Caffeine is chemically stable and not readily oxidized under normal physiological conditions but also has antioxidant effects, although the underlying molecular mechanism is not well understood. Superoxide dismutase (SOD) 2 is a manganesecontaining enzyme located in mitochondria that protects cells against oxidative stress by scavenging reactive oxygen species (ROS). SOD2 activity is inhibited through acetylation under conditions of stress such as exposure to ultraviolet (UV) radiation. Sirtuin 3 (SIRT3) is the major mitochondrial nicotinamide adenine dinucleotide (NAD +)-dependent deacetylase, which deacetylates two critical lysine residues (lysine 68 and lysine 122) on SOD2 and promotes its antioxidative activity. In this study, we investigated whether the antioxidant effect of caffeine involves modulation of SOD2 by SIRT3 using in vitro and in vivo models. The results show that caffeine interacts with SIRT3 and promotes direct binding of SIRT3 with its substrate, thereby enhancing its enzymatic activity. Mechanistically, caffeine bound to SIRT3 with high affinity (K D = 6.858 × 10 −7 M); the binding affinity between SIRT3 and its substrate acetylated p53 was also 9.03 (without NAD +) or 6.87 (with NAD +) times higher in the presence of caffeine. Caffeine effectively protected skin cells from UV irradiation-induced oxidative stress. More importantly, caffeine enhanced SIRT3 activity and reduced SOD2 acetylation, thereby leading to increased SOD2 activity, which could be reversed by treatment with the SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP) in vitro and in vivo. Taken together, our results show that caffeine targets SIRT3 to enhance SOD2 activity and protect skin cells from UV irradiation-induced oxidative stress. Thus, caffeine, as a small-molecule SIRT3 activator, could be a potential agent to protect human skin against UV radiation.

We study the support recovery problem for a high-dimensional signal observed with additive noise. With suitable parametrization of the signal sparsity and magnitude of its non-zero components, we characterize a phase-transition phenomenon akin to the signal detection problem studied by Ingster in 1998. Specifically, if the signal magnitude is above the so-called strong classification boundary, we show that several classes of well-known procedures achieve asymptotically perfect support recovery as the dimension goes to infinity. This is so, for a very broad class of error distributions with light, rapidly varying tails which may have arbitrary dependence. Conversely, if the signal is below the boundary, then for a very broad class of error dependence structures, no thresholding estimators (including ones with data-dependent thresholds) can achieve perfect support recovery. The proofs of these results exploit a certain concentration of maxima phenomenon known as relative stability. We provide a complete characterization of the relative stability phenomenon for Gaussian triangular arrays in terms of their correlation structure. The proof uses classic Sudakov-Fernique and Slepian lemma arguments along with a curious application of Ramsey's coloring theorem.We note that our study of the strong classification boundary is in a finer, point-wise, rather than minimax, sense. We also establish results on the finite-sample Bayes optimality and sub-optimality of thresholding procedures. Consequently, we obtain a minimax-type characterization of the strong classification boundary for errors with log-concave densities.

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A carrageenan-degrading marine Cellulophaga lytica strain N5-2 was isolated from the sediment of carrageenan production base. A κ-carrageenase (EC 3.2.1.83) with high activity was purified to electrophoretic homogeneity from the culture supernatant by a procedure of ammonium sulfate precipitation, dialyzing and gel filtration on SephadexG-200 and SephadexG-75. The purified enzyme was verified as a single protein on SDS-PAGE, and whose molecular weight was 40.8 kDa. The κ-carrageenase yielded a high activity of 1170 U/mg protein. For κ-carrageenase activity, the optimum temperature and pH were 35 °C and pH 7.0, respectively. The enzyme was stable at 40 °C for at least 2.5 h. The enzyme against κ-carrageenan gave a Km value of 1.647 mg/mL and a Vmax value of 8.7 μmol/min/mg when the reaction was carried out at 35 °C and pH 7.0. The degradation products of the κ-carrageenase were analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC), electrospray ionization time-of-flight mass spectroscopy (ESI-TOF-MS) and 13C-NMR spectroscopy, and the results indicated that the enzyme was specific of the β-1,4 linkage and hydrolyzed κ-carrageenan into κ-neocarraoctaose-sulfate and κ-neocarrahexaose-sulfate first, and then broke κ-neocarraoctaose-sulfate into κ-neocarrabiose-sulfate and κ-neocarrahexaose-sulfate.

Background and objectives: Near-isogenic lines (NILs) of three Chinese winter wheat varieties were used to explore quality differences between subunits 5 + 10 and 2 + 12. Protein content, gluten quality, rheological properties, and bread-making quality in the NILs possessing subunits 5 + 10 and 2 + 12 were assessed and compared. Findings: All measured parameters except protein content significantly changed when subunits 2 + 12 were replaced by subunits 5 + 10. The incorporation of subunits 5 + 10, in the absence of subunits 2 + 12, increased dramatically dough strength, but the extensibility was slightly decreased. The improved functionality of subunits 5 + 10 was only pronounced in the recipient cultivar (Xiaoyan 22) which had weak gluten strength but better extensibility, whereas, the inferior overall quality was obtained in the recipient cultivars (Xinong 2208 and Xinong 1718) carrying medium-to-strong gluten strength and poor extensibility. Conclusions: The functionality of subunits 5 + 10 was well expressed in the recipient cultivars with weak gluten strength and better extensibility. Significance and novelty: The findings expanded our knowledge on the functionality of subunits 5 + 10 on different genetic backgrounds with gradient elasticityto-extensibility ratio. The transformed lines with extremely strong gluten strength and reduced extensibility could be used as parents in wheat quality breeding and their flour would be suitable for blending with flour of the lower grade. K E Y W O R D Sbread making, common wheat, HMW-GS, near-isogenic line, quality property *These authors contributed equally to this work.How to cite this article: Wang X, Zhang Y, Zhang B, et al. Comparison of quality properties between high-molecular-weight glutenin subunits 5 + 10 and 2 + 12 near-isogenic lines under three common wheat genetic backgrounds. Cereal Chem. 2018;95:575-583. https://doi.

A concise protocol for the synthesis of (E)-alkenylferrocene derivatives based on the palladium-catalyzed three-component reaction of ferrocenyl allenes, aryl iodides and active methylene compounds was developed. This transformation exemplifies a simple method for the efficient synthesis of various mono-or bisallyl-substituted alkenylferrocenes in good yields with excellent regio-and stereoselectivities.

Jasmonates (JAs) play a key role in the regulation of growth and the defense response to environmental stresses. JAs inhibit plant growth and promote defense response. However, their roles in desert halophyte in the response to salt stress remain poorly understood. The effects of the combination of methyl jasmonate (MeJA) and NaCl treatment (the "MeN" condition) on the growth regulation and

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