• 제목/요약/키워드: Protein-based

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A Cell-based Method to Monitor the Interaction between Hepatitis B Virus Capsid and Surface Proteins

  • Kim, Yun-Kyoung;Oh, Soo-Jin;Jin, Bong-Suk;Park, Chan-Hoo;Jeon, Hye Sung;Boo, Doo-Wan;Yu, Yeon-Gyu
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.577-581
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    • 2009
  • Interactions between the surface and capsid proteins of the hepatitis B virus (HBV) are critical for the assembly of virus particles. In this study, we developed a cell-based method to visualize the interactions between the capsid and surface proteins of HBV. Capsid-GFP, a capsid protein fused to a green fluorescence protein (GFP), forms nucleocapsid-like structures in the cytoplasm of mammalian cells. It relocates to the plasma membranes in cells expressing PH-PreS, a fusion protein consisting of the PreS region of the HBV surface protein and the PH domain of PLC-$\gamma$. Membrane localization of the capsid-GFP in these cells is prevented by an inhibitory peptide that blocks the interaction between the capsid and surface proteins. This dynamic localization of capsid-GFP is applicable for screening compounds that may potentially inhibit or prevent the assembly process of HBV particles.

A Comprehensive Review of Recent Advances in the Enrichment and Mass Spectrometric Analysis of Glycoproteins and Glycopeptides in Complex Biological Matrices

  • Mohamed A. Gab-Allah;Jeongkwon Kim
    • Mass Spectrometry Letters
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    • 제15권1호
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    • pp.1-25
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    • 2024
  • Protein glycosylation, a highly significant and ubiquitous post-translational modification (PTM) in eukaryotic cells, has attracted considerable research interest due to its pivotal role in a wide array of essential biological processes. Conducting a comprehensive analysis of glycoproteins is imperative for understanding glycoprotein bio-functions and identifying glycosylated biomarkers. However, the complexity and heterogeneity of glycan structures, coupled with the low abundance and poor ionization efficiencies of glycopeptides have all contributed to making the analysis and subsequent identification of glycans and glycopeptides much more challenging than any other biopolymers. Nevertheless, the significant advancements in enrichment techniques, chromatographic separation, and mass spectrometric methodologies represent promising avenues for mitigating these challenges. Numerous substrates and multifunctional materials are being designed for glycopeptide enrichment, proving valuable in glycomics and glycoproteomics. Mass spectrometry (MS) is pivotal for probing protein glycosylation, offering sensitivity and structural insight into glycopeptides and glycans. Additionally, enhanced MS-based glycopeptide characterization employs various separation techniques like liquid chromatography, capillary electrophoresis, and ion mobility. In this review, we highlight recent advances in enrichment methods and MS-based separation techniques for analyzing different types of protein glycosylation. This review also discusses various approaches employed for glycan release that facilitate the investigation of the glycosylation sites of the identified glycoproteins. Furthermore, numerous bioinformatics tools aiding in accurately characterizing glycan and glycopeptides are covered.

Sensitivity Enhancement of Methyl-TROSY by Longitudinal 1H Relaxation Optimization

  • Lee, Dong-Han;Vijayan, Vinesh;Montaville, Pierre;Becker, Stefan;Griesinger, Christian
    • 한국자기공명학회논문지
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    • 제13권1호
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    • pp.15-26
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    • 2009
  • The NMR detection of methyl groups is of keen interest because they provide the long-range distance information required to establish global folds of high molecular weight proteins. Using longitudinal $^1H$ relaxation optimization, we achieve a gain in sensitivity of approximately 1.6-fold in the methyl-TROSY and its NOESY experiments for the 38 kDa protein mitogen activated protein kinase p38 in its fully protonated and $^{13}C$ and $^{15}N$ labeled state.

단체급식에 관한 연구 (A Study on Group Feeding for Institution)

  • 김혜영
    • 대한가정학회지
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    • 제11권1호
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    • pp.57-74
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    • 1973
  • I. This study on planing menu for group feeding is based on the following ; 1) Decision of nutritive value is based on age, sex, and energy consumption of the students. 2) Selection of food is based on their preference for food through questionaire. 3) Amount of food calorie for each meal is based on data on energy consumption of their daily life. 4) Three data for planing menu for group feeding were based on food rice of each season, favourite foods of girl students and length of their stay at the institution. II. The menu for group feeding was evaluated on nutritive value calorie and protein, 5 basic food groups and price ; 1) The amount of calorie and protein for each season was satisfactory. 2) Each menu was composed of 5 basic food groups but the third group was not satisfactory compared with the other groups. 3) Average price of per day turned out to be 193 won which is less than the standard price, 200 won.

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Meta-analysis of Excision Repair Cross-complementation Group 1 (ERCC1) Association with Response to Platinum-based Chemotherapy in Ovarian Cancer

  • Li, Feng-Ying;Ren, Xiao-Bin;Xie, Xin-You;Zhang, Jun
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7203-7206
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    • 2013
  • Recent studies suggested that the ovarian cancers with negative excision repair cross-complementation group 1 enzyme (ERCC1) expression have a better response to platinum-based chemotherapy than those with positive ERCC1 expression. The objective of this study was to evaluate whether ERCC1 expression is associated with response to platinum-based chemotherapy in ovarian cancers. MEDLINE, PubMed, Web of Science and CNKI databases were used for searching studies relating to ERCC1 protein expression and response to platinum-based chemotherapy in ovarian cancers. Statistical analysis was based on the method for a fixed effects meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals for ERCC1 protein expression and response to platinum-based chemotherapy were generated. Publication bias was investigated with Begg's test. Five studies involving 306 patients with ovarian cancer were included. Compared to patients with positive ERCC1 expression, those with negative ERCC1 expression had a better response to platinum-based chemotherapy. The pooled OR was 5.264 (95% CI: 2.928-9.464, P < 0.001) and publication bias was not found (P = 0.904). The result was similar in both in Asians and Caucasians (P < 0.001 and P = 0.028, respectively). ERCC1 protein expression status is significantly associated with response to platinum-based chemotherapy in ovarian cancers.

Enhanced Induction of T Cell Immunity Using Dendritic Cells Pulsed with HIV Tat and HCMV-pp65 Fusion Protein In Vitro

  • Park, Jung-Sun;Park, Soo-Young;Cho, Hyun-Il;Sohn, Hyun-Jung;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • 제11권3호
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    • pp.182-189
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    • 2011
  • Background: Cytotoxic T lymphocytes (CTLs) appear to play an important role in the control and prevention of human cytomegalovirus (HCMV) infection. The pp65 antigen is a structural protein, which has been defined as a potential target for effective immunity against HCMV infection. Incorporation of an 11 amino acid region of the HIV TAT protein transduction domain (Tat) into protein facilitates rapid, efficient entry into cells. Methods: To establish a strategy for the generation of HCMV-specific CTLs in vitro, recombinant truncated N- and C-terminal pp65 protein (pp65 N&C) and N- and C-terminal pp65 protein fused with Tat (Tat/pp65 N&C) was produced in E.coli system. Peripheral blood mononuclear cells were stimulated with dendritic cells (DCs) pulsed with pp65 N&C or Tat/pp65 N&C protein and immune responses induced was examined using IFN-${\gamma}$ ELISPOT assay, cytotoxicity assay and tetramer staining. Results: DCs pulsed with Tat/pp65N&C protein could induce higher T-cell responses in vitro compared with pp65N&C. Moreover, the DCs pulsed with Tat/pp65 N&C could stimulate both of $CD8^+$ and $CD4^+$ T-cell responses. The T cells induced by DCs pulsed with Tat/pp65 N&C showed higher cytotoxicity than that of pp65-pulsed DCs against autologous lymphoblastoid B-cell line (LCL) expressing the HCMV-pp65 antigen. Conclusion: Our results suggest that DCs pulsed with Tat/pp65 N&C protein effectively induced pp65-specific CTL in vitro. Tat fusion recombinant protein may be useful for the development of adoptive T-cell immunotherapy and DC-based vaccines.

Expression and Characterization of Uropathogenic Escherichia coli Adhesin Protein Linked to Cholera Toxin A2B Subunits in Escherichia coli TB1

  • Lee, Yong-Hwa;Ryu, Dong-Kyun;Kim, Byung-Oh;Pyo, Suhk-Neung
    • Journal of Microbiology and Biotechnology
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    • 제13권4호
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    • pp.552-559
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    • 2003
  • The FimH subunit of type 1-fimbriated Escherichiu coli (E. coli) has been determined as a major cause for urinary tract infections. Thus, to produce a possible vaccine antigen against urinary tract infections, the fimIH gene was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. A fusion protein, based on fusing adhesin to the cholera toxin subunit A2B (CTXA2B), was induced with 0.01 mM isopropyl-${\beta}-D-thiogalactoside$ (IPTG) for 4 h at $37^{\circ}C$ to yield a soluble fusion protein. The fusion protein was then purified by affinity chromatography. The expressed fusion protein was confirmed by SDS-PAGE and Western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was also analyzed. The orderly-assembled fusion protein was confirmed by a modified $G_{Ml}-ganglioside$ ELISA, using antibodies to adhesin. The results indicated that the purified fusion protein was an adhesin/CTXA2B protein containing E. coli adhesin and the $G_{Ml}-ganglioside$ binding activity of CTXB. Accordingly, this adhesin/CTXA2B protein may be a potential antigen for oral immunization against uropathogenic E. coli.

A Fusion Tag to Fold on: The S-Layer Protein SgsE Confers Improved Folding Kinetics to Translationally Fused Enhanced Green Fluorescent Protein

  • Ristl, Robin;Kainz, Birgit;Stadlmayr, Gerhard;Schuster, Heinrich;Pum, Dietmar;Messner, Paul;Obinger, Christian;Schaffer, Christina
    • Journal of Microbiology and Biotechnology
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    • 제22권9호
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    • pp.1271-1278
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    • 2012
  • Genetic fusion of two proteins frequently induces beneficial effects to the proteins, such as increased solubility, besides the combination of two protein functions. Here, we study the effects of the bacterial surface layer protein SgsE from Geobacillus stearothermophilus NRS 2004/3a on the folding of a C-terminally fused enhanced green fluorescent protein (EGFP) moiety. Although GFPs are generally unable to adopt a functional confirmation in the bacterial periplasm of Escherichia coli cells, we observed periplasmic fluorescence from a chimera of a 150-amino-acid N-terminal truncation of SgsE and EGFP. Based on this finding, unfolding and refolding kinetics of different S-layer-EGFP chimeras, a maltose binding protein-EGFP chimera, and sole EGFP were monitored using green fluorescence as indicator for the folded protein state. Calculated apparent rate constants for unfolding and refolding indicated different folding pathways for EGFP depending on the fusion partner used, and a clearly stabilizing effect was observed for the SgsE_C fusion moiety. Thermal stability, as determined by differential scanning calorimetry, and unfolding equilibria were found to be independent of the fused partner. We conclude that the stabilizing effect SgsE_C exerts on EGFP is due to a reduction of degrees of freedom for folding of EGFP in the fused state.