The extraction of phenolic compounds from olive leaves was optimized using three glycerol-based deep eutectic solvents (DESs) with lysine, proline, and arginine. A three-level Box–Behnken design used to examine the influence liquid/solid ratio, concentration DESs, temperature on yield process. second-order polynomial model for predicting polyphenol yield. optimal predicted conditions were extractions they provided highest total phenol yields glycerol–lysine exhibiting best performance....

The thermostability of manganese stabilizing protein photosystem II was examined by biochemical and spectroscopic techniques. Samples both native recombinant spinach incubated at 90 degreesC then cooled to 25 were capable rebinding to, reactivating, the O2-evolution activity membranes from which had been removed. Far-UV circular dichroism FT-IR spectroscopies used analyze structural consequences heating protein. data obtained these techniques show that causes a complete loss protein's...

The complementary use of single cell atomic mass spectrometry (MS) and ambient molecular MS allowed for the in-depth study arsenate uptake by Chlamydomonas reinhardtii cells effect this toxic metalloid species has on their lipid profile. Compared to conventional inductively coupled plasma (ICP–MS) analysis, in which case hundreds thousands are digested then analyzed, it is demonstrated that (SC) ICP–MS provides data potentially greater biological relevance. This includes arsenic distribution...

Seawater intrusion into near-shore aquifers is one of the main environmental problems that affect Mediterranean islands. Crete biggest and most populated island Greece, characterized by limited surface waters strong dependence on groundwater sources as primary source natural water supply for extensive agricultural activity human use. Freshwater demand in has increased notably last decades. The Geropotamos aquifer located north-central coast freshwater management a delicate balance with...

Summary In an experiment with roses grown hydroponically, a low (0.3 mM) and high (2 level of silicon were combined (0.8 (40 NaCl concentration in the nutrient solution supplied to crop. The aim was detect possible beneficial effects on plant growth, yield flower quality test whether deleterious NaCl-salinity could be mitigated by increasing Si root zone. Silicon added form water- soluble potassium silicate compound. electrical conductivity (EC) solutions concentrations 1.8 6.1 dS m -1 ,...

Two marine bivalves, Mytilus galloprovincialis and Callista chione, were exposed to various concentrations of cadmium nickel (0.5, 1.0, 2.5 20 ppm), for days, plus 10 days' depuration period, in a laboratory experiment. Animals from each experimental condition dissected the bioaccumulation distribution Cd Ni determined their gills, mantles remaining bodies. The Fe Zn also measured. Heavy metal tolerance, bioconcentration heavy metals tissues considerably different M. C. chione: (i) both...

Several groups have recently investigated the kinetic effects of biochemical treatments, site-directed mutagenesis, or substitution essential cofactors on stepwise, water-oxidizing chemistry catalyzed by Photosystem II. Consistently, these studies show evidence for a slowing final, oxygen-releasing step, S3 → S0, catalytic cycle. To degree, some this work also shows earlier S-state transitions. study processes in more detail, we effect replacing Ca2+ with Sr2+on rates transitions using...

The importance of the N-terminal domain manganese stabilizing protein in binding to photosystem II has been previously demonstrated [Eaton-Rye and Murata (1989) Biochim. Biophys. Acta 977, 219-226; Odom Bricker (1992) Biochemistry 31, 5616-5620]. In this paper, we report results from a systematic study functional structural consequences elongation truncation protein. Precursor is unprocessed wild-type protein, which carries an extension 84 amino acids form its chloroplastic signal peptide....

Manganese-stabilizing protein of photosystem II, an intrinsically disordered polypeptide, contains a high ratio charged to hydrophobic amino acid residues. Arg151 and Arg161 are conserved in all known MSP sequences. To examine the role these basic residues structure function, three mutants spinach MSP, R151G, R151D, R161G, were produced. Here, we present evidence that replacement or yields proteins have lower PSII binding affinity, functionally deficient even though about 2 mol mutant...

The extrinsic manganese stabilizing protein of photosystem II is required for Mn retention by the O2-evolving complex, accelerates rate O2 evolution, and protects photosytem against photoinhibition. We report results from studies in vitro reconstitution spinach with recombinant C-terminal deletions two, three, four amino acids. were result amber mutations introduced site-directed mutagenesis. Removal dipeptide (Glu-Gln) did not diminish ability either to rebind or restore high rates...

In solution, Manganese Stabilizing Protein, the polypeptide which is responsible for structural and functional integrity of manganese cluster in photosystem II, a natively unfolded protein with prolate ellipsoid shape [Lydakis-Simantiris et al. (1999) Biochemistry 38, 404−414; Zubrzycki (1998) 37, 13553−13558]. The C-terminal tripeptide Protein was shown to be critical binding II restoration O2 evolution activity [Betts 14230−14236]. Here, we report new biochemical, hydrodynamic,...

Depletion of Ca2+ and/or Cl- ions from PSII membranes blocks the electron-transfer reactions that precede O2 evolution on oxidizing side enzyme. Illumination these inhibited preparations at 273 K generates a paramagnetic species is detectable by low-temperature (T < 20 K) EPR as signal in g = 2 region, 90-230 G wide, depending treatment has undergone. This recently been assigned to YZ* magnetic interaction with manganese cluster its S2 state [Gilchrist et al. (1995) Proc. Natl. Acad. Sci....

Depletion of Ca2+ and/or Cl- ions from PSII membranes blocks the electron-transfer reactions that precede O2 evolution on oxidizing side enzyme. Illumination these inhibited preparations at 273 K generates a paramagnetic species is detectable by low-temperature (T < 20 K) EPR as signal in g = 2 region, 90−230 G wide, depending treatment has undergone. This recently been assigned to YZ• magnetic interaction with manganese cluster its S2 state [Gilchrist et al. (1995) Proc. Natl. Acad. Sci....