66 research outputs found
Red clover (Trifolium pratense L.): Identification and characterization of phenolic compounds and protective action against oxidative stress and inflammation
Red clover (Trifolium pratense L.), a widely used feed crop, has recently received considerable interest as a valuable source of phenolic compounds with multiple potential protective functions. It is a rich source of isoflavonoids, plant secondary metabolites widely distributed in the Leguminosae family
Cystathionine beta-Synthase (CBS) Domain-containing Pyrophosphatase as a Target for Diadenosine Polyphosphates in Bacteria
Among numerous proteins containing pairs of regulatory cystathionine beta-synthase (CBS) domains, family II pyrophosphatases (CBS-PPases) are unique in that they generally contain an additional DRTGG domain between the CBS domains. Adenine nucleotides bind to the CBS domains in CBS-PPases in a positively cooperative manner, resulting in enzyme inhibition (AMP or ADP) or activation (ATP). Here we show that linear P-1,P-n-diadenosine 5'-polyphosphates (Ap(n)As, where n is the number of phosphate residues) bind with nanomolar affinity to DRTGG domain-containing CBS-PPases of Desulfitobacterium hafniense, Clostridium novyi, and Clostridium perfringens and increase their activity up to 30-, 5-, and 7-fold, respectively. Ap(4)A, Ap(5)A, and Ap(6)A bound noncooperatively and with similarly high affinities to CBS-PPases, whereas Ap(3)A bound in a positively cooperative manner and with lower affinity, like mononucleotides. All Ap(n)As abolished kinetic cooperativity (non-Michaelian behavior) of CBS-PPases. The enthalpy change and binding stoichiometry, as determined by isothermal calorimetry, were similar to 10 kcal/mol nucleotide and 1 mol/mol enzyme dimer for Ap(4)A and Ap(5)A but 5.5 kcal/mol and 2 mol/mol for Ap(3)A, AMP, ADP, and ATP, suggesting different binding modes for the two nucleotide groups. In contrast, Eggerthella lenta and Moorella thermoacetica CBS-PPases, which contain noDRTGG domain, were not affected by Ap(n)As and showed no enthalpy change, indicating the importance of the DTRGG domain for Ap(n)A binding. These findings suggest that Ap(n)As can control CBS-PPase activity and hence affect pyrophosphate level and biosynthetic activity in bacteria.</p
Residue Network Involved in the Allosteric Regulation of Cystathionine β-Synthase Domain-Containing Pyrophosphatase by Adenine Nucleotides
Inorganic pyrophosphatase containing regulatory cystathionine β-synthase
(CBS) domains (CBS-PPase) is inhibited by adenosine monophosphate (AMP)
and adenosine diphosphate and activated by adenosine triphosphate (ATP)
and diadenosine polyphosphates; mononucleotide binding to CBS domains
and substrate binding to catalytic domains are characterized by positive
cooperativity. This behavior implies three pathways for regulatory
signal transduction — between regulatory and active sites, between two
active sites, and between two regulatory sites. Bioinformatics analysis
pinpointed six charged or polar amino acid residues of Desulfitobacterium hafniense
CBS-PPase as potentially important for enzyme regulation. Twelve mutant
enzyme forms were produced, and their kinetics of pyrophosphate
hydrolysis was measured in wide concentration ranges of the substrate
and various adenine nucleotides. The parameters derived from this
analysis included catalytic activity, Michaelis constants for two active
sites, AMP-, ATP-, and diadenosine tetraphosphate-binding constants for
two regulatory sites, and the degree of activation/inhibition for each
nucleotide. Replacements of arginine 295 and asparagine 312 by alanine
converted ATP from an activator to an inhibitor and markedly affected
practically all the above parameters, indicating involvement of these
residues in all the three regulatory signaling pathways. Replacements of
asparagine 312 and arginine 334 abolished or reversed kinetic
cooperativity in the absence of nucleotides but conferred it in the
presence of diadenosine tetraphosphate, without effects on
nucleotide-binding parameters. Modeling and molecular dynamics
simulations revealed destabilization of the subunit interface as a
result of asparagine 312 and arginine 334 replacements by alanine,
explaining abolishment of kinetic cooperativity. These findings identify
residues 295, 312, and 334 as crucial for CBS-PPase regulation via CBS
domains.</p
Autophagy Activation Clears ELAVL1/HuR-Mediated Accumulation of SQSTM1/p62 during Proteasomal Inhibition in Human Retinal Pigment Epithelial Cells
Hyvä työ, pidempi työura -hanke Boliden Harjavalta Oy:ssä
Opinnäytetyön tarkoituksena on selvittää Boliden Harjavalta Oy:ssä vuoden 2011 alussa alkaneen työhyvinvointihankkeen (Hyvä työ, pidempi työura) vaikuttavuutta yrityksen henkilöstön työhyvinvointiin. Tarkastelun kohteena ovat työpaikan kaikki kolme henkilöstöryhmää (työntekijät, toimihenkilöt, ylemmät toimihenkilöt). Tämän lisäksi arvioidaan työhyvinvointihankkeen vaikutuksia eri sukupuoliin ja yli 55-vuotiaisiin henkilöihin. Viimeksi mainittu ryhmä on yksi hankkeen pääkohderyhmistä. Hankkeen päätavoitteena on luoda työpaikalle olosuhteet, jotka mahdollistavat työuran jatkumisen 1-2 vuotta pidempään. Tämän tavoitteen toteuman arviointia on kuitenkin vaikea tehdä tässä vaiheessa koska muutokset asiassa ovat hitaita. Lisäksi työn perusteella on tarkoitus arvioida projektin vaikutusta yrityksen toimintaan liittyviin asioihin. Näitä ovat sairauspoissaolot, aloiteaktiivisuus ja työturvallisuus. Projekti jatkuu ainakin vuoden 2013 loppuun asti. Toimenpiteiden kokonaisvaikutus tullaan näkemään myöhemmin.The purpose of this thesis was to clear up the influences of the Boliden Harjavalta Oy’s well – being project (Good work, longer working career) that started in the beginning of year 2011. All three personnel groups (blue-collared workers, white-collared workers, managers) were under review. In addition to this the results were examined in male and female level and also in over 55 – year-old group. The last mentioned group consists of the project’s main target workers. The objective of the project is to create such working conditions that make it possible to work 1-2 years longer. The realization of this target cannot be estimated at the moment, because changes in retirement ages are slow, so the results remain to be seen later. The goal of this thesis was also to evaluate this project’s effect to facts that are related to company’s functions, such as sick-leave frequency, the number of initiatives and safety situation. The project will continue at least to year 2013. So, the full effect of the actions that are realized during the project can be seen later
Geochemical Mapping in Europe
The Forum of European Geological Surveys (FOREGS) includes Geological Surveys from 34 European countries and is responsible for co-ordinating Geological Survey activities in Europe. The FOREGS Geochemistry Task Group was established in 1994 to supervise European geochemical mapping policy for environmental, legislative, resource-management and scientific purposes. The task group comprises representatives from five countries, charged initially with the compilation of an inventory of geochemical data within FOREGS countries. The preparation of European Geochemical Baseline maps will involve the integration of different national datasets following the recommendations of the International Geological Correlation Programme (IGCP) Project 259 “International Geochemical Mapping”. Results of the inventory show that most geochemical surveys in Europe conform to the IGCP 259 recommendations. Stream sediment (26% coverage), surface water (19% coverage), soil/till (21% coverage) and radiometric data (19% coverage) are the most extensive sample types, and the majority of surveys (81%) have been carried out at sampling densities of ≤ 1 sample per 100 km2. Most filtered-water surveys are based on a filter size of 0.45µm, and 83% of stream sediment surveys collect samples sieved at 100-200 µm. The collection of the Global Reference Network (GRN) samples recommended by IGCP 259 to provide internationally standardised geochemical data and the careful use of statistical and map-generation techniques should facilitate the levelling of different national datasets and preparation of a European Geochemical Baseline
- …