Enzyme-Mediated Kinetic Control of Fe3+-Tannic Acid Complexation for Interface Engineering.

Supramolecular self-assembly of Fe3+ and tannic acid (TA) has received great attention in the fields of materials science and interface engineering because of its exceptional surface coating properties. Although advances in coating strategies often suggest that kinetics in the generation of interface-active Fe3+-TA species is deeply involved in the film formation, there is no acceptable elucidation for the coating process. In this work, we developed the enzyme-mediated kinetic control of Fe2+ oxidation to Fe3+ in a Fe2+-TA complex in the iron-gall-ink-revisited coating method. Specifically, hydrogen peroxide, produced in the glucose oxidase (GOx)-catalyzed reaction of d-glucose, accelerated Fe2+ oxidation, and the optimized kinetics profoundly facilitated the film formation to be about 9 times thicker. We also proposed a perspective considering the coating process as nucleation and growth. From this viewpoint, the kinetics in the generation of interface-active Fe3+-TA species should be optimized because it determines whether the interface-active species forms a film on the substrate (i.e., heterogeneous nucleation and film growth) or flocculates in solution (i.e., homogeneous nucleation and particle growth). Moreover, GOx was concomitantly embedded into the Fe3+-TA films with sustained catalytic activities, and the GOx-mediated coating system was delightfully adapted to catalytic single-cell nanoencapsulation.

Development of the anti-cancer food scoring system 2.0: Validation and nutritional analyses of quantitative anti-cancer food scoring model.

BACKGROUND/OBJECTIVES: We have previously designed the anti-cancer food scoring model (ACFS) 1.0, an evidence-based quantitative tool analyzing the anti-cancer or carcinogenic potential of diets. Analysis was performed using simple quantitative indexes divided into 6 categories (S, A, B, C, D, and E). In this study, we applied this scoring model to wider recipes and evaluated its nutritional relevance. MATERIALS/METHODS: National or known regional databases were searched for recipes from 6 categories: Korean out-dining, Korean home-dining, Western, Chinese, Mediterranean, and vegetarian. These recipes were scored using the ACFS formula and the nutrition profiles were analyzed. RESULTS: Eighty-eight international recipes were analyzed. All S-graded recipes were from vegetarian or Mediterranean categories. The median code values of each category were B (Korean home-dining), C (Korean out-dining), B (Chinese), A (Mediterranean), S (vegetarian), and D (Western). The following profiles were correlated (P < 0.05) with ACFS grades in the univariate trend analysis: total calories, total fat, animal fat, animal protein, total protein, vitamin D, riboflavin, niacin, vitamin B12, pantothenic acid, sodium, animal iron, zinc, selenium, and cholesterol (negative trends), and carbohydrate rate, fiber, water-soluble fiber, vitamin K, vitamin C, and plant calcium (positive trends). Multivariate analysis revealed that animal fat, animal iron, and niacin (negative trends) and animal protein, fiber, and vitamin C (positive trends) were statistically significant. Pantothenic acid and sodium showed non-significant negative trends (P < 0.1), and vitamin B12 showed a non-significant positive trend. CONCLUSION: This study provided a nutritional basis and extended the utility of ACFS, which is a bridgehead for future cancer-preventive clinical trials using ACFS.

Piezo1 incorporates mechanical force signals into the genetic program that governs lymphatic valve development and maintenance.

The lymphatic system plays crucial roles in tissue homeostasis, lipid absorption, and immune cell trafficking. Although lymphatic valves ensure unidirectional lymph flows, the flow itself controls lymphatic valve formation. Here, we demonstrate that a mechanically activated ion channel Piezo1 senses oscillating shear stress (OSS) and incorporates the signal into the genetic program controlling lymphatic valve development and maintenance. Time-controlled deletion of Piezo1 using a pan-endothelial Cre driver (Cdh5[PAC]-CreERT2) or lymphatic-specific Cre driver (Prox1-CreERT2) equally inhibited lymphatic valve formation in newborn mice. Furthermore, Piezo1 deletion in adult lymphatics caused substantial lymphatic valve degeneration. Piezo1 knockdown in cultured lymphatic endothelial cells (LECs) largely abrogated the OSS-induced upregulation of the lymphatic valve signature genes. Conversely, ectopic Piezo1 overexpression upregulated the lymphatic valve genes in the absence of OSS. Remarkably, activation of Piezo1 using chemical agonist Yoda1 not only accelerated lymphatic valve formation in animals, but also triggered upregulation of some lymphatic valve genes in cultured LECs without exposure to OSS. In summary, our studies together demonstrate that Piezo1 is the force sensor in the mechanotransduction pathway controlling lymphatic valve development and maintenance, and Piezo1 activation is a potentially novel therapeutic strategy for congenital and surgery-associated lymphedema.

Characterization of truncated endo-ß-1,4-glucanases from a compost metagenomic library and their saccharification potentials.

A gene encoding an endo-ß-1,4-glucanase (Cel6H-f481) was cloned from a compost metagenomic library. The gene, cel6H-f481, was composed of 1446 bp to encode a fused protein of 481 amino acid residues (50,429 Da), i.e., 445 residues (Cel6H-445) from the metagenome, and 36 residues from the pUC19 vector at N-terminus. Cel6H-445 belonged to glycosyl hydrolase (GH) family 6 and showed 71% identity with Actinotalea fermentans endoglucanase with low coverage. Several active bands of truncated forms were observed by activity staining of the crude extract. Major truncated enzymes of 35 (Cel6H-p35) and 23 kDa (Cel6H-p23) were separated by HiTrap Q chromatography. The two enzymes had the same optimum temperature (50 °C) and pH (5.5), but Cel6H-p35 was more thermostable than Cel6H-p23 and other GH6 endoglucanases reported. Both enzymes efficiently hydrolyzed carboxymethyl-cellulose (CMC) and barley ß-glucan, but hardly hydrolyzed other substrates tested. The Vmax of Cel6H-p35 for CMC was 1.4 times greater than that of Cel6H-p23. The addition of the crude enzymes to a commercial enzyme set increased the saccharification of pretreated rice straw powder by up to 30.9%. These results suggest the N-terminal region of Cel6H-p35 contributes to thermostability and specific activity, and that the enzymes might be a useful additive for saccharification.