• Title/Summary/Keyword: multimer

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MHC Multimer: A Molecular Toolbox for Immunologists

  • Chang, Jun
    • Molecules and Cells
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    • v.44 no.5
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    • pp.328-334
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    • 2021
  • The advent of the major histocompatibility complex (MHC) multimer technology has led to a breakthrough in the quantification and analysis of antigen-specific T cells. In particular, this technology has dramatically advanced the measurement and analysis of CD8 T cells and is being applied more widely. In addition, the scope of application of MHC multimer technology is gradually expanding to other T cells such as CD4 T cells, natural killer T cells, and mucosal-associated invariant T cells. MHC multimer technology acts by complementing the T-cell receptor-MHC/peptide complex affinity, which is relatively low compared to antigen-antibody affinity, through a multivalent interaction. The application of MHC multimer technology has expanded to include various functions such as quantification and analysis of antigen-specific T cells, cell sorting, depletion, stimulation to replace antigen-presenting cells, and single-cell classification through DNA barcodes. This review aims to provide the latest knowledge of MHC multimer technology, which is constantly evolving, broaden understanding of this technology, and promote its widespread use.

A Statistical Thermodynamic Study on the Conformational Transition of Oligopeptide Multimer

  • Kim, Yong Gu;Park, Hyeong Seok
    • Bulletin of the Korean Chemical Society
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    • v.17 no.2
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    • pp.131-138
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    • 1996
  • The conformational transition of oligopeptide multimer,-(HPPHPPP)n-, is studied (H:hydrophobic amino acid, P:hydrophilic amino acid). The helix/coil transitions are detected in the multimer. The transition depends on the number of amino acid in the sequence, the concentration of the oligopeptide, and temperature which affects helix stability constant (${\xi}$) and hydrophobic interaction parameter (wj). In the thermodynamic equilibrium system jA${\rightarrow}$Aj (where A stands for oligopeptide monomer), Skolnick et al., explained helix/coil transition of dimer by the matrix method using Zimm-Bragg parameters ${\xi}$ and $\sigma$ (helix initiation constant). But the matrix method do not fully explain dangling H-bond effects which are important in oligopeptide systems. In this study we propose a general theory of conformational transitions of oligopeptides in which dimer, trimer, or higher multimer coexists. The partition of trimer is derived by using zipper model which account for dangling H-bond effects. The transitions of multimers which have cross-linked S-S bonds or long chains do not occur, because they keep always helical structures. The transitions due to the concentration of the oligopeptides are steeper than those due to the chain length or temperature.

Adiponectin Gene Cloning and Its Expression in Insect Cell Expression System

  • Yuh, In Suh;Sheffield, Lewis G.
    • Reproductive and Developmental Biology
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    • v.36 no.3
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    • pp.193-198
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    • 2012
  • This study was to examine expression of the recombinant full-length adiponectin (recombinant adiponectin) in insect ovarian cell culture system and to characterize structural properties of the recombinant adiponectin secreted in medium. Gene construct encoding the recombinant adiponectin contained N-terminal collagen-like domain (110 Amino Acids, AAs), C-terminal globular domain (137 AAs) and C-terminal peptides for detection with V5 antibody (26 AAs included adaptor peptide) and purification using the 6xHis tag (6 AAs). The approximate molecular weight of the product (monomer) was 35 kDa. Molecular mass species of the expressed recombinant adiponectin were monomer (~35 kDa), dimer (~70 kDa), trimer (~105 kDa) and hexamer (~210 kDa). The major secreted species were the LMW forms, such as monomer, dimer, and trimer. There was MMW of hexamer as minor form. HMW multimers (~300 kDa) were shown as a tracer or not detected on the SDS-PAGE in several experiments (data not shown). The multimer forms in this study were not compatible to those in animal or human serum and adipose tissue by other researcher's study in which the major multimer forms were HMW. By protein denaturing experiments with reducing reagent (${\beta}$-MeOH), anionic detergent (SDS) and heat ($95^{\circ}C$) on the SDS-PAGE, not all adiponectin multimers seemed to have disulfide bond linked structure to form multimers. The recombinant adiponectin which expressed in insect ovarian cell culture system seemed to have the limitation as full physiological regulator for the application to animal and human study.

Design and Expression of Recombinant Antihypertensive Peptide Multimer Gene in Escherichia coli BL21

  • Rao, Shengqi;Su, Yujie;Li, Junhua;Xu, Zhenzhen;Yang, Yanjun
    • Journal of Microbiology and Biotechnology
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    • v.19 no.12
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    • pp.1620-1627
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    • 2009
  • The design and expression of an antihypertensive peptide multimer (AHPM), a common precursor of 11 kinds of antihypertensive peptides (AHPs) tandemly linked up according to the restriction sites of gastrointestinal proteases, were explored. The DNA fragment encoding the AHPM was chemically synthesized and cloned into expression vector pGEX-3X. After an optimum induction with IPTG, the recombinant AHPM fused with glutathione S-transferase (GST-AHPM) was expressed mostly as inclusion body in Escherichia coli BL21 and reached the maximal production, 35% of total intracellular protein. The inclusion body was washed, dissolved, and purified by cation-exchange chromatography under denaturing conditions, followed by refolding together with size-exclusion chromatography and gradual dialysis. The resulting yield of the soluble GSTAHPM (34 kDa) with a purity of 95% reached 399 mg/l culture. The release of high active fragments from the AHPM was confirmed by the simulated gastrointestinal digestion. The results suggest that the design strategy and production method of the AHPM will be useful to obtain a large quantity of recombinant AHPs at a low cost.

Reductive Depolymerization of Bovine Thyroglobulin Multimers via Enzymatic Reduction of Protein Disulfide and Glutathiony­lated Mixed Disulfide Linkages

  • Liu Xi-Wen;Sok Dai-Eun
    • Archives of Pharmacal Research
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    • v.28 no.9
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    • pp.1065-1072
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    • 2005
  • The nascent thyroglobulin (Tg) multimer molecule, which is generated during the initial fate of Tg in ER, undergoes the rapid reductive depolymerization. In an attempt to determine the depolymerization process, various types of Tg multimers, which were generated from deoxy­cholate-treated/reduced Tg, partially unfolded Tg or partially unfolded/reduced Tg, were subjected to various GSH (reduced glutathione) reducing systems using protein disulfide isomerase (PDI), glutathione reductase (GR), glutaredoxin or thioredoxin reductase. The Tg multimers generated from deoxycholate-treated/reduced Tg were depolymerized readily by the PDI/GSH system, which is consistent with the reductase activity of PDI. The PDI/GSH-induced depolymerization of the Tg multimers, which were generated from either partially unfolded Tg or partially unfolded/reduced Tg, required the simultaneous inclusion of glutathione reductase, which is capable of reducing glutathionylated mixed disulfide (PSSG). This suggests that PSSG was generated during the Tg multimerization stage or its depolymerization stage. In particular, the thioredoxin/thioredoxin reductase system or glutaredoxin system was also effective in depolymerizing the Tg multimers generated from the unfolded Tg. Overall, under the net GSH condition, the depolymerization of Tg multimers might be mediated by PDI, which is assisted by other reductive enzymes, and the mechanism for depolymerizing the Tg multimers differs according to the type of Tg multimer containing different degrees and types of disulfide linkages.

Purification of Recombinant CTP-Conjugated Human prostatic acid phosphatase for activation of Dendritic Cell (수지상세포 활성화를 위한 세포투과 펩타이드가 결합된 재조합 전립성 산성 인산분해효소의 정제)

  • Yi, Ki-Wan;Ryu, Kang
    • KSBB Journal
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    • v.24 no.1
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    • pp.80-88
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    • 2009
  • Human prostatic acid phosphatase (PAP), with comprehensive homology to glandular kallikrein, are representative serum biomarkers of prostate cancer. Dendritic cell (DC), which is the potent antigen-presenting cells(APC) in the immune system, can induce strong T cell responses against viruses, microbial pathogens, and tumors. Therefore, the immunization using DC loaded with tumor-associated antigens is a powerful method for inducing anti-tumor immunity. The CTP (Cytoplasmic Transduction Peptide) technology developed by Creagene which can transport attached bio-polymers like nucleic acids or proteins into the cell with high permeation efficiency. As the active forms of PAP can mediate apoptotic processing, we used multimer forms of PAP as an inactive form for antigen pulsing of DCs. In this study, multimeric forms of CTP-rhPAP was obtained according to the advanced purification process and subsequently confirmed by gel filtration chromatography, western blot and Dynamic Light Scattering. Therefore, CTP-conjugated PA multimers transduced into the cytoplasm were efficiently presented on the cell surface without any harm effect on cells via MHC class I molecules and result in induction of a large number of effector cell.

Characteristics of Structural Proteins of Synechococcus sp. Cyanophage (Synechoscoccus sp. cyanophage 구조단백질의 특성)

  • Kim, Seung-Won;Kim, Min;Leem, Mi-Hyea;Choi, Yong-Keel
    • Korean Journal of Microbiology
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    • v.33 no.4
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    • pp.242-246
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    • 1997
  • The protein profile of Synechococcus sp. cyanophage was investigated employing SDS-PAGE. The phage appears to be composed of two major proteins of 97 and 52 kDa and at least seven minor proteins of 70, 65, 60, 40, 35, 28, and 6 kDa. It seems that each subunit is combined to form a multimer although any disulfide bond does not exist in the phage structure. Lytic activity of the phage particle against cell wall was detected around the 52 kDa on renaturing SDS-PAGE using heat-killed Micrococcus luteus cells as substrate. The activity has the optimal pH between 9 and 10, and slightly inhibited by EDTA.

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Interaction of FERM Domain of Tumor Suppressor, Merlin to its C-terminal Domain. (종양 억제 인자, Merlin의 FERM 도메인과 C-말단 도메인간의 결합)

  • Oh, Jeong-Il;Kang, Beom-Sik
    • Journal of Life Science
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    • v.17 no.9 s.89
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    • pp.1303-1307
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    • 2007
  • A tumor suppressor, merlin is a member of ERM family proteins. It consists of N-terminal FERM domain, ${\alpha}-helical$ region, and C-terminal domain. Alternative splicing of merlin's mRNA generates two isotypes of merlin. Isotype I, which has exon17 at the C-terminus instead of exon16 in isotype II, is known to have tumor suppressor activity. Like other ERM proteins, the C-terminal domain of merlin isotype I interacts to its FERM domain. That of isotype II, however, was reported not to bind FERM domain despite the large common part of C-terminal domain, which possibly binds FERM domain. Here, we show the binding of FERM domain to both C-terminal domains of merlin's two isotypes by isothermal titration calorimetry. These results support that merlin isotype II also can form a closed conformation or a multimer by intramolecular or intermolecular interactions using their FERM domain and C-terminal domain.

Biological Activity and Acute Toxicity of the Multimers of CJ500011 Recombinant Human Granulocyte Colony-stimulating Factor (rHuG-CSF), Produced in E. coli (재조합 사람 과립구 콜로니 자극인자인 C,J50001의 중합체의 생물학적 활성과 급성독성에 관한 연구)

  • 하석훈;이현수;김기완;정종상;김달현
    • Biomolecules & Therapeutics
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    • v.6 no.1
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    • pp.89-94
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    • 1998
  • CJ50001 is a recombinant human granulocyte colony-stimulating facto, (rHuG-CSF) that stimulates the formation of neutrophils from bone marrow stem cells. It was produced in E. colt and purified through refolding and several processes. We produced CS970125(300) using purified C150001 and additives in order to test the stability of CJ50001. When CS970125(300) was stored at 50'S for more than 1 week, high molecular weight proteins were formed and those proteins were detected by non-reducing SDS-PAGE, gel filtration HPLC, and Western blot. Those proteins showed single band at the same position of CJ50001 in reducing SDS-PAGE. These data indicated that those high molecular weight proteins were the multimers of C150001. In biological assays, iu viro and in viro, the multimers did not have biological activity and inhibitory action to that of CJ 50001. The mutimers did not induce toxicity in mice and rats in acute toxicity test. These results suggest that if Cs970125(300) containing CJ50001 is stored at 5$0^{\circ}C$, CJ50001 will be the multimers that do not have biological activity and inhibitory effect to CJ50001 and do not induce acute toxicity.

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