug accumulation and remodeling of honeycomb cyst and interstitium surrounding the alveoli. Herein, we constructed a dual drug (verteporfin and pirfenidone)-loaded nanoparticle (Lip@VP) with the function of inhibiting airway epithelium fluidization and fibroblast overactivation to prevent honeycomb cyst and interstitium remodeling. Specifically, Lip@VP extensively accumulated in lung tissues via atomized inhalation. Released verteporfin inhibited the fluidization of airway epithelium and the formation of honeycomb cyst, and pirfenidone inhibited fibroblast overactivation and reduced cytokine secretion that promoted the fluidization of airway epithelium. Our results indicated that Lip@VP successfully rescued lung function through inhibiting honeycomb cyst and interstitium remodeling. This study provided a promising strategy to improve the therapeutic efficacy for IPF.


Assuntos
Cistos , Fibrose Pulmonar Idiopática , Nanopartículas , Humanos , Verteporfina , Fibrose Pulmonar Idiopática/tratamento farmacológico , Pulmão
20.
Int J Pharm ; 634: 122637, 2023 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-36702387

RESUMO

Osteosarcoma (OS) is the most common malignant tumor of the bone that affects children and adolescents, and its treatment usually involves doxorubicin hydrochloride (DOX). However, the drug resistance and side effects caused by high-dose DOX infusion greatly hinder its therapeutic effects. To achieve efficient OS treatment with low toxicity, an injectable rhein (RH)-assisted crosslinked hydrogel (PVA@RH@DOX hydrogel, PRDH) was designed, which was prepared by loading DOX and RH into a polyvinyl alcohol (PVA) solution. The cytotoxicity assay and live/dead staining results showed that the combination of RH and DOX more effectively killed OS cells, producing excellent effects at low concentrations of DOX. The wound healing and transwell test results proved that PRDH could significantly inhibit the metastasis and invasion of OS cells. PRDH showed a long-lasting antitumor effect after injection of a single dose, significantly suppressing the proliferation and metastasis of OS and achieving the strategy of a single administration for long-term treatment. Excitingly, RH facilitated hydrogel formation by assisting with PVA crosslinking. This system provides an alternative regimen and broadens the horizon for the clinical treatment of OS.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Criança , Humanos , Adolescente , Hidrogéis/uso terapêutico , Osteossarcoma/tratamento farmacológico , Doxorrubicina/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Linhagem Celular Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA