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1.
A particulate cell-free fraction (144,000-X-g pellet) fromNitrobacter agilis catalyzes the acrobic or anaerobic oxidation of NADH. Phosphorylation coupled to the aerobic oxidation of NADH yields P/O
ratios of 1.1. The net formation of ATP coupled to the anaerobic oxidation of NADH by nitrate yields P/NO3 ratios of 0.7. Phosphate esterification is uncoupled by carbonylcyanide-m-chlorophenyl-hydrozone and is sensitive to inhibitors of the electron transport system. 相似文献
2.
The cell-free preparations from autotrophieally grown Pseudomonas saccharophila catalyzed the process of electron transport from H2 or various other organic electron donors to either O2 or NO3? with concomitant ATP generation. The respective ratios with H2 and NADH were 0.63 and 0.73, the respective ratios were 0.57 and 0.54. In contrast, the and ratios with succinate were 0.18 and 0.11, respectively. ATP formation coupled to the oxidation of ascorbate, in the absence or presence of added N,N,N′,N′-tetramethyl-p-phenylenediamine or cytochrome c, could not be detected. Various uncouplers inhibited phosphorylation with either O2 or NO3? as terminal electron acceptors without affecting the oxidation of H2 or other substrates. The NADH oxidation at the expense of O2 or NO3? reduction as well as the associated phosphorylation were inhibited by rotenone and amytal. The aerobic and anaerobic H2 oxidation and coupled ATP synthesis, on the other hand, was unaffected by the flavoprotein inhibitors as well as by the NADH trapping system. The NADH, H2, and succinate-linked electron transport to O2 or NO3? and the associated phosphorylations were sensitive, however, to antimycin A or 2-n-nonyl-4-hydroxyquino-line-N-oxide, and cyanide or azide. The data indicated that although the phosphorylation sites 1 and II were associated with NADH oxidation by O2 or NO3?, the energy conservation coupled to H2 oxidation under aerobic or anaerobic conditions appeared to involve site II only. 相似文献
3.
Isotopic signature of nitrate in two contrasting watersheds of Brush Brook,Vermont, USA 总被引:2,自引:0,他引:2
We used the dual isotope method to study differences in nitrate export in two subwatersheds in Vermont, USA. Precipitation,
soil water and streamwater samples were collected from two watersheds in Camels Hump State Forest, located within the Green
Mountains of Vermont. These samples were analyzed for the δ15N and δ18O of NO3−. The range of δ15N–NO3− values overlapped, with precipitation −4.5‰ to +2.0‰ (n = 14), soil solution −10.3‰ to +6.2‰ (n = 12) and streamwater +0.3‰ to +3.1‰ (n = 69). The δ18O of precipitation NO3− (mean 46.8 ± 11.5‰) was significantly different (P < 0.001) from that of the stream (mean 13.2 ± 4.3‰) and soil waters (mean 14.5 ± 4.2‰) even during snowmelt periods. Extracted
soil solution and streamwater δ18O of NO3− were similar and within the established range of microbially produced NO3−, demonstrating that NO3− was formed by microbial processes. The δ15N and δ18O of NO3− suggests that although the two tributaries have different seasonal NO3− concentrations, they have a similar NO3− source. 相似文献
4.
Iron interference in the quantification of nitrate in soil extracts and its effect on hypothesized abiotic immobilization of nitrate 总被引:3,自引:3,他引:0
Human alteration of the nitrogen cycle has stimulated research on nitrogen cycling in many aquatic and terrestrial ecosystems,
where analyses of nitrate (NO3
−) by standard laboratory methods are common. A recent study by Colman et al. (Biogeochemistry 84:161–169, 2007) identified
a potential analytical interference of soluble iron (Fe) with NO3
− quantification by standard flow-injection analysis of soil extracts, and suggested that this interference may have led Dail
et al. (Biogeochemistry 54:131–146, 2001) to make an erroneous assessment of abiotic nitrate immobilization in prior 15N pool dilution studies of Harvard Forest soils. In this paper, we reproduce the Fe interference problem systematically and
show that it is likely related to dissolved, complexed-Fe interfering with the colorimetric analysis of NO2
−. We also show how standard additions of NO3
− and NO2
− to soil extracts at native dissolved Fe concentrations reveal when the Fe interference problem occurs, and permit the assessment
of its significance for past, present, and future analyses. We demonstrate low soluble Fe concentrations and good recovery
of standard additions of NO3
− and NO2
− in extracts of sterilized Harvard Forest soils. Hence, we maintain that rapid NO3
− immobilization occurred in sterilized samples of the Harvard Forest O horizon in the study by Dail et al. (2001). Furthermore,
additional evidence is accumulating in the literature for rapid disappearance of NO3
− added to soils, suggesting that our observations were not the result of an isolated analytical artifact. The conditions for
NO3
− reduction are likely to be highly dependent on microsite properties, both in situ and in the laboratory. The so-called “ferrous
wheel hypothesis” (Davidson et al., Glob Chang Biol 9:228–236, 2003) remains an unproven, viable explanation for published
observations. 相似文献
5.
The effect of nitrate concentration in the nutrient solution, on yields and nitrate accumulation in the plant, was studied
in Rhodes grass grown in sand culture.
The results showed that optimal yield was achieved in the 7.5meq.L−1 N solution. The optimal NO3−N concentration in the plant canopy may be an indicator of effective N fertilizer use. Increasing N fertilization will only
increase the NO3−N concentration in the plant.
A.R.O. Contribution no. 2244-E, 1987 series. 相似文献
6.
In the presence of purified nitrate reductase (NR) and 1 mM NADH, illuminated pea chloroplasts catalysed reduction of NO3? to NH3 with the concomitant evolution of O2. The rates were slightly less than those for reduction of NO2? to NH3 and O2, evolution by chloroplasts in the absence of NR and NADH (ca 6 μg atoms N/mg Chl/hr). Illuminated chloroplasts quantitatively reduced 0.2 mM oxaloacetate (OAA) to malate. In the presence of an extrachloroplast malate-oxidizing system comprised of NAD-specific malate dehydrogenase (NAD-MDH), NAD, NR and NO3?, illuminated chloroplasts supported OAA-dependent reduction of NO3? to NH3 with the evolution of O2. The reaction did not proceed in the absence of any of these supplements or in the dark but malate could replace OAA. The results are consistent with the reduction of NO3?by reducing equivalents from H2O involving a malate/OAA shuttle. The ratios for O2, evolved: C4-acid supplied and N reduced: C4-acid supplied in certain experiments imply recycling of the C4-acids. 相似文献
7.
J. A. G. Silveira A. R. B. Melo M. O. Martins S. L. Ferreira-Silva R. M. Aragão E. N. Silva R. A. Viégas 《Biologia Plantarum》2012,56(3):575-580
The aim of this study was to test the hypothesis that salinity can affect indirectly the nitrate acquisition by a negative
modulation triggered by glutamine accumulation. Cowpea plants were exposed to a mild NaCl concentration (50 mM) in order to
restrict growth and N-demand. After 21 d, pretreated plants and control plants were supplied with 0, 5 and 10 mM of Ca(NO3)2 for 3 d in absence of NaCl. Salt pretreated plants showed a great limitation in acquisition of NO3
−, indicated by decline in the nitrate uptake rate, NO3
− accumulation, nitrate reductase activity and protein content. The restriction of NO3
− utilization was positively associated with increased glutamine synthetase activity and glutamine accumulation, especially
in roots. 相似文献
8.
The generation time ofP. mirabilis in defined and in complex medium is shorter in the presence of hydrogen acceptors than in their absence. In the presence
of hydrogen acceptors the molar growth yield for glucose and the acetate production are strongly increased. From the molar
growth yield and the acetate production YATP in defined medium was calculated as 5.5 g/mole, whereas in complex medium a value of 12.6 g/mole was obtained. The molar
growth yield, the acetate production, the amount of hydrogen acceptor reduced and YATP were used to calculate P/2e−ratios for phosphorylation coupled to electron transfer to oxygen, nitrate and tetrathionate as respectively 2.80; 1.48 and
1.23 in defined medium. Under anaerobic conditions in the presence of nitrate or tetrathionate as hydrogen acceptor in complex
medium a bend in the growth curve is observed. In the period of rapid growth the P/2e−ratio for nitrate reduction is of the same magnitude as that in defined medium, however much lower P/2e−ratios are found during the subsequent period of slow growth. The P/2e−ratios for tetrathionate reduction in complex medium for both growth periods are lower than those in defined medium. Most
probably these results indicate that during this period growth and energy production are uncoupled. Under aerobic conditions
in complex medium a constant YO value of 32.2 g/atom O is found during a short period of the growth curve. Afterwards when the cell density increases a steady
decrease of YO is observed. 相似文献
9.
This study examined whether ‘Risnod2’ and ‘Risnod27’ non-nodulating mutants of pea (Pisum sativum L.) provided with increasing concentrations of nitrate could achieve a growth and nitrogen accumulation comparable to their
parental N2-fixing cv. Finale. In the cv. Finale, nodule number, nodule dry mass accumulation, total C2H2-reducing activity of nodulated roots (TAR) and estimated N2 fixation were considerably inhibited at 5.0 and 10.0 mM root medium NO3
− concentrations. In contrast a 0.63 mM level stimulated both the nodule dry mass and TAR. The cv. Finale N2-fixing plants grown on 0 to 2.5 mM NO3
− levels had higher shoot N concentrations than the Nod− mutants, but within the 5.0 to 10.0 mM levels the Nod− mutants approached or even overtopped the N concentration of the cv. Finale plants. Compared with a high positive correlation
found in the Nod− mutants, shoot N concentration in the cv. Finale was negatively correlated with the root medium NO3
− concentration. The pattern of nitrogen content in shoot dry mass was very similar to that seen in the shoot dry mass accumulation.
The Nod− mutants grown on the 5.0 and/or 10.0 mM NO3
− level had plant dry mass, shoot nitrogen concentration, shoot nitrogen content, and root/shoot dry mass ratio comparable
with those of the nodulating cv. Finale grown on the same nitrate levels. 相似文献
10.
Franco Zoccarato Lucia Cavallini Adolfo Alexandre 《Journal of bioenergetics and biomembranes》2009,41(4):387-393
Mitochondrial production of H2O2 is low with NAD substrates (glutamate/pyruvate, 3 and 2 mM) (G/P) and increases over ten times upon further addition of succinate,
with the formation of a sigmoidal curve (semimaximal value at 290 μM, maximal H2O2 production at 600 μM succinate). Malate counteracts rapidly the succinate induced increased H2O2 release and moves the succinate dependent H2O2 production curve to the right. Nitric oxide (NO) and carbon monoxide (CO) are cytochrome c oxidase inhibitors which increase
mitochondrial ROS production. Cyanide (CN−) was used to mimic NO and CO. In the presence of G/P and succinate (300 μM), CN− progressively increased the H2O2 release rate, starting at 1.5 μM. The succinate dependent H2O2 production curve was moved to the left by 30 μM CN−. The Vmax was little modified. We conclude that succinate is the controller of mitochondrial H2O2 production, modulated by malate and CN−. We propose that succinate promotes an interaction between Complex II and Complex I, which activates O2− production. 相似文献
11.
D. E. KOEPPE 《Physiologia plantarum》1972,27(1):89-94
The effects of juglone on the uptake of O2 by excised corn roots (Zea mays L., Wf9 cms- T × M14) and isolated corn mitochondria arc reported. The O2 uptake by excised corn roots, as measured by an O2 electrode, was inhibited more than 90% after a one-hour treatment of 500 μM juglone. Lesser inhibitions were observed with 50 μM and 250 μM juglone. In a KC1 reaction medium in the absence of inorganic phosphate (Pi), juglone stimulated the rate of O2 uptake by isolated mitochondria oxidizing NADH, succinate, or malate + pyruvate. In the presence of Pi, juglone concentrations of 3 μM and greater inhibited the state 3 oxidation rates of succinate and malate + pyruvate, lowered respiratory control and ADP/O ratios obtained from the oxidation of NADH, malate + pyruvate, or succinate, and reduced the coupled deposition of calcium phosphate within isolated mitochondria driven, by the oxidation of malate + pyruvate. The inhibition of state 3 O2 uptake by isolated mitochondria, an oxidative state in which electron transfer is coupled to ATP production, is seen to correlate with the inhibition affected by juglone when applied to tissues in vivo. 相似文献
12.
Wetlands are often highly effective nitrogen (N) sinks. In the Lake Waco Wetland (LWW), near Waco, Texas, USA, nitrate (NO3−) concentrations are reduced by more than 90% in the first 500 m downstream of the inflow, creating a distinct gradient in
NO3− concentration along the flow path of water. The relative importance of sediment denitrification (DNF), dissimilatory NO3− reduction to ammonium (DNRA), and N2 fixation were examined along the NO3− concentration gradient in the LWW. “Potential DNF” (hereafter potDNF) was observed in all months and ranged from 54 to 278 μmol N m−2 h−1. “Potential DNRA” (hereafter potDNRA) was observed only in summer months and ranged from 1.3 to 33 μmol N m−2 h−1. Net N2 flux ranged from 184 (net denitrification) to −270 (net N2 fixation) μmol N m−2 h−1. Nitrogen fixation was variable, ranging from 0 to 426 μmol N m−2 h−1, but high rates ranked among the highest reported for aquatic sediments. On average, summer potDNRA comprised only 5% (±2%
SE) of total NO3− loss through dissimilatory pathways, but was as high as 36% at one site where potDNF was consistently low. Potential DNRA
was higher in sediments with higher sediment oxygen demand (r
2 = 0.84), and was related to NO3− concentration in overlying water in one summer (r
2 = 0.81). Sediments were a NO3− sink and accounted for 50% of wetland NO3− removal (r
2 = 0.90). Sediments were an NH4+ source, but the wetland was often a net NH4+ sink. Although DNRA rates in freshwater wetlands may rival those observed in estuarine systems, the importance of DNRA in
freshwater sediments appears to be minor relative to DNF. Furthermore, sediment N2 fixation can be extremely high when NO3− in overlying water is consistently low. The data suggest that newly fixed N can support sustained N transformation processes
such as DNF and DNRA when surface water inorganic N supply rates are low. 相似文献
13.
Metabolism of ammonia (NH3) and hydroxylamine (NH2OH) by wild-type and a nitrite reductase (nirK) deficient mutant of Nitrosomonas europaea was investigated to clarify the role of NirK in the NH3 oxidation pathway. NirK-deficient N. europaea grew more slowly, consumed less NH3, had a lower rate of nitrite (NO2
−) production, and a significantly higher rate of nitrous oxide (N2O) production than the wild-type when incubated with NH3 under high O2 tension. In incubations with NH3 under low O2 tension, NirK-deficient N. europaea grew more slowly, but had only modest differences in NH3 oxidation and product formation rates relative to the wild-type. In contrast, the nirK mutant oxidized NH2OH to NO2
− at consistently slower rates than the wild-type, especially under low O2 tension, and lost a significant pool of NH2OH–N to products other than NO2
− and N2O. The rate of N2O production by the nirK mutant was ca. three times higher than the wild-type during hydrazine-dependent NO2
− reduction under both high and low O2 tension. Together, the results indicate that NirK activity supports growth of N. europaea by supporting the oxidation of NH3 to NO2
− via NH2OH, and stimulation of hydrazine-dependent NO2
− reduction by NirK-deficient N. europaea indicated the presence of an alternative, enzymatic pathway for N2O production. 相似文献
14.
Summary Short-term absorption experiments were conducted with intact barley (Hordeum vulgare L.) seedlings to observe the effects of the osmotic potential (Ψπ) and salt species on nitrate uptake andin vivo nitrate reduction. The experiments consisted of growing barley seedlings for 5 days in complete nutrient solutions salinized
to (Ψπ) levels of −0.6, −1.8, −3.0, −4.2, and −5.4 bars with NaCl, CaCl2 or Na2SO4. After the absorption period, the seedlings were separated into shoots and roots, weighed, then analyzed for NO3. The nutrient solutions were sampled for NO3 analysis each day immediately before renewing the solutions. The accumulative loss of NO3 from the solutions was considered to be uptake whereas NO3 reduction was the difference between uptake and seedling content. Lowering the (Ψπ) of the nutrient solutions resulted in decreased concentrations of NO3 in the plant, little or no effect (except at the lowest (Ψπ) level) on uptake, and increased nitrate reductase activity. Increased rates of NO3 reduction were in particular associated with the Cl concentration of the nutrient solution. 相似文献
15.
Flores A Nisola GM Cho E Gwon EM Kim H Lee C Park S Chung WJ 《Bioprocess and biosystems engineering》2007,30(3):197-205
The performance of enriched sludge augmented with the B21 strain of Alcaligenes defragrans was compared with that of enriched sludge, as well as with pure Alcaligenes defragrans B21, in the context of a sulfur-oxidizing denitrification (SOD) process. In synthetic wastewater treatment containing 100–1,000 mg
NO3−-N/L, the single strain-seeded system exhibited superior performance, featuring higher efficiency and a shorter startup period,
provided nitrate loading rate was less than 0.2 kg NO3−-N/m3 per day. At nitrate loading rate of more than 0.5 kg NO3−-N/m3 per day, the bioaugmented sludge system showed higher resistance to shock loading than two other systems. However, no advantage
of the bioaugmented system over the enriched sludge system without B21 strain was observed in overall efficiency of denitrification.
Both the bioaugmented sludge and enriched sludge systems obtained stable denitrification performance of more than 80% at nitrate
loading rate of up to 2 kg NO3−-N/m3 per day. 相似文献
16.
Dual isotope analyses indicate efficient processing of atmospheric nitrate by forested watersheds in the northeastern U.S. 总被引:1,自引:1,他引:0
Nitrogen from atmospheric deposition serves as the dominant source of new nitrogen to forested ecosystems in the northeastern
U.S. By combining isotopic data obtained using the denitrifier method, with chemical and hydrologic measurements we determined
the relative importance of sources and control mechanisms on nitrate (NO3
−) export from five forested watersheds in the Connecticut River watershed. Microbially produced NO3
− was the dominant source (82–100%) of NO3
− to the sampled streams as indicated by the δ15N and δ18O of NO3
−. Seasonal variations in the δ18O–NO3
− in streamwater are controlled by shifting hydrologic and temperature affects on biotic processing, resulting in a relative
increase in unprocessed NO3
− export during winter months. Mass balance estimates find that the unprocessed atmospherically derived NO3
− stream flux represents less than 3% of the atmospherically delivered wet NO3
− flux to the region. This suggests that despite chronically elevated nitrogen deposition these forests are not nitrogen saturated
and are retaining, removing, and reprocessing the vast majority of NO3
− delivered to them throughout the year. These results confirm previous work within Northeastern U.S. forests and extend observations
to watersheds not dominated by a snow-melt driven hydrology. In contrast to previous work, unprocessed atmospherically derived
NO3
− export is associated with the period of high recharge and low biotic activity as opposed to spring snowmelt and other large
runoff events. 相似文献
17.
Nitrosomonas eutropha, an obligately lithoautotrophic bacterium, was able to nitrify and denitrify simultaneously under anoxic conditions when
gaseous nitrogen dioxide (NO2) was supplemented to the atmosphere. In the presence of gaseous NO2, ammonia was oxidized, nitrite and nitric oxide (NO) were formed, and hydroxylamine occurred as an intermediate. Between
40 and 60% of the produced nitrite was denitrified to dinitrogen (N2). Nitrous oxide (N2O) was shown to be an intermediate of denitrification. Under an N2 atmosphere supplemented with 25 ppm NO2 and 300 ppm CO2, the amount of cell protein increased by 0.87 mg protein per mmol ammonia oxidized, and the cell number of N. eutropha increased by 5.8 × 109 cells per mmol ammonia oxidized. In addition, the ATP and NADH content increased by 4.3 μmol ATP (g protein)–1 and 6.3 μmol NADH (g protein)–1 and was about the same in both anaerobically and aerobically grown cells. Without NO2, the ATP content decreased by 0.7 μmol (g protein)–1, and the NADH content decreased by 1.2 μmol (g protein)–1. NO was shown to inhibit anaerobic ammonia oxidation.
Received: 9 October 1996 / Accepted: 5 December 1996 相似文献
18.
We assessed the effect of whole-stream nitrate enrichment on decomposition of three substrates differing in nutrient quality
(alder and oak leaves and balsa veneers) and associated fungi and invertebrates. During the 3-month nitrate enrichment of
a headwater stream in central Portugal, litter was incubated in the reference site (mean NO3-N 82 μg l−1) and four enriched sites along the nitrate gradient (214–983 μg NO3-N l−1). A similar decomposition experiment was also carried out in the same sites at ambient nutrient conditions the following
year (33–104 μg NO3-N l−1). Decomposition rates and sporulation of aquatic hyphomycetes associated with litter were determined in both experiments,
whereas N and P content of litter, associated fungal biomass and invertebrates were followed only during the nitrate addition
experiment. Nitrate enrichment stimulated decomposition of oak leaves and balsa veneers, fungal biomass accrual on alder leaves
and balsa veneers and sporulation of aquatic hyphomycetes on all substrates. Nitrate concentration in stream water showed
a strong asymptotic relationship (Michaelis–Menten-type saturation model) with temperature-adjusted decomposition rates and
percentage initial litter mass converted into aquatic hyphomycete conidia for all substrates. Fungal communities did not differ
significantly among sites but some species showed substrate preferences. Nevertheless, certain species were sensitive to nitrogen
concentration in water by increasing or decreasing their sporulation rate accordingly. N and P content of litter and abundances
or richness of litter-associated invertebrates were not affected by nitrate addition. It appears that microbial nitrogen demands
can be met at relatively low levels of dissolved nitrate, suggesting that even minor increases in nitrogen in streams due
to, e.g., anthropogenic eutrophication may lead to significant shifts in microbial dynamics and ecosystem functioning.
Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at . 相似文献
19.
Seaweeds growing in the intertidal zone are exposed to fluctuating nitrate and ultraviolet radiation (UVR) levels. While it
has been shown that elevated UVR levels and the decrease of nitrate concentration can reduce photosynthetic levels in seaweeds,
less is known about the combined effect of nitrate levels and UVR on metabolism and photoprotection mechanisms of intertidal
species. Consequently, the objective of this study was to evaluate the effect of nitrate concentration and UVR treatments
on photosynthesis, respiration, nitrate reductase activity and phenolic compound levels of Ulva rigida (Chlorophyta). There was a two- to threefold increase in maximal gross photosynthesis (GPmax) and respiration rates, as nitrate increased from 0 to 50 μM NO3−. Similarly, nitrate reductase activity increased linearly from low values in algae incubated at 0 μM NO3 to high values in tissue incubated at 50 μM NO3−. Phenolic compounds in the tissue of U. rigida increased approximately 60% under 50 μM NO3− relative to those incubated at 0 μM NO3−. Algae exposed to UVR (8 h) showed a significant decrease in the effective quantum yield and respiration, however, no effect
was observed in the phenolic compounds levels. Full recovery of effective quantum yield was observed after U. rigida was transferred for 48 h to low PAR. Nitrate reductase also decreased after an 8-h UVR exposure, but no differences were
observed among the nitrate treatments. This study shows that high nitrate levels reduced the negative effect of UVR on the
effective quantum yield and increased the recovery of key metabolic enzymes. It is possible that the increase of phenolic
compounds in the thallus of U. rigida under high nitrate levels provide a photoprotective mechanism when exposed to high UV levels during low tides. 相似文献
20.
Luisa Maia Rui O. Duarte Ana Ponces-Freire José J. G. Moura Lurdes Mira 《Journal of biological inorganic chemistry》2007,12(6):777-787
To characterise the NADH oxidase activity of both xanthine dehydrogenase (XD) and xanthine oxidase (XO) forms of rat liver
xanthine oxidoreductase (XOR) and to evaluate the potential role of this mammalian enzyme as an O2
•− source, kinetics and electron paramagnetic resonance (EPR) spectroscopic studies were performed. A steady-state kinetics
study of XD showed that it catalyses NADH oxidation, leading to the formation of one O2
•− molecule and half a H2O2 molecule per NADH molecule, at rates 3 times those observed for XO (29.2 ± 1.6 and 9.38 ± 0.31 min−1, respectively). EPR spectra of NADH-reduced XD and XO were qualitatively similar, but they were quantitatively quite different.
While NADH efficiently reduced XD, only a great excess of NADH reduced XO. In agreement with reductive titration data, the
XD specificity constant for NADH (8.73 ± 1.36 μM−1 min−1) was found to be higher than that of the XO specificity constant (1.07 ± 0.09 μM−1 min−1). It was confirmed that, for the reducing substrate xanthine, rat liver XD is also a better O2
•− source than XO. These data show that the dehydrogenase form of liver XOR is, thus, intrinsically more efficient at generating
O2
•− than the oxidase form, independently of the reducing substrate. Most importantly, for comparative purposes, human liver XO
activity towards NADH oxidation was also studied, and the kinetics parameters obtained were found to be very similar to those
of the XO form of rat liver XOR, foreseeing potential applications of rat liver XOR as a model of the human liver enzyme. 相似文献