Publications by authors named "Xiangchun Wang"

Even after a long time of polymer flooding, over half of the crude oil is still trapped in the reservoir due to the poor plugging capacity. It has been demonstrated that fuzzy-ball fluid can be utilized as an effective plugging fluid. The idea of further increasing oil recovery by fuzzy-ball fluid following polymer flooding drew us to investigate it due to its high performance and effect.

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Antibody 10E8 is capable of effectively neutralizing HIV through its recognition of the membrane-proximal external region (MPER), and a suitably optimized version of 10E8 might have utility in HIV therapy and prophylaxis. However, 10E8 displays a three-peak profile on size-exclusion chromatography (SEC), complicating its manufacture. Here we show cis-trans conformational isomerization of the Tyr-Pro-Pro (YPP) motif in the heavy chain 3rd complementarity-determining region (CDR H3) of antibody 10E8 to be the mechanistic basis of its multipeak behavior.

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One of the HIV-1 vaccine design efforts has focused on developing a recombinant HIV-1 trimeric envelope glycoprotein (Env) as an immunogen to induce broadly neutralizing antibodies. A native-like immunogen, the BG505.DS.

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Quantitative measurement of process-related impurities is a critical safety requirement for the production of drug substances of vaccine and therapeutic biologics. A simple and sensitive HPLC method has been developed for separation and quantitation of residual valproic acid (VPA) used in the cell transfection procedure for the manufacturing of an influenza vaccine. The method is comprised of a modified Dole liquid phase extraction followed by a quick pre-column derivatization using 2-bromoacetophenone.

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Heavy metals contaminated sediment has become a worldwide environmental issue due to its great harm to human and aquatic organisms. Thus, economical, effective, and environmentally-friendly remediation technologies are urgently needed. Among which, combined remediation technologies have attracted widespread attention for their unique advantages.

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A hemagglutinin stabilized stem nanoparticle (HA-SS-np) that is designed to provide broad protection against influenza is being developed as a potential vaccine. During an early formulation screening study, reducing gel (rCGE) analysis indicated product degradation in a few candidate buffers at the first-week accelerated stability point, whereas no change was shown in the size exclusion chromatography (SEC) measurement. A LC-MS workflow was therefore applied to investigate the integrity of this large HA-SS-np vaccine molecule (≈ 1 MDa).

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10E8 is a potent broadly neutralizing antibody (bNAb) that targets the membrane-proximal external region (MPER) of the HIV virus. During early analytical development of this bNAb directed towards clinical evaluation, 10E8 exhibited a multiple-monomeric-peak profile caused by secondary interactions in traditional size-exclusion chromatography (SEC), thereby rendering SEC unfit for the purpose of assessing aggregation, a target critical quality attribute. To overcome this challenge, an innovative and robust SEC method was successfully developed in which the mobile phase was tested for excipients capable of reducing the secondary interactions responsible for the multipeak profile, and an optimal mobile phase composed of 2× PBS and 100 mM arginine at pH 10.

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Prostate cancer is the most common cancer among men in the U.S. and worldwide, and androgen-deprivation therapy remains the principal treatment for patients.

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Aberrant glycosylation is associated with most of the diseases. Direct imaging and profiling of N-glycans on tissue sections can reveal tissue-specific and/or disease-associated N-glycans, which not only could serve as molecular signatures for diagnosis but also shed light on the functional roles of these biomolecules. Mass spectrometry imaging (MSI) is a powerful tool that has been used to correlate peptides, proteins, lipids, and metabolites with their underlying histopathology in tissue sections.

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Aberrant protein glycosylation is known to be associated with the development of cancers. The aberrant glycans are produced by the combined actions of changed glycosylation enzymes, substrates and transporters in glycosylation synthesis pathways in cancer cells. To identify glycosylation enzymes associated with aggressive prostate cancer (PCa), we analyzed the difference in the expression of glycosyltransferase genes between aggressive and non-aggressive PCa.

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Background: Lung cancer is the number one cause of cancer-related deaths in the United States and worldwide. The complex protein changes and/or signature of protein expression in lung cancer, particularly in non-small cell lung cancer (NSCLC) has not been well defined. Although several studies have investigated the protein profile in lung cancers, the knowledge is far from complete.

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Smad ubiquitin regulatory factors (Smurfs) are HECT-domain ubiquitin E3 ligases that regulate diverse cellular processes, including normal and tumor cell migration. However, the underlying mechanism of the Smurfs' role in cell migration is not fully understood. Here we show that Smurf1 induces ubiquitination of tumor necrosis factor receptor-associated factor 4 (TRAF4) at K190.

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TGF-β signalling is regulated by post-translational modifications of Smad proteins to translate quantitative difference in ligand concentration into proportional transcriptional output. Previous studies in cell culture systems suggested that Smad ubiquitination regulatory factors (Smurfs) act in this regulation by targeting Smads for proteasomal degradation, but whether this mechanism operates under physiological conditions is not clear. Here, we generated mice harbouring a target-disrupted Smurf2 allele.

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alpha1,6-Fucosylation plays key roles in many biological functions, as evidenced by the study of alpha1,6-fucosyltransferase (Fut8) knockout (Fut8(-/-)) mice. Phenotypically, Fut8(-/-) mice exhibit emphysema-like changes in the lung, and severe growth retardation. Fut8(-/-) cells also show marked dysregulation of the TGF-beta1 receptor, EGF receptor, integrin activation and intracellular signalling, all of which can be rescued by reintroduction of Fut8.

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Controlled protein degradation mediated by ubiquitin/proteasome system (UPS) plays a crucial role in modulating a broad range of cellular responses. Dysregulation of the UPS often accompanies tumorigenesis and progression. Here, we report that Smad ubiquitination regulatory factor 2 (Smurf2), a HECT-domain containing E3 ubiquitin ligase, is up-regulated in certain breast cancer tissues and cells.

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Article Synopsis
  • TGF-beta plays a crucial role in various physiological and disease processes by interacting with MAP kinase pathways and Smads, influencing apoptosis and the epithelial-to-mesenchymal transition.
  • The study identifies TRAF6 as essential for the Smad-independent activation of the JNK and p38 MAP kinase pathways, showing it interacts physically with TGF-beta receptors.
  • TGF-beta triggers K63-linked ubiquitination of TRAF6, enhancing its association with TAK1, indicating that TGF-beta activates JNK and p38 through mechanisms akin to those seen in the interleukin-1beta/Toll-like receptor pathway.
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Mice with a targeted gene disruption of Fut8 (Fut8(-/-)) showed an abnormality in the transition from pro-B cell to pre-B cell, reduced peripheral B cells, and a decreased immunoglobulin production. Alpha 1,6-fucosyltransferase (FUT8) is responsible for the alpha 1,6 core fucosylation of N-glycans, which could modify the functions of glycoproteins. The loss of a core fucose in both very late antigen 4 (VLA-4, alpha4beta1 integrin) and vascular cell adhesion molecule 1 (VCAM-1) led to a decreased binding between pre-B cells and stromal cells, which impaired pre-B cells generation in Fut8(-/-) mice.

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The alpha1,6-fucosyl residue (core fucose) of glycoproteins is widely distributed in mammalian tissues and is altered under pathological conditions. A probe that specifically detects core fucose is important for understanding the role of this oligosaccharide structure. Aleuria aurantia lectin (AAL) and Lens culimaris agglutinin-A (LCA) have been often used as carbohydrate probes for core fucose in glycoproteins.

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Comprehensive analyses of proteins from cells and tissues are the most effective means of elucidating the expression patterns of individual disease-related proteins. On the other hand, the simultaneous separation and characterization of proteins by 1-DE or 2-DE followed by MS analysis are one of the fundamental approaches to proteomic analysis. However, these analyses do not permit the complete structural identification of glycans in glycoproteins or their structural characterization.

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Mammalian alpha1,6-fucosyltransferase (FUT8) catalyses the transfer of a fucose residue from a donor substrate, guanosine 5'-diphosphate-beta-L-fucose to the reducing terminal N-acetylglucosamine (GlcNAc) of the core structure of an asparagine-linked oligosaccharide. Alpha1,6-fucosylation, also referred to as core fucosylation, plays an essential role in various pathophysiological events. Our group reported that FUT8 null mice showed severe growth retardation and emphysema-like lung-destruction as a result of the dysfunction of epidermal growth factor and transforming growth factor-beta receptors.

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Alpha1,6-fucosyltransferase (Fut8) catalyzes the transfer of a fucose residue to N-linked oligosaccharides on glycoproteins by means of an alpha1,6-linkage to form core fucosylation in mammals. In mice, disruption of Fut8 induces severe growth retardation, early death during postnatal development, and emphysema-like changes in the lung. A marked dysregulation of TGF-beta1 receptor activation and signaling in Fut8-null mice lung results in overexpression of matrix metalloproteinases (MMPs), such as MMP12 and MMP13, and a down-regulation of extracellular matrix (ECM) proteins such as elastin, which contributes to the destructive emphysema-like phenotype observed in Fut8-null mice.

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The core fucosylation (alpha1,6-fucosylation) of glycoprotein is widely distributed in mammalian tissues. Recently alpha1,6-fucosylation has been further reported to be very crucial by the study of alpha1,6-fucosyltransferase (Fut8)-knock-out mice, which shows the phenotype of emphysema-like changes in the lung and severe growth retardation. In this study, we extensively investigated the effect of core fucosylation on alpha3beta1 integrin and found for the first time that Fut8 makes an important contribution to the functions of this integrin.

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Alpha1,6-fucosyltransferase (Fut8) plays important roles in physiological and pathological conditions. Fut8-deficient (Fut8-/-) mice exhibit growth retardation, earlier postnatal death, and emphysema-like phenotype. To investigate the underlying molecular mechanism by which growth retardation occurs, we examined the mRNA expression levels of Fut8-/- embryos (18.

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alpha1,6-Fucosyltransferase (Fut8) catalyzes the transfer of a fucose residue from GDP-fucose to the innermost N-acetylglucosamine residue of N-glycans. Here we report that the loss of core fucosylation impairs the function of low-density lipoprotein (LDL) receptor-related protein-1 (LRP-1), a multifunctional scavenger and signaling receptor, resulting in a reduction in the endocytosis of insulin like growth factor (IGF)-binding protein-3 (IGFBP-3) in the cells derived from Fut8-null (Fut8-/-) mice. The reduced endocytosis was restored by the re-introduction of Fut8.

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Changes in oligosaccharide structures are associated with numerous physiological and pathological events. In this study, the effects of cell-cell interactions on N-linked oligosaccharides (N-glycans) were investigated in GE11 epithelial cells. N-glycans were purified from whole cell lysates by hydrazinolysis and then detected by high performance liquid chromatography and mass spectrometry.

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