• Journal of Industrial Technology
• /
• v.40 no.1
• /
• pp.1-6
• /
• 2020

In the process of protein transcription and translation, various protein complexes bind to DNA, and all processes are precisely controlled. Among the proteins constituting this complex, a peptide derived from eukaryotic initiation factor (eIF) 2 was synthesized. In addition, in order to increase the efficiency of transduction of this peptide into cells, peptides with polyarginine, one of the protein transduction domains (PTD), were synthesized. Cell growth inhibition was confirmed in HER2 positive breast cancer (SK-Br-3) and HER2 negative breast cancer (MDA-MB-231), and cardiomyocytes (H9c2). The peptide with polyarginine had high transduction efficiency in all cells, and had excellent cancer cell growth inhibitory effects. The peptide used in this study might be useful peptide therapeutics for the treatment of cancer through future research.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2004.06a
• /
• pp.249-249
• /
• 2004

• BMB Reports
• /
• v.43 no.9
• /
• pp.609-613
• /
• 2010

The Dvl and Axin proteins, which are involved in the Wnt signaling pathway, each contain a conserved DIX domain in their sequences. The DIX domain mediates interaction between Dvl and Axin, which together play an important role in signal transduction. However, the extremely low production of DIX domain fragments in E. coli has prevented more widespread functional and structural studies. In this study, we demonstrate that the DIX domains of Dvl and Axin are expressed noticeably in a multi-cistronic system but not in a mono-cistronic system. Formation of the $DIX_{Dvl1}-DIX_{Axin1}$ complex was investigated by affinity chromatography, SEC and crystallization studies. Unstable DIX domains were stabilized by complexing with counterpart DIX domains. The results of the preliminary crystallization and diffraction of the $DIX_{Dvl1}-DIX_{Axin1}$ complex may prove useful for further crystallographic studies.

• BMB Reports
• /
• v.43 no.8
• /
• pp.561-566
• /
• 2010

Though protein transduction domains (PTDs) are well known for the delivery of exogenous therapeutic proteins into living cells, the overall low efficiency of transduction is a serious obstacle. We investigated the effect of bog blueberry anthocyanins (BBA) on protein transduction efficiency and found that BBA enhanced the transduction efficiencies of Tat-SOD fusion protein into HeLa cells and mice skin. The enzymatic activities in the cells and skin tissue in the presence of BBA were markedly increased compared to controls. Further, BBA did not demonstrate any cell toxicity at various concentrations. Although the mechanism is not fully understood, we suggest that BBA might alter the conformation of the membrane, which would indicate that BBA can be used as a protein transduction enhancer for the efficient delivery of therapeutic proteins for a variety of disorders.

• BMB Reports
• /
• v.31 no.4
• /
• pp.370-376
• /
• 1998

Src-Homology 2 (SH2) domains have a capacity to bind phosphotyrosine-containing sequence context and play essential roles in various cellular signaling pathways. Due to the specific nature of the binding between SH2 domains and their counterpart proteins, inhibitors of SID domain binding have drawn extensive attention as a potential candidate for therapeutic agents. Here, we describe the binding assay system to screen for the ligands or blockers of the SH2 domains with an emphasis on the $p56^{lck}$ SH2 domain. In our assay system, SID domains expressed and purified as fusion proteins to Glutathione-S-transferase (GST) were covalently attached to 96-well microtitre plates through amide bond formation, which were subsequently allowed to bind the biotinylated phosphotyrosine (pY)containing synthetic pep tides. The binding of biotinylated pY peptides was detected by the horseradish peroxidase (HRP)-conjugated streptavidin. Using the various combinations of SH2 domain-pY peptides, we observed that: (1) The binding of pY-peptides to its counterpart SH2 domain is concentration-dependent and saturable; (2) The binding is highly specific for a particular combination of SH2 domain-pY peptide pair; and (3) The binding of Lck SH2-cognate pY-peptides is specifically competed by the nonbiotinylated peptides with expected relative affinity. These results indicate that the established assay system detects the SH2-pY peptide interaction with reproducible sensitivity and specificity and is suitable for screening the specific inhibitors of $p56^{lck}$ SH2 function.

• BMB Reports
• /
• v.45 no.12
• /
• pp.693-699
• /
• 2012

Together with protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs) serve as hallmarks in cellular signal transduction by controlling the reversible phosphorylation of their substrates. The human genome is estimated to encode more than 100 PTPs, which can be divided into eleven sub-groups according to their structural and functional characteristics. All the crystal structures of catalytic domains of sub-groups have been elucidated, enabling us to understand their precise catalytic mechanism and to compare their structures across all sub-groups. In this review, I describe the structure and mechanism of catalytic domains of PTPs in the structural context.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.47-50
• /
• 2002

Raft is a distinctive membrane domain enriched in a certain class of lipids, cholesterol, and proteins observed on the plasma membrane. Growing evidence has revealed that such membrane domains play key roles in signal transduction, fertilization, development, transmitter release, and so on. Recently, we have isolated raft-like detergent-resistant membrane (DRM) fraction from bovine photoreceptor rod outer segments. Transducin and its effecter, cGMP-phosphodiesterase, elicited stimulus-dependent translocation between detergent-soluble membrane and DRM. This suggested potential importance of such distinct membrane domains in vertebrate phototransduction. Here, we will discuss physiological meaning of the translocation of major components of cGMP cascade to raft-like membrane in phototransduction. We would like to propose a hypothesis that raft-like membrane domains on the disk membrane are the place where cGMP cascade system could be quenched.

• Molecules and Cells
• /
• v.19 no.2
• /
• pp.191-197
• /
• 2005

The human immunodeficiency virus type 1 (HIV-1) Tat protein transduction domain (PTD) is responsible for highly efficient protein transduction across plasma membranes. In a previous study, we showed that Tat-Cu,Zn-superoxide dismutase (Tat-SOD) can be directly transduced into mammalian cells across the lipid membrane barrier. In this study, we fused the human SOD gene with a Tat PTD transduction vector at its N- and/or C-terminus. The fusion proteins (Tat-SOD, SOD-Tat, Tat-SOD-Tat) were purified from Escherichia coli and their ability to enter cells in vitro and in vivo compared by Western blotting and immunohistochemistry. The transduction efficiencies and biological activities of the SOD fusion protein with the Tat PTD at either terminus were equivalent and lower than the fusion protein with the Tat PTD at both termini. The availability of a more efficient SOD fusion protein provides a powerful vehicle for therapy in human diseases related to this anti-oxidant enzyme and to reactive oxygen species.

• BMB Reports
• /
• v.44 no.5
• /
• pp.329-334
• /
• 2011

Many proteins with poor transduction efficiency were reported to be delivered to cells by fusion with protein transduction domains (PTDs). In this study, we investigated the effect of levosulpiride on the transduction of PEP-1 ribosomal protein S3 (PEP-1-rpS3), and examined its influence on the stimulation of the therapeutic properties of PEP-1-rpS3. PEP-1-rpS3 transduction into HaCaT human keratinocytes and mouse skin was stimulated by levosulpiride in a manner that did not directly affect the cell viability. Following 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice, levosulpiride alone was ineffective in reducing TPA-induced edema and in inhibiting the elevated productions of inflammatory mediators and cytokines, such as cyclooxygenase-2, inducible nitric oxide synthase, interleukin-6 and -1${\beta}$, and tumor necrosis factor-${\alpha}$. Anti-inflammatory activity by PEP-1-rpS3 + levosulpiride was significantly more potent than by PEP-1-rpS3 alone. These results suggest that levosulpiride may be useful for enhancing the therapeutic effect of PEP-1-rpS3 against various inflammatory diseases.

• Journal of Pharmaceutical Investigation
• /
• v.34 no.2
• /
• pp.101-106
• /
• 2004

This work aims at examining the cellular uptake behavior of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles derivatized with a protein transduction domain (PTD) using HeLa cells. For this purpose, $Tat_{49-57}$ peptide derived from transcriptional activation (Tat) protein of HIV type-1 was covalently conjugated to the terminal end of PLGA. Nanoparticles were ten prepared with the $Tat_{49-57}-PLGA$ conjugates by a spontaneous phase inversion method. The prepared particles had a mean diameter of ca. 84 nm, as measured by dynamic light scattering. The interaction of the Tat-PLGA nanoparticles with cells was examined by using confocal laser scanning microscopy. It was found tat Tat-PLGA nanoparticles incubated with HeLa cells could efficiently translocate into cytoplasm, while plain PLGA nanoparticles showed negligible cellular uptake. In addition, even at $4^{\circ}C$ or in the presence of sodium azide significant cellular internalization of Tat-PLGA nanoparticles was still observed. These results indicate that a non-endocytotic translocation mechanism might be involved in the cellular uptake of Tat-PLGA nanoparticles.