High-resolution crystal structure of the non-specific lipid-transfer protein from maize seedlings

AbstractBackground: The movement of lipids between membranes is aided by lipid-transfer proteins (LTPs). Some LTPs exhibit broad specificity, transferring many classes of lipids, and are termed non-specific LTPs (ns-LTPs). Despite their apparently similar mode of action, no sequence homology exists between mammalian and plant ns-LTPs and no three-dimensional structure has been reported for any plant ns-LTP.Results We have determined the crystal structure of ns-LTP from maize seedlings by multiple isomorphous replacement and refined the structure to 1.9 å resolution. The protein comprises a single compact domain with four α-helices and a long C-terminal region. The eight conserved cysteines form four disulfide bridges (assigned as Cys4–Cys52, Cys14–Cys29, Cys30–Cys75, and Cys50–Cys89) resolving the ambiguity that remained from the chemical determination of pairings in the homologous protein from castor bean. Two of the bonds, Cys4–Cys52 and Cys50–Cys89, differ from what would have been predicted from sequence alignment with soybean hydrophobic protein. The complex between maize ns-LTP and hexadecanoate (palmitate) has also been crystallized and its structure refined to 1.8 å resolution.Conclusion The fold of maize ns-LTP places it in a new category of all-α-type structure, first described for soybean hydrophobic protein. In the absence of a bound ligand, the protein has a tunnel-like hydrophobic cavity, which is large enough to accommodate a long fatty acyl chain. In the structure of the complex with palmitate, most of the acyl chain is buried inside this hydrophobic cavity

5′-Triphosphate-RNA-independent activation of RIG-I via RNA aptamer with enhanced antiviral activity

RIG-I is a cytosolic receptor for non-self RNA that mediates immune responses against viral infections through IFNα/β production. In an attempt to identify novel tools that modulate IFNα/β production, we used SELEX technology to screen RNA aptamers that specifically target RIG-I protein. Most of the selected RIG-I aptamers contained polyU motifs in the second half regions that played critical roles in the activation of RIG-I-mediated IFNβ production. Unlike other known ligands, RIG-I aptamer bound and activated RIG-I in a 5′-triphosphate-independent manner. The helicase and RD domain of RIG-I were used for aptamer binding, but intact RIG-I protein was required to exert aptamer-mediated signaling activation. Furthermore, replication of NDV, VSV and influenza virus in infected host cells was efficiently blocked by pre- or post-treatment with RIG-I aptamer. Based on these data, we propose that RIG-I aptamer has strong potential to be an antiviral agent that specifically boosts the RIG-I-dependent signaling cascade

Tunable colors of chiral liquid crystal displays

Abstract We report a method of the color variation in the reflective CLC displays depending on thermodynamically and the electric field switching. The reflective wavelength can be thermodynamically switched to reflect green from a cell initially reflecting a red color. Afterwards, the reflective wavelength can be electrically switched to reflect blue color. It is found that continuous decrease of the pitch is mainly originated from the dopant solubility below the critical temperature and stepwise decrease of the pitch is dominantly affected by the thermodynamic property above the critical temperature. The blue color change is a result of the compression to the helical pitches in planar layers in response to the applied voltage

Antiosteoporosis Activity of New Oriental Medicine Preparation (Kyungokgo Mixed with Water Extract of Hovenia dulcis

Protective effect of new oriental medicine (Kyungokgo mixed with water extract of Hovenia dulcis, KOGHD) was assessed on the bone loss induced mice by ovariectomy. In the in vivo experiments, antiosteoporosis effect of KOGHD was investigated using ovariectomized osteoporosis mice model. After 6 weeks of treatment, the mice were euthanized, and the effect of Kyungokgo (KOG) and KOGHD on body weight, spleen weigh, thymus weight, uterine weight, serum biochemical indicators, bone weight and length, immune cell population, bone morphometric parameters, and histological stains was observed. Our results showed that KOGHD prevented the deterioration of trabecular microarchitecture caused by ovariectomy, which were accompanied by the lower levels of bone turnover markers and immune cell population as evidenced by the inhibition of RANKL-mediated osteoclast differentiation without cytotoxic effect on bone marrow derived macrophages (BMMs). Therefore, these results suggest that the Hovenia dulcis (HD) supplementation in the KOG may also prevent and treat bone loss

Long-term impact of coronavirus disease 2019 pandemic on emergency department utilization in a metropolitan emergency department in Korea

Purpose As coronavirus disease 2019 pandemic has been prolonged, it became crucial to analyze the long-term impact of the pandemic on emergency department (ED) utilization for efficient use of emergency medicine resources. Methods We reviewed the data of children (≤ 18 years) who visited the ED in Daejeon, Korea, from February 2019 through January 2021. This period was dichotomized by February 2020 into the reference and pandemic periods. The latter period was further divided into the early (February-August 2020) and late pandemic periods. Between the reference and pandemic periods, and between the early and late pandemic periods, we respectively compared proportions of children in all patients (including adults), age groups, high acuity (the Korean Triage and Acuity Scale 1-2), diagnostic codes, visits via ambulances, ED length of stay, and ED disposition. Results Compared to the reference and early pandemic periods, the pandemic and late pandemic periods respectively showed changes as follows: proportion of children in all patients (from 29.8% to 19.0% and from 19.8% to 18.1%; all Ps < 0.001), children younger than 5 years (from 56.7% to 49.9% and from 52.1% to 47.4%; all Ps < 0.001), high acuity (from 12.0% to 7.8% [P < 0.001] and from 8.8% to 6.7% [P = 0.004]), “Injury, poisoning and certain other consequences of external causes (S00-T98; from 30.0% to 49.0% and from 48.3% to 49.8%),” and “Diseases of the respiratory system (J00-J99; from 29.6% to 10.3% and from 12.8% to 7.5%).” Increases in the visits via ambulances, ED length of stay, children undergoing intensive care unit hospitalization or death were noted only in comparison between the reference and pandemic periods. Conclusion A long-term impact of the pandemic on ED use may be a decrease in the proportion of young or ill children