Publications by authors named "Sunggun Kim"

This study presents a novel method for encapsulating the bioactive peptide teduglutide to enhance its oral bioavailability using O/W nanoemulsion (NE). Recombinant teduglutide (rTGT), produced in E. coli with 93 % purity, was hydrophobically modified through ion-pairing with phytic acid (PA) and sodium dodecyl sulfate (SDS).

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has traditionally been used as an antipyretic, analgesic, and anti-inflammatory agent and as a treatment for uterine and anal prolapse. This study has investigated the potential beneficial effects of this medicinal plant and its components on Alzheimer's disease (AD) with a focus on amyloid beta (Aβ) production and scopolamine-induced memory impairment in mice. An ethanol extract from roots decreased Aβ production in APP-CHO cells [Chinese hamster ovarian (CHO) cells stably expressing amyloid precursor protein (APP)], as determined by an enzyme-linked immunosorbent assay and Western blot analysis.

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Nascent polypeptides are synthesized on ribosomes starting at the N-terminus and simultaneously begin to fold during translation. We constructed N-terminal fragments of prosubtilisin E containing an intramolecular chaperone (IMC) at N-terminus to mimic cotranslational folding intermediates of prosubtilisin. The IMC-fragments of prosubtilisin exhibited progressive enhancement of their secondary structures and thermostabilities with increasing polypeptide length.

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Alzheimer's disease (AD) is a progressive, neurodegenerative brain disorder associated with loss of memory and cognitive function. Beta-amyloid (Aβ) aggregates, in particular, are known to be highly neurotoxic and lead to neurodegeneration. Therefore, blockade or reduction of Aβ aggregation is a promising therapeutic approach in AD.

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Cynandione A (CA), isolated from ethyl acetate extract of Cynanchum wilfordii (CW), is a bioactive phytochemical that has been found to be beneficial for the treatment of several diseases. Hepatic de novo lipogenesis is one of the main causes of non-alcoholic fatty liver disease (NAFLD), which is thought to be a hepatic manifestation of certain metabolic syndromes. However, it has not yet been reported if CA has any therapeutic value in these diseases.

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Background: T helper 17 (Th17) cells, which are differentiated from CD4 T cells, drive inflammation, leading to autoimmune diseases such as psoriasis, rheumatoid arthritis, and inflammatory bowel disease. Therefore, inhibiting Th17 polarization could be a therapeutic target for inflammatory diseases.

Purpose: We investigated the inhibitory effect of Fraxinus rhynchophylla (Oleaceae) on Th17 differentiation and found its active component.

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Molecules interfering with lipid bilayer function exhibit strong antiviral activity against a broad range of enveloped viruses, with a lower risk of resistance development than that for viral protein-targeting drugs. Amphipathic peptides are rich sources of such membrane-interacting antivirals. Here, we report that influenza viruses were effectively inactivated by M2 AH, an amphipathic peptide derived from the M2 protein of the influenza virus.

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The arial parts of Scutellaria barbata D. Don (Lamiaceae) efficiently inhibited NO production in BV2 microglial cells, and the active constituents were further isolated based on activity-guided isolation using silica-gel column chromatography, RP-C18 MPLC and prep-HPLC. As the results, 2 flavonoids including 6-methoxynaringenin (1) and 6-O-methylscutellarein (5), and 6 neo-clerodane diterpenes such as scutebarbatine W (2), scutebatas B (3), scutebarbatine B (4), scutebarbatine A (6), 6-O-nicotinolylscutebarbatine G (7), and scutebarbatine X (8) were isolated.

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Many bacteria have toxin-antitoxin (TA) systems, where toxin gene expression inhibits their own cell growth. mRNA is one of the well-known targets of the toxins in the type II toxin-antitoxin systems. Here, we examined the ribosome dependency of the endoribonuclease activity of YhaV, one of the toxins in type II TA systems, on mRNA in vitro and in vivo.

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Article Synopsis
  • Der is a crucial GTPase in E. coli that aids in the formation of stable 50S ribosomal subunits, with its absence leading to structural instability.
  • Cloning and testing Der homologs from various bacteria showed that only those from Klebsiella pneumoniae and Salmonella enterica could compensate for the E. coli Der deficiency, restoring growth and ribosomal stability.
  • The study suggests that specific regions of the Der protein may be key for functional performance in different bacterial species, highlighting its evolutionary conservation and role in ribosomal biosynthesis.
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Article Synopsis
  • Aflatoxin B1 (AFB1) is a potent carcinogen found in food and feed, highlighting the need for effective detection methods through high-affinity antibodies.
  • Previously developed scFv-M37, with 6 mutations, showed significantly improved binding to AFB1.
  • The study found that reverting one of the mutations (VH-A110T) enhanced binding affinity further by improving the structure of the antibody, leading to more effective detection of AFB1.
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CspA has been identified as a major cold-shock protein in Escherichia coli. CspA binds to RNAs which are abnormally folded at low temperature and then acts as an RNA chaperone unfolding those RNAs. The dramatic expression of cspA at low temperature is contributed by posttranscriptional stability and robust translatability.

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As aflatoxin B1 is one of the most toxic mycotoxins, it is important to detect and to quantify aflatoxin B1 accurately by immunological methods. To enhance aflatoxin B1-binding affinity of the single-chain variable fragment, yeast surface display technique combined with fluorescence-activated cell sorting was applied. A randomly mutated scFv library was subjected to 4 rounds of fluorescence-activated cell sorting, resulting in isolation of 5 scFv variants showing an affinity improvement compared to the parental wild type scFv.

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Flow and dynamic rheological properties of hot thickened soups for consumption by the elderly people with swallowing difficulty (dysphagia) were investigated at a serving temperature of 60°C. In this study, sea mustard soup (SMS) and dried pollock soup (DPS), which have been widely known as favorable hot soups provided in a domestic hospitals and nursing homes for dysphagic patients, were thickened with four commercial xanthan gum (XG)-based food thickeners (coded A~D) marketed in Korea. Thickened soups prepared with different thickeners showed high shear-thinning flow behaviors (n=0.

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Article Synopsis
  • The study investigates how the setting time affects the viscosity of cold-thickened beverages made with xanthan gum-based thickeners at 5°C.
  • Different setting times (15-120 min) were tested on four commercially available thickeners mixed with three types of beverages (water, orange juice, milk) using a rheometer to measure viscosity changes.
  • Results showed that viscosity increased significantly at 15 minutes, particularly in beverages other than water, with thickened orange juice and milk showing more stability with thickener A over time.
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The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.

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Receptor activator of nuclear factor-kappa B ligand (RANKL) is a critical factor in osteoclastogenesis. It makes osteoclasts differentiate and multinucleate in bone remodeling. In the present study, RANKL was expressed as a soluble maltose binding protein (MBP)-fusion protein using the Escherichia coli maltose binding domain tag system (pMAL) expression vector system.

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Background: Nanoparticles undergoing physicochemical changes to release enclosed drugs at acidic pH conditions are promising vehicles for antitumor drug delivery. Among the various drug carriers, high-density lipoprotein (HDL)-like nanoparticles have been shown to be beneficial for cancer chemotherapy, but have not yet been designed to be pH-responsive.

Methods And Results: In this study, we developed a pH-responsive HDL-like nanoparticle that selectively releases paclitaxel, a model antitumor drug, at acidic pH.

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In an attempt to produce glucagon-like peptide-1 (GLP-1) using recombinant Escherichia coli, ubiquitin (Ub) as a fusion partner was fused to GLP-1 with the 6-lysine tag (K6) for simple purification. Despite the high solubility of ubiquitin, the fusion protein K6UbGLP-1 was expressed mainly as insoluble inclusion bodies in E. coli.

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Human glucagon-like peptide-1 (GLP-1), an incretin hormone with pharmaceutical potential in treating type 2 diabetes mellitus is known to be rapidly degraded when expressed in Escherichia coli. For the efficient production of the intact GLP-1 using a recombinant E. coli system, a fusion protein of GLP-1 was designed to be composed of the 6-lysine tag, ubiquitin and GLP-1 (K6UbGLP-1) in a row.

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In the Single Protein Production (SPP) method, all E. coli cellular mRNAs are eliminated by the induction of MazF, an ACA-specific mRNA interferase. When an mRNA for a membrane protein, engineered to have no ACA sequences without altering its amino acid sequence, is induced in the MazF-induced cells, E.

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Oxaliplatin and irinotecan have proven effective in the treatment of gastric cancer. We attempted to determine whether single nucleotide polymorphisms in ERCC1, GST, TS and UGT1A1 predicted overall survival in gastric cancer patients receiving FOLFOX and/or FOLFIRI chemotherapy. Total genomic DNA was extracted from the whole blood of patients.

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Background: Escherichia coli has been most widely used for the production of valuable recombinant proteins. However, over-production of heterologous proteins in E. coli frequently leads to their misfolding and aggregation yielding inclusion bodies.

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The YUH1 gene coding for ubiquitin C-terminal hydrolase 1, a deubiquitinating enzyme, was cloned from the Saccharomyces cerevisiae genomic DNA and expressed in Escherichia coli. YUH1 was fused with the 6 histidine tag at the N-terminus (H6YUH1) or C-terminus (YUH1H6) and purified by an immobilized metal affinity chromatography with high purity. By using a fluorogenic substrate, Z-Arg-Leu-Arg-Gly-Gly-AMC, the deubiquitinating activities for H6YUH1 (1.

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