Significance Plants can sense loss of water caused by drought and stimulate internal mechanisms for protecting cells from damage with the aid stress hormone abscisic acid (ABA). Analysis a mutant basal land plant, moss Physcomitrella patens , revealed that an impairment protooncogene Raf-like protein kinase, designated “ARK” (for “ABA abiotic stress-responsive kinase”), causes both ABA sensitivity osmotic tolerance. We show evidence ARK has role in integrating signals upstream sucrose...

The right combination: A series of aromatic, heteroaromatic, aliphatic, and α,β-unsaturated aldehydes can be converted into the desired silylated cyanohydrins by reaction with (CH3)3SiCN a catalyst system consisting combination chiral ruthenium complex Li2CO3 (see scheme). is highly enantioselective affords R products up to 98 % ee within 24 h at substrate-to-catalyst ratio 10 000:1. Supporting information for this article available on WWW under...

Abstract Synthetic insulin analogues with a long lifetime are current drug targets for the therapy of diabetic patients. The replacement interchain disulfide diselenide bridge, which is more resistant to reduction and internal bond rotation, can enhance in presence insulin‐degrading enzyme (IDE) without impairing hormonal function. [C7U A ,C7U B ] variant bovine pancreatic (BPIns) was successfully prepared by using two selenocysteine peptides (i.e., C7U A‐ B‐chains, respectively). In buffer...

Abstract Electrochemical microreactors, which have electrodes integrated into the flow path, can afford rapid and efficient electrochemical reactions without redox reagents due to intrinsic properties of short diffusion distances. Taking advantage Kolbe electrolysis di‐ trifluoroacetic acid in presence various electron‐deficient alkenes was performed under constant current at continuous room temperature. As a result, trifluoromethylated compounds were effectively produced either equal or...

Pep talk: Selenoglutathione (GSeH) and other peptides containing selenocysteine with an amino acid sequence of the glutathione peroxidase (GPx) active site are obtained in oxidized form by solid-phase peptide synthesis. Their GPx activity against hydrogen peroxide (see picture) reveals that GSeH has effective antioxidant addition to biological function a analogue.

Since the finding that selenium is an essential micronutrient for our life as well discovery of selenocysteine (Sec) twenty-first proteinogenic amino acid expressed by using information encoded in genes, research fields chemical biology and biological chemistry have been expanding to a new paradigm where plays important roles. A number selenoenzymes, which utilize atom active center, already characterized, their functions identified. However, underlying behind molecular mechanisms still not...

To elucidate the effects of ring structure and a substituent on glutathione peroxidase- (GPx-) like antioxidant activities aliphatic selenides, series water-soluble cyclic selenides with variable size polar functional groups were synthesized, their evaluated by NADPH-coupled assay using H2O2 (GSH) in water also NMR spectroscopy dithiothreitol (DTT(red)) methanol. Strong correlations found among GPx-like activity water, second-order rate constants for oxidation HOMO energy levels calculated...

Selenoglutathione (GSeH) is a selenium analogue of naturally abundant glutathione (GSH). In this study, water-soluble small tripeptide was synthesized in high yield (up to 98%) as an oxidized diselenide form, i.e., GSeSeG (1), by liquid-phase peptide synthesis (LPPS). Obtained 1 applied the investigation peroxidase (GPx)-like catalytic cycle. The important intermediates, GSe– and GSeSG, besides GSeO2H were characterized 77Se NMR spectroscopy. Thiol exchange GSeSG with various thiols, such...

Compounds harboring high acidity and oxidizability of thiol groups permit tuning the redox equilibrium constants CxxC sites PDI family enzymes thus can be used to promote oxidative folding increase native protein productions by minimal loading as compared glutathione.

Abstract The protein disulfide isomerase (PDI) family, found in the endoplasmic reticulum (ER) of eukaryotic cell, catalyzes formation and cleavage bonds thereby helps folding. A decrease PDI activity under ER stress conditions leads to misfolding, which is responsible for progression various human diseases, such as Alzheimer's, Parkinson's, diabetes mellitus, atherosclerosis. Here we report that water‐soluble cyclic diselenides mimic multifunctional family by facilitating oxidative folding,...

Abstract At the redox‐active center of thioredoxin reductase (TrxR), a selenenyl sulfide (Se−S) bond is formed between Cys497 and Sec498, which activated into thiolselenolate state ([SH,Se − ]) by reacting with nearby dithiol motif ([SH Cys59 ,SH Cys64 present in other subunit. This process achieved through two reversible steps: an attack cysteinyl thiol at Se atom Se−S subsequent remaining S generated mixed intermediate. However, it not clear how kinetically unfavorable second step...

Effective chemical catalysts can artificially control intracellular metabolism. However, in conventional catalytic chemistry, activity and cytotoxicity have a trade-off relationship; thus, driving living cells remains challenging. To overcome this critical issue at the interface between chemistry biology, we developed cell-driven allosteric that exert specific times. The synthesized redox up- downregulated their foldase- antioxidase-like activities response to varying Ca2+ concentrations,...

Abstract To elucidate the reaction mechanism of disulfide (SS) bond formation a polypeptide molecule with water‐soluble selenoxide reagent, trans ‐3,4‐dihydroxyselenolane oxide (DHS ox ), short‐term oxidation experiments were carried out for reduced state (R) recombinant hirudin CX‐397 variant at pH 7.0 and 25 °C. In reaction, R was oxidized sequentially to one‐SS, two‐SS, three‐SS intermediate ensembles within 1 min. The kinetic analysis revealed that three second‐order rate constants SS...

Electroreductive deprotection of the isonicotinyloxycarbonyl (iNoc) group from hydroxy, thiol, and amino groups was carried out in an electrochemical microreactor. The small distance platinum electrodes microreactor enables a rapid redox reaction without added electrolytes. As result, O- S-iNoc aromatic substrates achieved short times (<2 min), while N-iNoc nonaromatic did not react under same conditions. This method site-selective or removal moieties.

The utilization of red and blue light-emitting diode (LED) lights for cultivating leafy vegetables in closed plant factories has increased recent years. This study examined the growth biosynthesis functional compounds twelve Spinacia accessions, including cultivars wild relatives, under irradiation fluorescent light three different red-to-blue LED combinations (red:blue = 1:1, 1:3, 3:1). Results showed that, except Japanese cultivars, fresh weight most spinach accessions when comprised...

Kombinierter Katalysator: Zahlreiche (hetero)aromatische, aliphatische und α,β-ungesättigte Aldehyde können in silylierte Cyanohydrine umgewandelt werden, wenn man das Reagens (CH3)3SiCN mit einem Katalysatorsystem aus chiralen Rutheniumkomplex Li2CO3 kombiniert (siehe Schema). Bei Substrat/Katalysator-Verhältnis von 10 000:1 liefern diese Reaktionen binnen 24 h die R-Produkte bis zu 98 % ee. Supporting information for this article is available on the WWW under...

Abstract Until recently the total synthesis of insulin, with its characteristic heterodimeric structure crosslinked by two interchain and one intrachain disulfide (SS) bridge, remained largely an unsolved challenge. By optimizing directed crosslinking chains, applying biomimetic monocomponent proinsulin approaches, efficient insulin syntheses have been realized. Here we report optimization characterisation alternative strategy, oxidative native chain assembly. In this method unprotected A-...

Coupling of thiol and urea-type –NHC(X)NH₂ (X = O or NH) groups is effective in promoting oxidative protein folding.

Intermolecular aromatic C(sp2)-H amination promoted by neutral rhodium nitrenoids has been developed. The reactions proceeded with various oxygen-substituted arenes (1.5 equiv.) in a chemo- and regioselective manner. took place at the para position of oxygen substituent presence benzylic C(sp3)-H bonds and/or α to ethereal oxygen.

We report the first example of a synthetic thiol-based compound that promotes oxidative protein folding upon 1-equivalent loading to disulfide bonds in client afford native form over 70% yield. N-Methylation is central post-translational processing proteins vivo for regulating functions including chaperone activities. Despite universally observed biochemical reactions nature, N-methylation has hardly been utilized design, functionalization, and switching bioregulatory agents, particularly...