Reactive oxygen species are generated by various biological systems,
including NADPH oxidases, xanthine oxidoreductase, and mitochondrial
respiratory enzymes, and contribute to many physiological and pathologi-cal phenomena.
Pyruvate: ferredoxin oxidoreductase (POR; EC 184.108.40.206) catalyzes the thia-mine pyrophosphate-dependent oxidative decarboxylation of pyruvate to
form acetyl-CoA and CO2
. The thermophilic, obligate chemolithoauto-trophic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilusTK-6,
via the reductive tricarboxylic acid cycle.
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Cell-specific expression of tryptophan decarboxylase and 10-hydroxygeraniol oxidoreductase, key genes involved in camptothecin biosynthesis in Camptotheca acuminata Decne (Nyssaceae)
Mycobacterium tuberculosis, the most successful bacterial pathogen, causes
tuberculosis, a disease that still causes more than 2 million deaths per year.
ArylamineN-acetyltransferase is an enzyme that is conserved in most
This work reports on the direct electrochemistry of the
Desulfovibrio gigasaldehyde oxidoreductase (DgAOR), a
molybdenum enzyme of the xanthine oxidase family that
contains three redox-active cofactors: two [2Fe-2S] centers
and a molybdopterin cytosine dinucleotide cofactor. The
voltammetric behavior of the enzyme was analyzed at gold
and carbon (pyrolytic graphite and glassy carbon) elec-trodes. Two different strategies were used: one with the
molecules confined to the electrode surface and a second
withDgAOR in solution....
Protein disulfide oxidoreductases are ubiquitous redox
enzymes that catalyse dithiol–disulfide exchange reactions
with a CXXC sequence motif at their active site. Adisulfide
oxidoreductase, a highly thermostable protein, was isolated
from Pyrococcus furiosus(PfPDO), which is characterized
by two redox sites (CXXC) and an unusual molecularmass.
Its 3D structure at high resolution suggests that it may be
related to the multidomain protein disulfide-isomerase
(PDI), which is currently known only in eukaryotes....
Aldehyde oxidoreductase ofEubacterium acidaminophilum
was purified to homogeneity under strict anaerobic condi-tions using a four-step procedure. The purified enzyme was
present as a monomer with an apparent molecular mass of
67 kDa and contained 6.0± 0.1 iron, 1.1 ± 0.2 tungsten,
about 0.6 mol pterincofactor andzinc, but nomolybdenum.
The enzymeactivitywas induced if amolar excessof electron
donors, such as serine and/or formate, were supplied in the
growth medium compared to readily available electron
acceptors such as glycine betaine....
The Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) from Vibrio alginolyticus was inactivated by reactive oxygen species. Highest Na+-NQR activity was observed in anaerobically prepared membranes that exhibited 1 : 1 coupling of NADH oxidation and Q reduction activities (1.6 UÆmg)1). Optical and EPR spectroscopy documented the presence of b-type cytochromes, a [2Fe)2S] cluster and an organic radical signal in anaerobically pre-
pared membranes from V. alginolyticus.
Prolamellar bodies (PLB) contain two photochemically active forms of the enzyme protochlorophyllide oxidoreductase POR-PChlide640 and POR-PChlide650 (the spectral forms of POR-Chlide complexes with absorption maxima at the indicated wavelengths). Resuspension of maize PLB in media with a pH below 6.8 leads to a rapid conversion of POR-PChlide650 to POR-PChlide640 and a dramatic re-organization of the PLB membrane system. In the absence of excess NADPH, the absorption maximum of the POR complex undergoes a further shift to about 635 nm....
The in vitro Entamoeba histolytica pyruvate:ferredoxin oxidoreductase
(EhPFOR) kinetic properties and the effect of oxidative stress on glycolytic
pathway enzymes and fluxes in live trophozoites were evaluated.EhPFOR
showed a strong preference for pyruvate as substrate over other oxoacids.
The N-termini of the NADPH : protochlorophyllide oxidoreductase (POR)
proteins A and B from barley and POR from pea were determined by acet-ylation of the proteins and selective isolation of the N-terminal peptides
for mass spectrometry de novosequence analysis. We show that the cleav-age sites between the transit peptides and the three mature POR proteins
Human novel reductase 1 (NR1) is an NADPH dependent
diflavin oxidoreductase related to cytochrome P450reduc-tase (CPR). The FAD/NADPH- and FMN-binding
domains of NR1 have been expressed and purified and their
redox properties studied by stopped-flow and steady-state
kinetic methods, and by potentiometry.
The availability of a system for the functional expression of
genes coding formolybdenumhydroxylases is a prerequisite
for the construction of enzyme variants bymutagenesis. For
the expression cloning of quinoline 2-oxidoreductase (Qor)
fromPseudomonas putida86 – that contains the molybdo-pterin cytosine dinucleotide molybdenum cofactor
(Mo-MCD), two distinct [2Fe)2S] clusters and FAD – the
qorMSLgenes were inserted into the broad host range
vector, pJB653, generating pUF1.P. putidaKT2440 and
P. putida86-1Dqor were used as recipients for pUF1....
The last step of the biosynthesis ofl-ascorbic acid (vitamin C) in plants and
animals is catalyzed by l-gulono-1,4-lactone oxidoreductases, which use
bothl-gulono-1,4-lactone and l-galactono-1,4-lactone as substrates. l-Gul-ono-1,4-lactone oxidase is missing in scurvy-prone, vitamin C-deficient ani-mals, such as humans and guinea pigs, which are also highly susceptible to
Pyridine-linked oxidoreductase enzymes ofHelicobacter pylorihave been
implicated in the pathogenesis of gastric disease. Previous studies in this
laboratory examined a cinnamyl alcohol dehydrogenase that was capable
of detoxifying a range of aromatic aldehydes. In the present work, we have
extended these studies to identify and characterize an aldoketo reductase
(AKR) enzyme present in H. pylori.
NADH dehydrogenase activity was characterized in the mitochondrial
lysates of Phytomonas serpens, a trypanosomatid flagellate parasitizing
plants. Two different high molecular weight NADH dehydrogenases were
characterized by native PAGE and detected by direct in-gel activity stain-ing.
NAD(P)H:quinone acceptor oxidoreductases are flavoenzymes expressed in
the cytoplasm of many tissues and afford protection against the cytotoxic
effects of electrophilic quinones by catalyzing a strict two-electron reduc-tion. Such enzymes have been reported from several mammalian sources,
e.g. human, mouse and rat, and from plant species.
Disulfide bonds are required for the stability and function of a large num-ber of proteins. Recently, the results from genome analysis have suggested
an important role for disulfide bonds concerning the structural stabilization
of intracellular proteins from hyperthermophilic Archaea and Bacteria,
contrary to the conventional view that structural disulfide bonds are rare in
proteins from Archaea.
The ESSS protein is a recently identified subunit of mam-malian mitochondrial complex I. It is a relatively small
integral membrane protein (122 amino acids) found in the
b-subcomplex. Genomic sequence database searches reveal
its localization to theX-chromosome inhumans andmouse.
TheESSScDNAfromChinesehamster cellswas clonedand
shown to complement one complementation group of our
previously described mutants with a proposed X-linkage.
Sequence analyses of the ESSS cDNA in these mutants
revealed chain termination mutations. ...
Complex I (NADH:ubiquinone oxidoreductase) is the largest multiprotein
enzyme of the oxidative phosphorylation system. Its assembly in human
cells is poorly understood and no proteins assisting this process have yet
been described. A good candidate is NDUFAF1, the human homologue of
Neurospora crassacomplex I chaperone CIA30. Here, we demonstrate that
NDUFAF1 is a mitochondrial protein that is involved in the complex I