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Wyszukujesz frazę "diphosphate" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Cloning, expression and characterization of thermostable YdaP from Bacillus licheniformis 9A
Autorzy:
Wani Lako, Joseph
Yengkopiong, Jada
Stafford, William
Tuffin, Marla
Cowan, Don
Powiązania:
https://bibliotekanauki.pl/articles/1038524.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Bacillus licheniformis
pyruvate oxidase
YdaP
thiamine diphosphate enzyme
Opis:
The Bacillus licheniformis ydaP gene encodes for a pyruvate oxidase that catalyses the oxidative decarboxylation of pyruvate to acetate and CO2. The YdaP form of this enzyme was purified about 48.6-folds to homogeneity in three steps. The enzyme was recovered in a soluble form and demonstrated significant activity on pyruvate using 2, 6-dichlorophenolindophenol (DCPIP) as an artificial electron acceptor. HPLC analysis of the YdaP-enzyme catalysed conversion of pyruvate showed acetate as the sole product, confirming the putative identity of pyruvate oxidase. Analysis of the substrate specificity showed that the YdaP enzyme demonstrated preference for short chain oxo acids; however, it was activated by 1% Triton X-100. The YdaP substrate-binding pocket from the YdaP protein differed substantially from the equivalent site in all of the so far characterized pyruvate oxidases, suggesting that the B. licheniformis YdaP might accept different substrates. This could allow more accessibility of large substrates into the active site of this enzyme. The thermostability and pH activity of the YdaP enzyme were determined, with optimums at 50ºC and pH 5.8, respectively. The amino acid residues forming the catalytic cavity were identified as Gln460 to Ala480.
Źródło:
Acta Biochimica Polonica; 2018, 65, 1; 59-66
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional relationships between the Saccharomyces cerevisiae cis-prenyltransferases required for dolichol biosynthesis.
Autorzy:
Grabińska, Kariona
Sosińska, Grażyna
Orłowski, Jacek
Swiezewska, Ewa
Berges, Thierry
Karst, Francis
Palamarczyk, Grażyna
Powiązania:
https://bibliotekanauki.pl/articles/1041480.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cis-prenyltransferases
farnesyl diphosphate synthase
cross talk
yeast
Opis:
In the yeast Saccharomyces cerevisiae the RER2 and SRT1 genes encode Rer2 and Srt1 proteins with cis-prenyltransferase (cis-PT-ase) activity. Both cis-PT-ases utilize farnesyl diphosphate (FPP) as a starter for polyprenyl diphosphate (dolichol backbone) formation. The products of the Rer2 and Srt1 proteins consist of 14-17 and 18-23 isoprene units, respectively. In this work we demonstrate that deletion or overexpression of SRT1 up-regulates the activity of Rer2p and dolichol content. However, upon overexpression of SRT1, preferential synthesis of longer-chain dolichols and a decrease in the amount of the shorter species are observed. Furthermore, overexpression of the ERG20 gene (encoding farnesyl diphosphate synthase, Erg20p) induces transcription of SRT1 mRNA and increases the levels of mRNA for RER2 and DPM1 (dolichyl phosphate mannose synthase, Dpm1p). Subsequently the enzymatic activity of Rer2p and dolichol content are also increased. However, the amount of Dpm1p or its enzymatic activity remain unchanged.
Źródło:
Acta Biochimica Polonica; 2005, 52, 1; 221-232
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The interaction of two ligand containing electroplating solutions. Final decontamination
Autorzy:
Pigaga, A.
Selskis, A.
Juškénas, R.
Sveikauskaité, A.
Powiązania:
https://bibliotekanauki.pl/articles/346989.pdf
Data publikacji:
2002
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
diphosphate
copper
zinc
ammonium
electroplating
rinsing water
decontamination
Opis:
We suggested previously a cheap and simple way to decontaminate two ligand-containing rinsing waters of metal finishing. Both copper diphosphate containing rinsing wastewater and acidic zinc ammonium containing rinsing wastewater may be decontaminated by mixing with each other, which results in precipitation of solid solutions of copper-zinc-potassium-ammonium diphosphates. This way of decontamination requires no expensive reagents since only a small amount of H2SO4 is needed for pH adjustment. 80-99.5 % of environmentally dangerous substances, viz. zinc, copper and diphosphate, are removed from the mixture. However, Cu2+ and Zn2+ amounts in filtrates significantly exceed discharge consent level (DCL). Moreover, high concentrations of undesirable diphosphate and ammonium ions, which cause the eutrophication of natural water reservoirs, are present in the filtrates. Depending on the waste water composition of the specific plant and the environment protection requirements the goals of the decontamination may be as follows: 1.) To remove Cu2+ and Zn2+ ions below DCL, 2.) To remove Cu2+ and Zn2+ ions below DCL and additionally to lower the amount of phosphates, 3.) To remove Cu2+ and Zn2+ ions below DCL and additionally to lower the amount of phosphates and ammonium. Our investigation has shown, that goal 1 can be easily and cheaply achieved in industry by using lime, goal 2 – by using lime and spent steel etching solution or phosphogypsum. Goal 3 was achieved by precipitating barely soluble fine crystalline MgNH4PO4 .6H2O. It has been determined, that at optimal conditions as much as 95% of NH4 + ions are precipitated, both residual c Cu2+ and c Zn2+ < DCL, and the concentration of soluble phosphates is reduced 5-40 fold.
Źródło:
Ars Separatoria Acta; 2002, 1; 138-148
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short-term regulation of the mammalian pyruvate dehydrogenase complex
Autorzy:
Strumiło, Sławomir
Powiązania:
https://bibliotekanauki.pl/articles/1041314.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
pyruvate dehydrogenase complex
thiamine diphosphate
phosphorylation
dephosphorylation
regulation
allosteric effect
Opis:
In this minireview the main mechanism of control of mammalian pyruvate dehydrogenase complex (PDHC) activity by phosphorylation-dephosphorylation is presented in the first place. The information recently obtained in several laboratories includes new data about isoforms of the PDH converting enzymes (kinase and phosphatase) and their action in view of short-term regulation of PDHC. Moreover, interesting influence of exogenous thiamine diphosphate (TDP) and some divalent cations, especially Mn2+, on the kinetic parameters of PDHC saturated with endogenous tightly bound TDP, is discussed. This influence causes a shortening of the lag-phase of the catalyzed reaction and a strong decrease of the Km value of PDHC mainly for pyruvate. There are weighty arguments that the effects have an allosteric nature. Thus, besides reversible phosphorylation, also direct manifold increase of mammalian PDHC affinity for the substrate by cofactors seems an important aspect of its regulation.
Źródło:
Acta Biochimica Polonica; 2005, 52, 4; 759-764
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Isoprenoid biosynthesis via 1-deoxy-D-xylulose 5-phosphate/2-C- methyl-D-erythritol 4-phosphate (DOXP/MEP) pathway.
Autorzy:
Wanke, Małgorzata
Skorupinska-Tudek, Karolina
Swiezewska, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/1044096.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
isoprenoids
isopentenyl diphosphate
DOXP/MEP pathway
MVA pathway
pyruvate
glyceraldehyde phosphate
Opis:
Higher plants, several algae, bacteria, some strains of Streptomyces and possibly malaria parasite Plasmodium falciparum contain the novel, plastidic DOXP/MEP pathway for isoprenoid biosynthesis. This pathway, alternative with respect to the classical mevalonate pathway, starts with condensation of pyruvate and glyceraldehyde-3-phosphate which yields 1-deoxy-D-xylulose 5-phosphate (DOXP); the latter product can be converted to isopentenyl diphosphate (IPP) and eventually to isoprenoids or thiamine and pyridoxal. Subsequent reactions of this pathway involve transformation of DOXP to 2-C-methyl-D-erythritol 4-phosphate (MEP) which after condensation with CTP forms 4-diphosphocytidyl-2-C-methyl-D-erythritol (CDP-ME). Then CDP-ME is phosphorylated to 4-diphosphocytidyl-2-C-methyl-D-erythritol 2-phosphate (CDP-ME2P) and to 2-C-methyl-D-erythritol-2,4-cyclodiphosphate (ME-2,4cPP) which is the last known intermediate of the DOXP/MEP pathway. Formation of IPP and dimethylallyl diphosphate (DMAPP) from ME-2,4cPP still requires clarification. This novel pathway appears to be involved in biosynthesis of carotenoids, phytol (side chain of chlorophylls), isoprene, mono-, di-, tetraterpenes and plastoquinone whereas the mevalonate pathway is responsible for formation of sterols, sesquiterpenes and triterpenes. Several isoprenoids were found to be of mixed origin suggesting that some exchange and/or cooperation exists between these two pathways of different biosynthetic origin. Contradictory results described below could indicate that these two pathways are operating under different physiological conditions of the cell and are dependent on the developmental state of plastids.
Źródło:
Acta Biochimica Polonica; 2001, 48, 3; 663-672
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nucleoside diphosphate kinase isoforms regulated by phytochrome A isolated from oat coleoptiles
Autorzy:
Hetmann, Anna
Kowalczyk, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/1040648.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
phytochrome A nuclear import
phytochrome A
NDPK isoforms
NDPK (nucleoside diphosphate kinase)
Opis:
Nucleoside diphosphate kinase (NDPK) (EC 2.7.4.6), the enzyme transferring the phosphate residue from ATP to nucleoside diphosphates, is localized mainly in the cytoplasm and mitochondria and in smaller amounts in cell nuclei and the microsomal fraction. Exposure of etiolated oat seedlings to red light causes an increase of the enzyme activity by about 42% in nuclear fraction, 7% in etioplastic and 14% in postetioplastic fraction. Endogenous phytochrome A, as visualized by an immunochemical method, translocates from the cytoplasm into the nucleus upon red, far-red or white light activation. Nuclei purified from oat seedlings contain two, and the postnuclear fraction four easily separated forms of NDPK. One of the nuclear isoforms (In) and one isoform isolated from the postnuclear fraction (IIpn) are activated by red light in the presence of phytochrome A purified from etiolated oat coleoptiles. Both phytochrome A-activated NDPKs purified to electrophoretic homogeneity have the same molecular mass (17-18 kDa) determined by SDS/PAGE. Both enzymes in the native form have similar molecular masses (71 and 63 kDa).
Źródło:
Acta Biochimica Polonica; 2009, 56, 1; 143-154
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of thiamine uptake and utilization in Candida spp. subjected to oxidative stress
Autorzy:
Wolak, Natalia
Tomasi, Massimo
Kozik, Andrzej
Rapala-Kozik, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1038981.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
vitamin B1
thiamine diphosphate-dependent enzymes
antioxidants
reactive oxygen species
Candida spp.
Opis:
Candida species are associated with an increasing number of life-threatening infections (candidiases), mainly due to the high resistance of these yeast-like fungi to antifungal drugs and oxidative stress. Recently, thiamine (vitamin B1) was found to alleviate stress responses in Saccharomyces cerevisiae; however, thiamine influence on defense systems in pathogenic fungi has never been investigated. The current work was aimed to elucidate the role of thiamine in stress reactions of C. albicans, C. glabrata, C. tropicalis and C. dubliniensis, subjected to hydrogen peroxide treatment. As compared to S. cerevisiae, Candida strains exposed to oxidative stress showed: (i) a much higher dependence on exogenous thiamine; (ii) an increased demand for thiamine diphosphate (TDP) and TDP-dependent enzyme, transketolase; (iii) no changes in gene expression of selected stress markers - superoxide dismutase and catalase - depending on thiamine availability in medium; (iv) a similar decrease of reactive oxygen species (ROS) generation in the presence of thiamine. Moreover, the addition of therapeutic doses of thiamine to yeast culture medium revealed differences in its accumulation between various Candida species. The current findings implicate that the protective action of thiamine observed in S. cerevisiae differs significantly form that in pathogenic Candida strains, both in terms of the cofactor functions of TDP and the effects on fungal defense systems.
Źródło:
Acta Biochimica Polonica; 2015, 62, 3; 445-455
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat and SDS insensitive NDK dimers are largely stabilised by hydrophobic interaction to form functional hexamer in Mycobacterium smegmatis
Autorzy:
Arumugam, Muthu
Ajitkumar, Parthasarathi
Powiązania:
https://bibliotekanauki.pl/articles/1039575.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
dimer
ANS fluorescence assay
nucleoside diphosphate kinase
hexamer
hydrophobic interaction
oligomerisation
homology modeling
Mycobacterium smegmatis
Opis:
The primary structure and function of nucleoside diphosphate kinase (NDK), a substrate non-specific enzyme involved in the maintenance of nucleotide pools is also implicated to play pivotal roles in many other cellular processes. NDK is conserved from bacteria to human and forms a homotetramer or hexamer to exhibit its biological activity. However, the nature of the functional oligomeric form of the enzyme differs among different organisms. The functional form of NDKs from many bacterial systems, including that of the human pathogen, Mycobacterium tuberculosis (MtuNDK), is a hexamer, although some bacterial NDKs are tetrameric in nature. The present study addresses the oligomeric property of MsmNDK and how a dimer, the basic subunit of a functional hexamer, is stabilized by hydrogen bonds and hydrophobic interactions. Homology modeling was generated using the three-dimensional structure of MtuNDK as a template; the residues interacting at the monomer-monomer interface of MsmNDK were mapped. Using recombinant enzymes of wild type, catalytically inactive mutant, and monomer-monomer interactive mutants of MsmNDK, the stability of the dimer was verified under heat, SDS, low pH, and methanol. The predicted residues (Gln17, Ser24 and Glu27) were engaged in dimer formation, however the mutated proteins retained the ATPase and GTPase activity even after introducing single (MsmNDK- Q17A, MsmNDK-E27A, and MsmNDK-E27Q) and double (MsmNDK-E27A/Q17A) mutation. However, the monomer-monomer interaction could be abolished using methanol, indicating the stabilization of the monomer-monomer interaction by hydrophobic interaction.
Źródło:
Acta Biochimica Polonica; 2013, 60, 2; 199-207
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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