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Wyświetlanie 1-15 z 16
Tytuł:
Kinetics and specificity of guinea pig liver aldehyde oxidase and bovine milk xanthine oxidase towards substituted benzaldehydes.
Autorzy:
Panoutsopoulos, Georgios
Beedham, Christine
Powiązania:
https://bibliotekanauki.pl/articles/1041542.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
xanthine oxidase
dopamine
benzaldehydes
aldehyde oxidase
protocatechuic aldehyde
isovanillin
Opis:
Molybdenum-containing enzymes, aldehyde oxidase and xanthine oxidase, are important in the oxidation of N-heterocyclic xenobiotics. However, the role of these enzymes in the oxidation of drug-derived aldehydes has not been established. The present investigation describes the interaction of eleven structurally related benzaldehydes with guinea pig liver aldehyde oxidase and bovine milk xanthine oxidase, since they have similar substrate specificity to human molybdenum hydroxylases. The compounds under test included mono-hydroxy and mono-methoxy benzaldehydes as well as 3,4-dihydroxy-, 3-hydroxy-4-methoxy-, 4-hydroxy-3-methoxy-, and 3,4-dimethoxy-benzaldehydes. In addition, various amines and catechols were tested with the molybdenum hydroxylases as inhibitors of benzaldehyde oxidation. The kinetic constants have shown that hydroxy-, and methoxy-benzaldehydes are excellent substrates for aldehyde oxidase (Km values 5×10-6 M to 1×10-5 M) with lower affinities for xanthine oxidase (Km values around 10-4 M). Therefore, aldehyde oxidase activity may be a significant factor in the oxidation of the aromatic aldehydes generated from amines and alkyl benzenes during drug metabolism. Compounds with a 3-methoxy group showed relatively high Vmax values with aldehyde oxidase, whereas the presence of a 3-hydroxy group resulted in minimal Vmax values or no reaction. In addition, amines acted as weak inhibitors, whereas catechols had a more pronounced inhibitory effect on the aldehyde oxidase activity. It is therefore possible that aldehyde oxidase may be critical in the oxidation of the analogous phenylacetaldehydes derived from dopamine and noradrenaline.
Źródło:
Acta Biochimica Polonica; 2004, 51, 3; 649-663
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enzymatic oxidation of phthalazine with guinea pig liver aldehyde oxidase and liver slices: inhibition by isovanillin
Autorzy:
Panoutsopoulos, Georgios
Beedham, Christine
Powiązania:
https://bibliotekanauki.pl/articles/1041506.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
xanthine oxidase
phthalazine
aldehyde oxidase
liver slices
disulfiram
isovanillin
allopurinol
Opis:
The enzymes aldehyde oxidase and xanthine oxidase catalyze the oxidation of a wide range of N-heterocycles and aldehydes. These enzymes are widely known for their role in the metabolism of N-heterocyclic xenobiotics where they provide a protective barrier by aiding in the detoxification of ingested nitrogen-containing heterocycles. Isovanillin has been shown to inhibit the metabolism of aromatic aldehydes by aldehyde oxidase, but its inhibition towards the heterocyclic compounds has not been studied. The present investigation examines the oxidation of phthalazine in the absence and in the presence of the inhibitor isovanillin by partially purified aldehyde oxidase from guinea pig liver. In addition, the interaction of phthalazine with freshly prepared guinea pig liver slices, both in the absence and presence of specific inhibitors of several liver oxidizing enzymes, was investigated. Aldehyde oxidase rapidly converted phthalazine into 1-phthalazinone, which was completely inhibited in the presence of isovanillin (a specific inhibitor of aldehyde oxidase). In freshly prepared liver slices, phthalazine was also rapidly converted to 1-phthalazinone. The formation of 1-phthalazinone was completely inhibited by isovanillin, whereas disulfiram (a specific inhibitor of aldehyde dehydrogenase) only inhibited 1-phthalazinone formation by 24% and allopurinol (a specific inhibitor of xanthine oxidase) had little effect. Therefore, isovanillin has been proved as an inhibitor of the metabolism of heterocyclic substrates, such as phthalazine, by guinea pig liver aldehyde oxidase, since it had not been tested before. Thus it would appear from the inhibitor results that aldehyde oxidase is the predominant enzyme in the oxidation of phthalazine to 1-phthalazinone in freshly prepared guinea pig liver slices, whereas xanthine oxidase only contributes to a small extent and aldehyde dehydrogenase does not take any part.
Źródło:
Acta Biochimica Polonica; 2004, 51, 4; 943-951
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polyphenol oxidase from wheat bran is a serpin
Autorzy:
Yamasaki, Yoshiki
Konno, Haruyoshi
Noda, Kazuhiko
Powiązania:
https://bibliotekanauki.pl/articles/1040750.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
polyphenol oxidase
serpin
wheat bran
Opis:
Polyphenol oxidase (PPO; EC 1.10.3.2) was isolated from wheat bran by a procedure that included ammonium sulfate fractionation, batch adsorption by DEAE-cellulofine, CM-cellulofine column chromatography, DEAE-cellulofine column chromatography, preparative isoelectric focusing, adsorption on the membrane of a Vivapure Q Maxi H spin column, and heat treatment. These procedures led to 150-fold purification with 4.2% recovery. The PPO was homogeneous by SDS/PAGE. The relative molecular weight of the PPO was estimated to be 37000 based on its mobility in SDS/PAGE. The isoelectric point of the PPO was 4.4. The Km values of the PPO for caffeic acid, chlorogenic acid, pyrocatechol, 4-methyl catechol and l-DOPA as substrates were 0.077, 0.198, 1.176, 1.667 and 4.545 mM. The PPO was strongly inhibited by tropolone. The Ki value for tropolone is 2.2 × 10-7 M. The sequence of the 15 N-terminal amino-acid residues was determined to be ATDVRLSIAHQTRFA, which was identical to those of serpin from Triticum aestivum and protein Z from Hordeum vulgare. The PPO strongly inhibited the activity of trypsin, which is an enzyme of serine proteases; 50% inhibition was observed with 1.5 × 10-7 M PPO. The Ki value for PPO is 2.3 × 10-8 M. The wheat bran PPO should be a very important protein for protecting wheat against disease, virus, insect and herbivore damages by both the activities of PPO and protease inhibitor.
Źródło:
Acta Biochimica Polonica; 2008, 55, 2; 325-328
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Alternative oxidase in higher plants.
Autorzy:
Juszczuk, Izabela
Rychter, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1043421.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
mitochondrial respiratory chain
ubiquinol
post-translational/post-transcriptional regulation
respiration
reactive oxygen species
alternative oxidase
Opis:
Plant respiratory chain branches at the level of ubiquinone from where the electrons flow through the cytochrome pathway or to alternative oxidase. Transfer of electrons from ubiquinone to oxygen by alternative oxidase has a non-protonmotive character and, by bypassing two sites of H+ pumping in complexes III and IV, lowers the energy efficiency of respiration. In this paper we review theoretical and experimental studies about the structure and possible function of alternative oxidase. The evidence for specific gene expression dependent on the physiological, developmental and environmental conditions is also described. We underline the physiological role of alternative oxidase as a "survival" protein that allows plants to cope with the stressful environment.
Źródło:
Acta Biochimica Polonica; 2003, 50, 4; 1257-1271
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oxalic acid degradation by a novel fungal oxalate oxidase from Abortiporus biennis
Autorzy:
Grąz, Marcin
Rachwał, Kamila
Zan, Radosław
Jarosz-Wilkołazka, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1038790.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
oxalate oxidase
oxalic acid
Abortiporus biennis
Opis:
Oxalate oxidase was identified in mycelial extracts of a basidiomycete Abortiporus biennis strain. Intracellular enzyme activity was detected only after prior lowering of the pH value of the fungal cultures by using oxalic or hydrochloric acids. This enzyme was purified using size exclusion chromatography (Sephadex G-25) and ion-exchange chromatography (DEAE-Sepharose). This enzyme exhibited optimum activity at pH 2 when incubated at 40°C, and the optimum temperature was established at 60°C. Among the tested organic acids, this enzyme exhibited specificity only towards oxalic acid. Molecular mass was calculated as 58 kDa. The values of Km for oxalate and Vmax for the enzyme reaction were 0.015 M and 30 mmol min-1, respectively.
Źródło:
Acta Biochimica Polonica; 2016, 63, 3; 595-600
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The mechanism of azide activation of polyphenol oxidase II from tobacco.
Autorzy:
Shi, Chunhua
Liu, Qingliang
Dai, Ya
Xie, Yongshu
Xu, Xiaolong
Powiązania:
https://bibliotekanauki.pl/articles/1043711.pdf
Data publikacji:
2002
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
polyphenol oxidase (PPO)
azide activation
peroxide activation
superoxide activation
copper proteins
Opis:
So far, azide has been consistently reported to act as an inhibitor of metal enzymes, especially copper proteins. The present work shows that azide can also act as an activator of polyphenol oxidase II (PPO II) from tobacco leaves. From0 the square-wave voltammetry of native PPO II, peroxide-PPO II complex and azide-PPO II complex, the reduction of nitro blue tetrazolium by the enzymes and activation of PPO II by peroxide it follows that the binding of azide to PPO II induces the formation of CuO(2)(2-)Cu in the active site of PPO II from CuO(2)(-)Cu in native PPO II. The reason for azide acting as an activator can be attributed to azide complexing with PPO II, thus inducing the formation of CuO(2)(2-)Cu, which is the active site of the peroxide-PPO II complex in which peroxide plays the role of activator.
Źródło:
Acta Biochimica Polonica; 2002, 49, 4; 1029-1035
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of pH on the activity and structure of choline oxidase from Alcaligenes species
Autorzy:
Hekmat, Azadeh
Saboury, Ali
Moosavi-Movahedi, Ali
Ghourchian, Hedayatollah
Ahmad, Faizan
Powiązania:
https://bibliotekanauki.pl/articles/1040713.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
optimum pH
choline oxidase
nile red
glycine-betaine
Opis:
A reversible effect of pH on the ionization of amino-acid residues at the active center of choline oxidase was observed near the optimum pH (8). Inactivation of choline oxidase took place in the pH ranges 3-6 and 9-11, in which irreversible changes in the structure occur leading to the enzyme inactivation. The first order rate constants of the enzyme's inactivation at various pH values were estimated for the irreversible changes. The Arrhenius analysis revealed no significant changes in the activation enthalpy, while an increase in the activation entropy reflected an increase in the conformational freedom.
Źródło:
Acta Biochimica Polonica; 2008, 55, 3; 549-557
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metformin reduces NAD(P)H oxidase activity in mouse cultured podocytes through purinergic dependent mechanism by increasing extracellular ATP concentration
Autorzy:
Piwkowska, Agnieszka
Rogacka, Dorota
Jankowski, Maciej
Angielski, Stefan
Powiązania:
https://bibliotekanauki.pl/articles/1039452.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
AMP-activated kinase
free radicals
metformin
NAD(P)H oxidase
podocytes
purinoceptors
Opis:
Hyperglycemia affects the functioning numbers of podocytes and leads to a gradual decline of renal function. The normalization of glucose level is a principle therapeutic goal in diabetic patients and metformin is a popular hypoglycemic drug used in type 2 diabetes mellitus. Metformin activates AMP-activated kinase (AMPK) and decreases NAD(P)H oxidase activity in podocytes leading to reduction of free radical generation. Similar effects are observed after activation of P2 receptors. Therefore, we investigated whether metformin increases extracellular ATP concentration and affects the activities of NAD(P)H oxidase and AMPK through P2 receptors. Experiments were performed on cultured mouse podocytes. NAD(P)H oxidase activity was measured by chemiluminescence and changes in AMPK activity were estimated by immunoblotting against AMPKα-Thr172-P. Metformin increased extracellular ATP concentration by reduction of ecto-ATPase activity, decreased NAD(P)H oxidase activity and increased AMPK phosphorylation. A P2 receptor antagonist, suramin (300 µM), prevented metformin action on NAD(P)H oxidase and AMPK phosphorylation. The data suggests a novel mechanism of metformin action, at least in podocytes. Metformin, which increases extracellular ATP concentration leads to activation of P2 receptors and consequent modulation of the podocytes' metabolism through AMPK and NAD(P)H oxidase which, in turn, may affect podocyte functioning.
Źródło:
Acta Biochimica Polonica; 2013, 60, 4; 607-612
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncoupling proteins in mitochondria of plants and some microorganisms.
Autorzy:
Jarmuszkiewicz, Wiesława
Powiązania:
https://bibliotekanauki.pl/articles/1044176.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
uncoupling protein
alternative oxidase
mitochondria
fatty acid
Opis:
Uncoupling proteins, members of the mitochondrial carrier family, are present in mitochondrial inner membrane and mediate free fatty acid-activated, purine-nucleotide-inhibited H+ re-uptake. Since 1995, it has been shown that the uncoupling protein is present in many higher plants and some microorganisms like non-photosynthetic amoeboid protozoon, Acanthamoeba castellanii and non-fermentative yeast Candida parapsilosis. In mitochondria of these organisms, uncoupling protein activity is revealed not only by stimulation of state 4 respiration by free fatty acids accompanied by decrease in membrane potential (these effects being partially released by ATP and GTP) but mainly by lowering ADP/O ratio during state 3 respiration. Plant and microorganism uncoupling proteins are able to divert very efficiently energy from oxidative phosphorylation, competing for ΔμH+ with ATP synthase. Functional connection and physiological role of uncoupling protein and alternative oxidase, two main energy-dissipating systems in plant-type mitochondria, are discussed.
Źródło:
Acta Biochimica Polonica; 2001, 48, 1; 145-155
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A possible involvement of plasma membrane NAD(P)H oxidase in the switch mechanism of the cell death mode from apoptosis to necrosis in menadione-induced cell injury.
Autorzy:
Niemczyk, Edyta
Majczak, Anna
Hallmann, Anna
Kędzior, Jakub
Woźniak, Michał
Wakabayashi, Takashi
Powiązania:
https://bibliotekanauki.pl/articles/1041516.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
menadione
NADPH oxidase
necrosis
superoxide
apoptosis
Opis:
The effects of inhibitors of plasma membrane NADPH oxidase on menadione-induced cell injury processes were studied using human osteosarcoma 143B cells. The intracellular level of superoxide in the cells treated with menadione for 6 h reached a maximum followed by an abrupt decrease. The population of apoptotic cells detected by Annexin V and propidium iodide double staining also reached its maximum at 6 h of menadione-treatment while that of necrotic cells increased continuously reaching 90% of the total population at 9 h of the treatment. Pretreatment of the cells with inhibitors of NADPH oxidase, including diphenyliodonium chloride, apocynin, N-vanillylnonanamide and staurosporine was effective in lowering the menadione-induced elevations of superoxide, and also in the suppression of the switch of the cell death mode from apoptosis to necrosis in menadione-treated cells except for the case of staurosporine. These results strongly suggest that superoxide generated by NADPH oxidase, besides that generated by the mitochondria, may contribute to the remarkable increase in the intracellular level of superoxide in the cells treated with menadione for 6 h resulting in the switch from apoptosis to necrosis, although a direct evidence of the presence of active and inactive forms of NADPH oxidase in control and menadione-treated 143B cells is lacking at present.
Źródło:
Acta Biochimica Polonica; 2004, 51, 4; 1015-1022
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The ability of new formamidine sugar-modified derivatives of daunorubicin to stimulate free radical formation in three enzymatic systems: NADH dehydrogenase, NADPH cytochrome P450 reductase and xanthine oxidase
Autorzy:
Pawłowska, Jolanta
Tarasiuk, Jolanta
Borowski, Edward
Wąsowska, Małgorzata
Oszczapowicz, Irena
Wolf, C
Powiązania:
https://bibliotekanauki.pl/articles/1044407.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
xanthine oxidase
NADH dehydrogenase
daunorubicin
formamidine derivatives
free radical formation
NADPH cytochrome P540 reductase
Opis:
Some sterically hindered N-substituted derivatives of daunorubicin are known to be poor substrates for NADH dehydrogenase, NADPH cytochrome P450 reductase and xanthine oxidase. In consequence, poor oxygen radical generation by these compounds is observed. In this study we examined a new family of sugar-N-substituted derivatives of daunorubicin bearing a bulky substituent introduced on the nitrogen atom through the amidine spacer. These compounds were found to be very active in radical formation catalyzed by all three studied enzymes. Thus, the introduction of a heterocyclic ring, even if it is bulky but flexible, on the nitrogen atom of daunosamine moiety through the one-atom spacer (amidine group), does not induce the steric hindrance effect on the interaction of daunorubicin derivatives with these flavoprotein enzymes.
Źródło:
Acta Biochimica Polonica; 2000, 47, 1; 141-147
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Endothelial NADH/NADPH-dependent enzymatic sources of superoxide production: relationship to endothelial dysfunction.
Autorzy:
Kalinowski, Leszek
Malinski, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/1043282.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
peroxynitrite
endothelial dysfunction
NAD(P)H oxidase
nitric oxide
superoxide
eNOS
Opis:
There is growing evidence that endothelial dysfunction, which is often defined as the decreased endothelial-derived nitric oxide (NO) bioavailability, is a crucial factor leading to vascular disease states such as hypertension, diabetes, atherosclerosis, heart failure and cigarette smoking. This is due to the fact that the lack of NO in endothelium-dependent vascular disorders contributes to impaired vascular relaxation, platelet aggregation, increased vascular smooth muscle proliferation, and enhanced leukocyte adhesion to the endothelium. During the last several years, it has become clear that reduction of NO bioavailability in the endothelium-impaired function disorders is associated with an increase in endothelial production of superoxide (O2̇̄). Because O2̇̄ rapidly scavenges NO within the endothelium, a reduction of bioactive NO might occur despite an increased NO generation. Among many enzymatic systems that are capable of producing O2̇̄, NAD(P)H oxidase and uncoupled endothelial NO synthase (eNOS) apparently are the main sources of O2̇̄ in the endothelial cells. It seems that O2̇̄ generated by NAD(P)H oxidase may trigger eNOS uncoupling and contribute to the endothelial balance between NO and O2̇̄. That is maintained at diverse levels.
Źródło:
Acta Biochimica Polonica; 2004, 51, 2; 459-469
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of growth at low temperature on the alternative pathway respiration in Acanthamoeba castellanii mitochondria.
Autorzy:
Jarmuszkiewicz, Wiesława
Frączyk, Olaf
Hryniewiecka, Lilla
Powiązania:
https://bibliotekanauki.pl/articles/1044102.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Acanthamoeba castellanii
low temperature adaptation
alternative oxidase
mitochondria
Opis:
Mitochondria of amoeba Acanthamoeba castellanii in addition to the conventional cytochrome pathway possess, like plant mitochondria, a cyanide-resistant alternative quinol oxidase. In mitochondria isolated from amoeba batch culture grown temporarily at low temperature (6°C), higher respiration was accompanied by lower coupling parameters as compared to control culture (grown at 28°C). In the presence of benzohydroxamate, respiratory rates and coupling parameters were similar in both types of mitochondria indicating that growth in cold conditions did not disturb the cytochrome pathway. Increased contribution of alternative oxidase in total mitochondrial respiration in low-temperature-grown amoeba cells was confirmed by calculation of its contribution using ADP/O measurements. Furthermore, in mitochondria from low-temperature- grown cells the content of the alternative oxidase was increased and correlated with the increase in the unstimulated and GMP-stimulated cyanide-resistant respiratory activity. A possible physiological role of higher activity of alternative oxidase as response to growth at a low temperature in unicellular organisms, such as amoeba, is discussed.
Źródło:
Acta Biochimica Polonica; 2001, 48, 3; 729-737
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antioxidative defense to lead stress in subcellular compartments of pea root cells.
Autorzy:
Małecka, Arleta
Jarmuszkiewicz, Wiesława
Tomaszewska, Barbara
Powiązania:
https://bibliotekanauki.pl/articles/1044098.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
lead
superoxide dismutase
Pisum sativum
catalase
peroxisomes
superoxide anion
alternative oxidase
mitochondria
oxidative stress
Opis:
Lead, similar to other heavy metals and abiotic factors, causes many unfavorable changes at the subcellular and molecular levels in plant cells. An increased level of superoxide anion in Pisum sativum root cells treated with 1 mM Pb(NO3)2 evidenced oxidative stress conditions. We found increased activities of enzymatic components of the antioxidative system (catalase and superoxide dismutase) in the cytosol, mitochondrial and peroxisomal fractions isolated from root cells of Pisum sativum grown in modified Hoagland medium in the presence of lead ions (0.5 or 1 mM). Two isoenzyme forms of superoxide dismutase (Cu,Zn-SOD and Mn-SOD) found in different subcellular compartments of pea roots were more active in Pb-treated plants than in control. Increased amount of alternative oxidase accompanied by an increased activity of this enzyme was found in mitochondria isolated from lead-treated roots. These results show that plants storing excessive amounts of lead in roots defend themselves against the harmful oxidative stress caused by this heavy metal.
Źródło:
Acta Biochimica Polonica; 2001, 48, 3; 687-698
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
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
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