Crystal structure of the Ate1 arginyl-tRNA-protein transferase and arginylation of N-degron substrates.

N-degron pathways are proteolytic systems that target proteins bearing N-terminal (Nt) degradation signals (degrons) called N-degrons. Nt-Arg of a protein is among Nt-residues that can be recognized as destabilizing ones by the Arg/N-degron pathway. A proteolytic cleavage of a protein can generate Arg at the N terminus of a resulting C-terminal (Ct) fragment either directly or after Nt-arginylation of that Ct-fragment by the Ate1 arginyl-tRNA-protein transferase (R-transferase), which uses Arg-tRNA as a cosubstrate.

Antimicrobial Resistance and Molecular Characterization of Extended-Spectrum β-Lactamase-Producing Isolated from Ducks in South Korea.

Ducks are potential carriers of pathogenic bacteria, which are capable of transmitting zoonotic diseases to humans. The global spread of carrying extended-spectrum β-lactamase (ESBL) genes is a public health concern. This study investigated the prevalence of antimicrobial resistance in isolated from ducks in Korea and described the molecular characteristics of the ESBLs they produced.

Detection of oxazolidinone and phenicol resistant enterococcal isolates from duck feces and carcasses.

The heavy use or abuse of antimicrobials in food animals has caused an increase in antimicrobial resistance in enterococci of animal origin, which could get transmitted to those of human origin via the food chain. Since duck meat consumption has been on the rise in Korea, we conducted this study to provide information about the antimicrobial resistance of the enterococci obtained from healthy ducks and their carcasses. A total of 82 Enterococcus faecium and 174 E.

ACCORD: an assessment tool to determine the orientation of homodimeric coiled-coils.

The coiled-coil (CC) domain is a very important structural unit of proteins that plays critical roles in various biological functions. The major oligomeric state of CCs is a dimer, which can be either parallel or antiparallel. The orientation of each α-helix in a CC domain is critical for the molecular function of CC-containing proteins, but cannot be determined easily by sequence-based prediction.

Structural basis for dual specificity of yeast N-terminal amidase in the N-end rule pathway.

The first step of the hierarchically organized Arg/N-end rule pathway of protein degradation is deamidation of the N-terminal glutamine and asparagine residues of substrate proteins to glutamate and aspartate, respectively. These reactions are catalyzed by the N-terminal amidase (Nt-amidase) Nta1 in fungi such as Saccharomyces cerevisiae, and by the glutamine-specific Ntaq1 and asparagine-specific Ntan1 Nt-amidases in mammals. To investigate the dual specificity of yeast Nta1 (yNta1) and the importance of second-position residues in Asn/Gln-bearing N-terminal degradation signals (N-degrons), we determined crystal structures of yNta1 in the apo state and in complex with various N-degron peptides.

Photoprotective properties of 20(S)-protopanaxatriol, an aglycone of ginseng saponins: Protection from ultraviolet-B radiation-induced oxidative stress in human epidermal keratinocytes.

Ginsenosides are responsible for diverse pharmacological properties ascribed to ginseng, a plant used in traditional medicine. Ginsenosides are classified into three categories: Protopanaxadiol, protopanaxatriol (PPT) and oleanolic acid. As an aglycone of PPT-type ginsenosides, PPT exists in two stereoisomeric forms, 20(S)-PPT and 20(R)‑PPT.

Protective properties of ginsenoside Rb3 against UV-B radiation-induced oxidative stress in HaCaT keratinocytes.

This work aimed to evaluate the skin anti-photoaging properties of ginsenoside Rb3 (Rb3), one of the main protopanaxdiol-type ginsenosides from ginseng, in HaCaT keratinocytes. The skin anti-photoaging activity was assessed by analyzing the levels of reactive oxygen species (ROS), pro-matrix metalloproteinase-2 (proMMP-2), pro-matrix metalloproteinase-9 (proMMP-9), total glutathione (GSH), and superoxide dismutase (SOD) activity as well as cell viability in HaCaT keratinocytes under UV-B irradiation. When HaCaT keratinocytes were exposed to Rb3 prior to UV-B irradiation, Rb3 exhibited suppressive activities on UV-B-induced ROS, proMMP-2, and proMMP-9 enhancements.

Protective properties of ginsenoside Rb1 against UV-B radiation-induced oxidative stress in human dermal keratinocytes.

Ginsenosides, also known as ginseng saponins, are responsible for most pharmacological effect of ginseng. Ginsenoside Rb1 (Rb1) exerts a variety of pharmacological properties, including anti-inflammatory, antistress, anti-aging and anti-neurodegenerative activities. The aim of the present work was to assess the skin anti-photoaging properties of Rb1 in human dermal keratinocyte HaCaT cells.

Ginsenoside Rb2 Attenuates UV-B Radiation-Induced Reactive Oxygen Species and Matrix Metalloproteinase-2 through Upregulation of Antioxidant Components in Human Dermal Fibroblasts.

Aims: The antiphotoaging activities of ginsenoside Rb2 on the skin, one of the predominant protopanaxadiol-type ginsenosides, were evaluated in cultured human dermal fibroblasts.

Methods: The antiphotoaging activity was examined by analyzing the levels of reactive oxygen species (ROS), matrix metalloproteinase-2 (MMP-2), total glutathione (GSH) and superoxide dismutase (SOD) activity as well as cell viability for fibroblasts under UV-B irradiation.

Results: When cultured fibroblasts were exposed to Rb2 prior to UV-B irradiation, Rb2 displayed suppressive activities on UV-B-induced ROS elevation and MMP-2 on both activity and protein levels, while it exhibited an enhancing activity on total GSH level and SOD activity diminished by UV-B irradiation.

Suppressive properties of ginsenoside Rb2, a protopanaxadiol-type ginseng saponin, on reactive oxygen species and matrix metalloproteinase-2 in UV-B-irradiated human dermal keratinocytes.

Ginsenosides, also known as ginseng saponins, are the principal bioactive ingredients of ginseng, which are responsible for its diverse pharmacological activities. The present work aimed to assess skin anti-photoaging properties of ginsenoside Rb2 (Rb2), one of the predominant protopanaxadiol-type ginsenosides, in human epidermal keratinocyte HaCaT cells under UV-B irradiation. When the cultured keratinocytes were subjected to Rb2 prior to UV-B irradiation, Rb2 displayed suppressive activities on UV-B-induced reactive oxygen species elevation and matrix metalloproteinase-2 expression and secretion.

Stereoselective suppressive effects of protopanaxadiol epimers on UV-B-induced reactive oxygen species and matrix metalloproteinase-2 in human dermal keratinocytes.

This study aimed to assess the skin-related anti-photoaging activities of the 2 epimeric forms of protopanaxadiol (PPD), 20(S)-PPD and 20(R)-PPD, in cultured human keratinocytes (HaCaT cells). The anti-photoaging activity was evaluated by analyzing the levels of reactive oxygen species (ROS) and matrix metalloproteinases (MMPs), as well as cell viability for HaCaT cells under UV-B irradiation. The activities for MMP-2 and -1 in conditioned medium were determined using gelatin zymography, and MMP-2 protein in the conditioned medium was detected using Western blot analysis.

Skin anti-photoaging properties of ginsenoside Rh2 epimers in UV-B-irradiated human keratinocyte cells.

Ginseng, one of the most widely used herbal medicines, has a wide range of therapeutic and pharmacological applications. Ginsenosides are the major bioactive ingredients of ginseng, which are responsible for various pharmacological activities of ginseng. Ginsenoside Rh2, known as an antitumour ginsenoside, exists as two different stereoisomeric forms, 20(S)-ginsenoside Rh2 [20(S)-Rh2] and 20(R)-ginsenoside Rh2 [20(R)-Rh2].