Pseudo-Isolated α-Helix Platform for the Recognition of Deep and Narrow Targets.

Although interest in stabilized α-helical peptides as next-generation therapeutics for modulating biomolecular interfaces is increasing, peptides have limited functionality and stability due to their small size. In comparison, α-helical ligands based on proteins can make steric clash with targets due to their large size. Here, we report the design of a monomeric pseudo-isolated α-helix (mPIH) system in which proteins behave as if they are peptides. The designed proteins contain α-helix ligands that do not require any covalent chemical modification, do not have frayed ends, and importantly can make sterically favorable interactions similar to isolated peptides. An optimal mPIH showed a more than 100-fold increase in target selectivity, which might be related to the advantages in conformational selection due to the absence of frayed ends. The α-helical ligand in the mPIH displayed high thermal stability well above human body temperature and showed reversible and rapid folding/unfolding transitions. Thus, mPIH can become a promising protein-based platform for developing stabilized α-helix pharmaceuticals.

Chrysin Induces Apoptosis via the MAPK Pathway and Regulates ERK/mTOR-Mediated Autophagy in MC-3 Cells.

Chrysin is a flavonoid found abundantly in substances, such as honey and phytochemicals, and is known to exhibit anticancer effects against various cancer cells. Nevertheless, the anticancer effect of chrysin against oral cancer has not yet been verified. Furthermore, the mechanism underlying autophagy is yet to be clearly elucidated. Thus, this study investigated chrysin-mediated apoptosis and autophagy in human mucoepidermoid carcinoma (MC-3) cells. The change in MC-3 cell viability was examined using a 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide cell viability assay, as well as 40,6-diamidino-2-phenylindole, annexin V, and propidium iodide staining. Western blotting was used to analyze the proteins related to apoptosis and the mitogen-activated protein kinase (MAPK) pathway. In addition, the presence or absence of autophagy and changes in the expression of related proteins were investigated using acridine orange staining and Western blot. The results suggested that chrysin induced apoptosis and autophagy in MC-3 oral cancer cells via the MAPK/extracellular signal-regulated kinase pathway. Moreover, the induced autophagy exerted a cytoprotective effect against apoptosis. Thus, the further reduced cell viability due to autophagy as well as apoptosis induction highlight therapeutic potential of chrysin for oral cancer.

Dietary Taurine Intake and Its Food Sources in Korean Young Adults Using 2015 Korea National Health and Nutrition Examination Survey Data.

This study aimed to estimate the dietary taurine intake and its food sources in Korean's aged between 19 and 29 years. The study included 619 participants (292 males and 327 females) who had provided data via a 24-h recall method to the 2015 Korea National Health and Nutrition Examination Survey (KNHANES). Dietary taurine intake and the sources of dietary taurine were estimated by using CAN-Pro 4.0 software. Statistical analysis was performed by using SPSS 20.0. Average height and weight of the subjects was 174 cm and 73.5 kg in males and 161 cm and 56.4 kg in females, respectively. The prevalence of obesity in males was significantly higher compared to females (p < 0.001). Overall, the nutrient intakes of subjects were higher than the dietary reference intakes for Korean's (KDRIs). In particular, phosphorus and sodium intakes of males and females were higher, whereas, potassium and calcium intakes of males and females were lower than the KDRIs. The average intake of taurine 327.3 mg by males was significantly higher compared to 245.1 mg by females (p < 0.05). With regard to dietary taurine intake from the main food groups, meat (p < 0.001), vegetable (p < 0.001), beverages and alcohol (p < 0.05), and cereal (p < 0.001), in males was significantly higher compared to females. This study showed that 19-29 years old Korean young adults had a high intake of taurine due to high intake of protein. However, since high intake of meat can lead to chronic disease, it is necessary to provide nutrition education to increase the intake of fishes and shellfishes as a taurine source food.

Effects of Dietary Taurine Supplementation on Blood and Urine Taurine Concentrations in the Elderly Women with Dementia.

The purpose of this research is to investigate the effects of dietary taurine supplementation on blood and urine taurine concentrations of the elderly women with dementia. Subjects were 31 female elderly with dementia hospitalized in a geriatric hospital. They were divided randomly into control group and dietary taurine supplemented group. Basically, same meals were served to both groups. Scorched rice water without taurine were served to control group. Scorched rice water containing 3 g of taurine were reserved to taurine group with lunch similarly. Food ingredients containing high concentration of taurine were eliminated from the meal menu. Blood and urine samples were obtained from each subject at the beginning of study, after 2 week and 4 weeks in the morning fasting state. Taurine concentrations in serum and urine were measured as taurine-fluorescamine derivatives using high performance liquid chromatography (HPLC). Data were analyzed using SPSS 20.0. The average taurine concentrations in serum and urine of subjects were 89.2 ± 9.5 µM and 876.7 ± 97.1 µM at the beginning. After 4 weeks, the taurine concentrations in serum and urine of dietary taurine supplemented group were 218.0 ± 15.6 µM and 6502.6 ± 380.6 µM, which were significantly higher compared to control group. Dietary taurine supplemented group showed positive changes in the score on language and execute performance. So taurine supplementation can provide beneficial effects to the elderly and the elderly with dementia.

Food Preference of the Elderly for the Development of Taurine-Containing Elderly-Friendly Foods.

The purpose of this study was to investigate food preference of the elderly for the development of taurine-containing elderly-friendly foods (TEF). The subjects in this study were 278 elderly people who were over 65 years old. All data were collected by face to face interview. Statistical analysis was performed by using SPSS 20.0 for Windows. The 'low-salt diet', 'nutritional enriched diet', and 'swallow able diet' were diets that all subjects preferred. All subjects preferred a diet to be sold as three items in separate packaging, as a semi-cooked type. The food types and cooking methods that showed high preference and had a high intention to purchase were cooked rice, porridges, soups and stews, meat side dishes, fish side dishes, kimchi, and vegetable dishes and steaming Among the taurine-containing foods, whip-arm octopus, manila clam, dried anchovy, flatfish, pollack, laver, green laver, sea tangle, seaweed, cod, croaker, and cutlassfish were the preferred foods of most subjects. Elderly females preferred significantly more squid, octopus, eel, mudfish, and sea cucumber than that of elderly males (p < 0.05). Elderly males preferred and consumed significantly more taurine-supplement than did elderly females (p < 0.05). These results will be used as baseline data for development of a customized TEF for Korean elderly.

Taurine-Related Nutritional Knowledge Has a Positive Effect on Intake of Taurine and Cognitive Function in the Elderly.

The purpose of this study was to investigate the correlations among taurine-related nutritional knowledge (TNK), taurine intake frequency (TIF), and cognitive function (CF) in Korean elderly. Subjects of this cross-sectional study were 278 elderly persons in Korea without dementia (men 76, women 202). The subjects were divided into two groups: a group with a lower than average TNK score (LAG) and a group with a higher than average TNK score (HAG). Data were obtained via questionnaires and 1: 1 interviews. Correlation analysis available in SPSS 20.0 was used to analyze associations among the three factors. Average TNK score of all subjects was 4 out of 10 points, while that of the LAG (1.9 points) was significantly lower than that of the HAG (6.6 points) (p < 0.001). Average TIF score in the HAG (195.3 points) was significantly higher than that of the LAG (180.8 points) (p < 0.001). Compared to the LAG, the HAG members more frequently consumed foods such as webfoot octopus, whelk, dried anchovy, dried shrimp, mackerel, anglerfish, skate, short-necked clam, shrimp, and dried squid (p < 0.01). There was no significant difference in CF scores between the LAG and HAG. There was positive correlation between TNK and TIF scores in all the subjects (p < 0.01). There was no significant difference, but there was a tendency for a positive correlation, between TNK and CF scores (p = 0.072). These results suggest that nutritional education of the elderly about taurine is needed, and it is strongly recommended that the elderly frequently consume taurine-containing foods and supplements to prevent dementia.

Consumption Patterns and Importance-Performance Analysis of Home Meal Replacements by Level of Taurine-Related Nutritional Knowledge in Korean Adults.

The purpose of this study was to investigate consumption patterns and perform Importance-Performance Analysis (IPA) of selective attributes of Home Meal Replacement (HMR) products according to taurine-related nutritional knowledge levels in Koreans aged 40-64 years as a basis for developing additional HMR products. The study included 793 adults (297 males and 496 females) who had experience in consuming HMR products and who lived in Seoul and its metropolitan areas, Korea. Data were collected using self-administered questionnaires. Statistical analysis was performed by using the SPSS 18.0 program. The subjects were classified into a high-level group (HG, 467 adults) and low-level group (LG, 326 adults) based on their taurine-related nutritional knowledge scores. Analysis of HMR consumption patterns showed that the frequency of HMR consumption in the HG was one to two times a month in 41.1% of the subjects and once every 3-4 months in 22.7% of the subjects, whereas, in the LG, it was one to two times a month in 39.3% of the subjects and four to six times a month in 24.5% of the subjects. With regarding to the reasons for purchasing HMR products, there was no significant difference between HG and LG (p = 0.089). The IPA analysis of HMR selective attributes included factor analysis of 14 selective attributes that were divided into three factors: 'convenience and taste', 'reliability and health', and 'brand and awareness'. The average importance scores of the first (p < 0.01), second (p < 0.001), and third (p < 0.01) factors in the HG were significantly higher than those in the LG. In addition, the average satisfaction with the first factor (p < 0.01) in the HG was significantly higher than that in the LG. Based on the IPA results, the selective attributes with low satisfaction and high importance were price, origin, food additives, and nutrient content in both the HG and LG. In the second IPA quadrant was safety, but only in the LG. Multiple regression analysis revealed that the importance of the reliability and health factor and the satisfaction with the convenience and taste factor were positively influenced by the subject's taurine-related nutritional knowledge score. These results suggest that reliability and safety of HMR products need to be improved to meet the expectations of Korean consumers aged 40 years and older with a high level of taurine-related nutritional knowledge. Therefore, there is a need to produce HMR products that use safe and reliable food ingredients.

Demands for Development of Taurine-Containing Home Meal Replacement for Prevention of Dementia According to Age.

It has been reported that taurine intake in the past may have a positive effect on present cognitive function in the elderly. The purpose of this cross-sectional study was to investigate the need to develop an elderly-friendly home meal replacement (EF-HMR) containing taurine for the prevention of dementia in Korean adults aged 40-84 years. Study subjects included 481 adults 40-49 years group, 319 adults 50-64 years group, and 181 elderly group (65-84 years old) residing in Seoul and its metropolitan area, Korea. Data were collected from adults aged 40-64 years by self-administered questionnaires and from elderly through face-to-face interviews. Statistical analysis was performed using SPSS 18.0. The level of need for EF-HMR was significantly higher in 40-49 years and 50-64 years groups compared to the elderly group (p < 0.001). With regard to the preferred EF-HMR taste, the needs for less salty (p < 0.01) and less sweet (p < 0.001) foods were significantly higher in 40-49 years group compared to the elderly group. The main factors of consideration in the development of EF-HMR were nutrition, taste, and freshness. The level of need for EF-HMR containing taurine was significantly lower in those 40-49 years and 50-64 years groups compared to the elderly group (p < 0.01). If an EF-HMR containing taurine for prevention of dementia was developed, willingness to buy such a food was significantly higher in the elderly group than in those 40-49 years and 50-64 years groups (p < 0.01). Regarding cooked EF-HMR containing taurine, semi-prepared and ready-made meals were preferred in 71.1% and 25.4% in 40-49 years group, 69.6% and 22.6% in 50-64 years group, and 47.0% and 33.7% in the elderly group, respectively (p < 0.001). EF-HMR containing taurine sales unit sizes containing 3 servings or 1 serving was preferred by 37.2% and 26.3% of all subjects. The preferred places to purchase EF-HMR (in descending order of super-supermarket (mart), supermarket, and convenience store) were the same among the age groups. Therefore, it is necessary to understand the diversity present in the needs and purchasing characteristics of adults involved purchasing EF-HMR containing taurine, and there is a need to develop age-specific customized products for the elderly and for Korean adults 40-64 years old.

Cyclic Peptide-Decorated Self-Assembled Nanohybrids for Selective Recognition and Detection of Multivalent RNAs.

Although there has been substantial advancement in the development of nanostructures, the development of self-assembled nanostructures that can selectively recognize multivalent targets has been very difficult. Here we show the proof of concept that topology-controlled peptide nanoassemblies can selectively recognize and detect a multivalent RNA target. We compared the differential behaviors of peptides in a linear or cyclic topology in terms of peptide-gold nanoparticle hybrid nanostructure formation, conformational stabilization, monovalent and multivalent RNA binding in vitro, and multivalent RNA recognition in live cells. When the topology-dependent selectivity amplification of the cyclic peptide hybrids is combined with the noninvasive nature of dark-field microscopy, the cellular localization of the viral Rev response element (RRE) RNA can be monitored in situ. Because intracellular interactions are often mediated by overlapping binding partners with weak affinity, the topology-controlled peptide assemblies can provide a versatile means to convert weak ligands into multivalent ligands with high affinity and selectivity.

Macromolecular sensing of RNAs by exploiting conformational changes in supramolecular nanostructures.

Here, we report on a ratiometric fluorescence biosensor based on self-assembled peptide nanostructures (SPN), which can respond to conformational changes induced by RNA ligand binding. The design of the SPN biosensor was inspired by the conformational stabilization and multimerization behaviors of the HIV-1 Rev protein induced by cooperative protein-protein and protein-RNA interactions. Because conformation-sensitive SPN biosensors can orchestrate binding and signal transduction events, they can be developed as highly sophisticated and smart nanomaterials for biosensing.