Different subtypes of opioid receptors (OR) were activated in rats in vivo to study the activation effect on the heart’s resistance to ischemia and reperfusion. It has been established that administration of deltorphin II, a selective δ2-OR agonist, lowered the infarct size/area at risk index (IS/AAR) by 23%. Naltrexone, naloxone methiodide (an OR inhibitor not penetrating the blood-brain barrier (BBB)), and naltriben (δ2-antagonist) eliminated the cardioprotective effect of deltorphin II, while BNTX (a δ1-antagonist) produced no effect on the cardioprotective action of the δ2-agonist. The infarct-reducing effect of deltorphin II was eliminated by administration of chelerythrine (a protein kinase C (PKC) inhibitor), glibenclamide (a KATP-channels inhibitor), and 5-hydroxydecanoate (a mitochondrial KATP-channel blocker). Administration of other opioids did not reduce the IS/AAR index. It has been established that all the deltorphins manifest antiarrhythmic potency. Other opioids do not produce any effect on the incidence of arrhythmia occurrences. The antiarrhythmic effect of deltorphin II was eliminated by preliminary administration of naltrexone, naloxone methiodide, and naltriben, but BNTX did not affect the δ2-agonist’s anti-arrhythmic effect. The preliminary administration of chelerythrine, a PKC inhibitor, eliminated the δ2 agonist’s antiarrhythmic action. However, glibenclamide and 5-hydroxydecanoate did not alter the antiarrhythmic effect by deltorphin II. Therefore, activation of the peripheral δ2-ORs reduces the infarct size and prevents the onset of arrhythmias. The antiarrhythmic effect of the δ2-OR stimulation is mediated by activating PKC and opening the mitochondrial KATP-channels. PKC participates in the antiarrhythmic effect of the δ2-OR activation, but this effect does not depend on the condition of KATP-channels. 相似文献
An extension to HN(CO-α/β-N,Cα-J)-TROSY (Permi and Annila in J Biomol NMR 16:221–227, 2000) is proposed that permits the simultaneous determination of the four coupling constants 1JN′(i)Cα(i), 2JHN(i)Cα(i), 2JCα(i−1)N′(i), and 3JCα(i−1)HN(i) in 15N,13C-labeled proteins. Contrasting the original scheme, in which two separate subspectra exhibit the 2JCαN′ coupling as inphase and antiphase splitting (IPAP), we here record four subspectra that exhibit all combinations of inphase
and antiphase splittings possible with respect to both 2JCαN′ and 1JN′Cα (DIPAP). Complementary sign patterns in the different spectrum constituents overdetermine the coupling constants which can
thus be extracted at higher accuracy than is possible with the original experiment. Fully exploiting data redundance, simultaneous
2D lineshape fitting of the E.COSY multiplet tilts in all four subspectra provides all coupling constants at ultimate precision.
Cross-correlation and differential-relaxation effects were taken into account in the evaluation procedure. By applying a four-point
Fourier transform, the set of spectra is reversibly interconverted between DIPAP and spin-state representations. Methods are
exemplified using proteins of various size. 相似文献
Oestrogens and 1α,25(OH)2-vitamin D3 (1,25-D3) are steroids that can provide effects by binding to their receptors localised in the cytoplasm and in the nucleus or the plasma membrane respectively inducing genomic and non-genomic effects. As confirmed notably by invalidation of the genes, coding for their receptors as tested with mice with in vivo and in vitro treatments, oestrogens and 1,25-D3 are regulators of spermatogenesis. Moreover, some functions of ejaculated spermatozoa as viability, DNA integrity, motility, capacitation, acrosome reaction and fertilizing ability are targets for these hormones. The studies conducted on their mechanisms of action, even though not completely elicited, have allowed the demonstration of putative interactions between their signalling pathways that are worth examining more closely. The present review focuses on the elements regulated by oestrogens and 1,25-D3 in the testis and spermatozoa as well as the interactions between the signalling pathways of both hormones. 相似文献
The nature of M–M bonding and aromaticity of [M2(NHCHNH)3]2(μ-E)2 (E?=?O, S; M?=?Nb, Mo, Tc, Ru, Rh) was investigated using atoms in molecules (AIM) theory, electron localization function (ELF), natural bond orbital (NBO) and molecular orbital analysis. These analyses led to the following main conclusions: in [M2(NHCHNH)3]2(μ-E)2 (E?=?O, S; M?=?Nb, Mo, Tc, Ru, Rh), the Nb–Nb, Ru–Ru, and Rh–Rh bonds belong to “metallic” bonds, whereas Mo–Mo and Tc–Tc drifted toward the “dative” side; all these bonds are partially covalent in character. The Nb–Nb, Mo–Mo, and Tc–Tc bonds are stronger than Ru–Ru and Rh–Rh bonds. The M–M bonds in [M2(NHCHNH)3]2(μ-S)2 are stronger than those in [M2(NHCHNH)3]2(μ-O)2 for M?=?Nb, Mo, Tc, and Ru. The NICS(1)ZZ values show that all of the studied molecules, except [Ru2(NHCHNH)3]2(μ-O)2, are aromaticity molecules. O-bridged compounds have more aromaticity than S-bridged compounds.
Graphical AbstractLeft Molecular graph, and right electron localization function (ELF) isosurface of [M2(NHCHNH)3]2(μ-E)2(E?=?O, S; M?=?Nb, Mo, Tc, Ru, Rh)
The cystine/glutamate exchanger (antiporter xc−) is a membrane transporter involved in the uptake of cystine, the rate-limiting amino acid in the synthesis of glutathione.
Recent studies suggest that the antiporter plays a role in the slow oxidative excitotoxity and in the pathological effects
of β-N-oxalylamino-l-alanine, the molecule responsible for neurolathyrism, a neurotoxic upper motor neuron disease. The mouse cystine/glutamate
exchanger has been cloned and showed to be composed of two distinct proteins, one of which being a novel protein, named xCT,
of 502 amino acids and 12 putative trans-membrane domains. We have generated and purified a polyclonal antibody to mouse xCT
and studied its expression in rat brain and in different cultured cells (astrocytes, fibroblasts and neurons) using Western
blot and immunocytochemical techniques. Expression of xCT was also studied in rat brain and muscle at different developmental
stages. Parallel experiments were carried out with antibodies to the heavy chain of 4F2 surface antigen, the non-specific
subunit of the antiporter xc−. xCT antibody detected in all cell and tissue extracts a specific band of about 40 kDa. Subcellular fractionation demonstrated
that xCT is concentrated mainly in the microsomal-mitochondrial fraction, in accord with its structure as transmembrane protein.
Immunocytochemical analysis showed a strong staining in all cells examined, included neurons. Furthermore, both xCT and the
heavy chain of 4F2 surface antigen increased in the brain during development, reaching the highest expression in adulthood.
The study of the expression and developmental profile of xCT represents a first step towards a better characterization of
its biochemical properties and function, which in turn may help to understand the relative contribution of the xc− antiporter in the pathogenesis of certain neurodegenerative diseases. 相似文献
Lipase r27RCL is a 296-residue, 33 kDa monomeric enzyme with high ester hydrolysis activity, which has significant applications in the baking, paper and leather industries. The lipase gene proRCL from Rhizopus microsporus var. chinensis (also Rhizopus chinensis) CCTCC M201021 was cloned as a fusion construct C-terminal to a maltose-binding protein (MBP) tag, and expressed as MBP-proRCL in an Escherichia coli BL21 trxB (DE3) expression system with uniform 2H,13C,15N-enrichment and Ile-δ1, Leu, and Val 13CH3 methyl labeling. The fusion protein was hydrolyzed by Kex2 protease at the recognition site Lys-Arg between residues ?29 and ?28 of the prosequence, producing the enzyme form called r27RCL. Here we report extensive backbone 1H, 15N, and 13C, as well as Ile-δ1, Leu, and Val side chain methyl, NMR resonance assignments for r27RCL. 相似文献
Small lakes in northern latitudes represent a significant source of CH4 to the atmosphere that is predicted to increase with warming in the Arctic. Yet, whole-lake CH4 budgets are lacking as are measurements of δ13C-CH4 and δ2H-CH4. In this study, we quantify spatial variability of diffusive and ebullitive fluxes of CH4 and corresponding δ13C-CH4 and δ2H-CH4 in a small, Arctic lake system with fringing wetland in southwestern Greenland during summer. Net CH4 flux was highly variable, ranging from an average flux of 7 mg CH4 m?2 d?1 in the deep-water zone to 154 mg CH4 m?2 d?1 along the lake margin. Diffusive flux accounted for ~8.5 % of mean net CH4 flux, with plant-mediated and ebullitive flux accounting for the balance of the total net flux. Methane content of emitted ebullition was low (mean ± SD 10 ± 17 %) compared to previous studies from boreal lakes and wetlands. Isotopic composition of net CH4 emissions varied widely throughout the system, with δ13C-CH4 ranging from ?66.2 to ?55.5 ‰, and δ2H-CH4 ranging from ?345 to ?258 ‰. Carbon isotope composition of CH4 in ebullitive flux showed wider variation compared to net flux, ranging from ?69.2 to ?49.2 ‰. Dissolved CH4 concentrations were highest in the sediment and decreased up the water column. Higher concentrations of CH4 in the hypoxic deep water coincided with decreasing dissolved O2 concentrations, while methanotrophic oxidation dominated in the epilimnion based upon decreasing concentrations and increasing values of δ13C-CH4 and δ2H-CH4. The most depleted 13C- and 2H-isotopic values were observed in profundal bottom waters and in subsurface profundal sediments. Based upon paired δ13C and δ2H observations of CH4, acetate fermentation was likely the dominant production pathway throughout the system. However, isotopic ratios of CH4 in deeper sediments were consistent with mixing/transition between CH4 production pathways, indicating a higher contribution of the CO2 reduction pathway. The large spatial variability in fluxes of CH4 and in isotopic composition of CH4 throughout a single lake system indicates that the underlying mechanisms controlling CH4 cycling (production, consumption and transport) are spatially heterogeneous. Net flux along the lake margin dominated whole-lake flux, suggesting the nearshore littoral area dominates CH4 emissions in these systems. Future studies of whole-lake CH4 budgets should consider this significant spatial heterogeneity. 相似文献
Nitrate dual stable isotopes (δ15N and δ18O of NO3?) have proven to be a powerful technique to elucidate nitrogen (N) cycling pathways in aquatic systems. We applied this technique for the first time in the pelagic zone of a small temperate meso-eutrophic lake to identify the dominant N cycling pathways, and their spatial and temporal variability. We measured the lake NO3? δ15N and δ18O signatures over an annual cycle and compared them to that of the watershed. Both δ15N and δ18O of NO3? in the lake increased during summer relative to the inputs. Relationships between lake NO3? isotopic composition and concentrations were different across thermal strata with an apparent isotope effect in the epilimnion of 15εepi = 4.6‰ and 18εepi = 10.9‰. We found a strong deviation of the lake NO3? δ18O and δ15N from the expected 1:1 line for assimilation (slope = 1.73) suggesting that nitrification was co-occurring. We estimated that nitrification could support between 5 and 30% of nitrate-based production during the growing season, but was negligible in early spring and fall, and probably more dominant under ice. We showed that the technique is promising to study N processes at the ecosystem scale in shallow lakes, particularly during winter. Our results suggest that recycled NO3? could support primary productivity and influence phytoplankton composition in the surface waters of small lakes. 相似文献
In the recent past, we have observed a possible role of 10398A and 16189C mtDNA and PGC1α p.Thr394Thr (rs2970847) and p.Gly482Ser (rs8192673) variant genotypes providing susceptibility/protection against type 2
diabetes mellitus (T2DM) in two North Indian population groups. These initial observations encouraged us to look at the candidate
genes in combination with –866G/A (rs659366) polymorphism in uncoupling protein 2 (UCP2) in a single study of a relatively large sample size, constituted of both the cohorts, to unravel an interesting outcome
of an additive interaction in-between the studied genes. In a total of 1,686 individuals (762 cases and 924 controls) belonging
to Indo-European linguistic group from North India, a comparison of risk genotype combinations of: UCP2–866GG, mtDNA 10398A and PGC1α p.Thr394Thr or p.Gly482Ser against the protective genotypes: UCP2–866XA, mtDNA 10398G and PGC1α p.Thr394Thr (nominal P value = 1.75 × 10−14, Odds ratio, OR = 5.29, 3.40–8.22 at 95% CI) or PGC1α p.Gly482Ser (nominal p value = 4.42 × 10−24, OR = 8.59, 5.53–13.35 at 95% CI), showed a highly significant difference and increased ORs. In a complex disease, it is
always encouraging to find an additive interaction of multiple small effects of the studied candidate gene variations.
An erratum to this article is available at . 相似文献
Large variations in leaf δ15N in Bornean tropical rainforest trees may indicate that various tropical species have species-specific strategy for nitrogen uptake under low soil nutrient conditions, including root symbiotic microorganisms such as ectomycorrhiza.
Abstract
Lowland tropical rainforests in Southeast Asia are characterized by high species diversity despite limited soil nutrient conditions. The plant nitrogen isotope ratio (δ15N) reflects plant uptake of soil nitrogen. We analyzed δ15N values and nitrogen content (N %) in leaves and roots of 108 woody species with different types of symbiotic microorganisms, of different life forms (emergent, canopy, sub-canopy, understory, and canopy gap species), and from different families in a Bornean lowland dipterocarp forest to gain more insight into the diversity of nitrogen uptake strategy in the rhizosphere. Leaf δ15N values in the species studied varied largely from ?7.2 to 5.0 ‰, which is comparable to the values of known Asian trees including temperate, sub-tropical, and tropical mountain forests. Leaf δ15N also varied significantly among both life forms and families, though the phylogenetically independent contrast (PIC) relationships were not statistically significant among life form, family, and symbiotic types. Some families showed specific leaf δ15N values; Dipterocarpaceae, the dominant family in the canopy layer with symbiotic ectomycorrhiza in Southeast Asia, had small intraspecific variation and higher leaf δ15N values (0.03 ‰) compared with species exhibiting arbuscular mycorrhiza, whereas several families such as Burseraceae, Euphorbiaceae, and Myrtaceae showed large interspecific variation in leaf δ15N (e.g., from ?7.2 to 5.0 ‰ in Euphorbiaceae). These variations suggest that tropical species may have family- or species-specific strategy, such as root symbiotic microorganisms, for nitrogen uptake under low-nutrient conditions in tropical rainforests in Southeast Asia.
Most skin pathologies are characterized by unbalanced synthesis of major histocompatability complex II (MHC-II) proteins.
Healthy skin keratinocytes simultaneously produce large amounts of MHC-II and regeneration-supporting proteins, e.g. erythropoietin
(EPO), EPO receptor (EPOR), glutamine synthetase (GS) and metallothionein (MT). To investigate the level of regeneration-supporting
proteins in the skin during misbalanced production of MHC-II, skin sections from nonobese diabetic/severe combined immunodeficient
(NOD/SCID)/γcnull and or Foxn1 nu/nu mice which are a priory known to under- and over-express MHC II, respectively, were used. Double immunofluorescence
analysis of NOD/SCID/γcnull skin sections showed striking decrease in expression of MHC-II, EPO, GS and MT. In Foxn1 nu/nu mouse skin, GS was strongly
expressed in epidermis and in hair follicles (HF), which lacked EPO. In nude mouse skin EPO and MHC-II were over-expressed
in dermal fibroblasts and they were completely absent from cortex, channel, medulla and keratinocytes surrounding the HF,
suggest a role for EPO in health and pathology of hair follicle. The level of expression of EPO and GS in both mutant mice
was confirmed by results of Western blot analyses. Strong immunoresponsiveness of EPOR in the hair channels of NOD/SCID/γcnull mouse skin suggests increased requirements of skin cells for EPO and possible benefits of exogenous EPO application during
disorders of immune system accompanied by loss MHC-II in skin cells. 相似文献
The taxonomic significance of the main morphological features of the 25 species allocated to Andrya Railliet, 1893 and Paranoplocephala Lühe, 1910 is re-evaluated in the light of the recent molecular phylogenetic hypotheses for anoplocephaline cestodes. The present analysis
and the existing phylogenetic data suggest that the structure and complexity of the early uterus are not, as previously assumed,
the main phylogenetic or systematic determinants for anoplocephaline cestodes. Instead, the position of the early uterus with
respect to other organs, combined with the morphology of the female genitalia, appear to allow a fairly straightforward discrimination
of the three genera recognised here, without contradicting current phylogenetic hypotheses. A new genus, Neandrya n. g., is proposed for N. cuniculi (Blanchard, 1891) n. comb. (previously in Andrya), amended diagnoses are provided for Andrya and Paranoplocephala and a diagnostic key to these three genera is presented. 相似文献
We report on the transformation and expression in sugar beet (Beta vulgaris) hairy roots of a Nicotiana alata NaPI gene encoding a serine proteinase inhibitor (PI) that has been shown to effectively reduce the population of a number of
insect pests. Using in-gel analysis, two PI protein activities were detected at approximately 24- and/or 28-kDa in hairy roots
generated via Agrobacterium rhizogenes-mediated gene transfer. Immunoblot analysis revealed the presence of the expected ~40 kDa precursor, and in some transformants,
a ~20 kDa processing intermediate and the mature 6-kDa PIs. In general, processing of the precursor in the clonal lines was
reduced or not detected. The reduced efficiency of post-translational processing of the N. alata PI precursor may be attributed to modification and/or altered folding of the recombinant protein or distinct post-translational
machinery functioning in sugar beet hairy roots and Nicotiana.
Disclaimer: Mention and/or use of a commercial or proprietary product to the exclusion of others does not constitute endorsement
by the USDA. 相似文献
Interleukin-36α (IL-36α) is a recently characterised member of the interleukin-1 superfamily. It is involved in the pathogenesis of inflammatory arthritis in one third of psoriasis patients. By binding of IL-36α to its receptor IL-36R via the NF-κB pathway other cytokines involved in inflammatory and apoptotic cascade are activated. The efficacy of complex formation is controlled by N-terminal processing. To obtain a more detailed view on the structure function relationship we performed a heteronuclear multidimensional NMR investigation and here report the 1H, 13C, and 15N resonance assignments for the backbone and side chain nuclei of the pro-inflammatory cytokine interleukin-36α. 相似文献
The interaction of the diastereomeric complexes Λ-[Ru(bpy)2(m-GHK)]Cl2 and Δ-[Ru(bpy)2(m-GHK)]Cl2 (bpy is 2,2′-bipyridine, GHK is glycine–l-histidine–l-lysine) with the deoxynucleotide duplex d(5′-CGCGATCGCG)2 was studied by means of 1H NMR spectroscopy. At a Δ-isomer to DNA ratio of 1:1, significant shifts for the metal complex are observed, whereas there is negligible effect on
the oligonucleotide protons and only one intermolecular nuclear Overhauser effect (NOE) is present at the 2D nuclear Overhauser
enhancement spectroscopy spectrum. The 1Η NMR spectrum at ratio 2:1 is characterized by a slight shift for the Δ-isomer’s bpy aromatic protons as well as significant shifts for the decanucleotide G4 H1′ and Η2″, A5 H2, G10 H1′, T6 NH and G2 NH protons. Furthermore, at ratio 2:1, 11 intermolecular NOEs are observed. The majority of the NOEs involve the sugar Η2′
and Η2″ protons sited in the major groove of the decanucleotide. Increasing the Δ-isomer to d(CGCGATCGCG)2 ratio to 5:1 results in noteworthy spectral changes. The Δ-isomer’s proton shifts are reduced, whereas significant shifts are observed for the decanucleotide protons, especially the
sugar protons, as well as for the exchangeable protons. Interaction is characterized by the presence of only one intermolecular
NOE. Furthermore, there is significant broadening of the imino proton signals as the ratio of the Δ-isomer to DΝΑ increases, which is attributed to the opening of the two strands of the duplex. The Λ-isomer, on the other hand, approaches the minor groove of the oligonucleotide and interacts only weakly, possibly by electrostatic
interactions. Photocleavage studies were also conducted with the plasmid pUC19 and a 158-bp restriction fragment, showing
that both diastereomers cleave DNA with similar efficiency, attacking mainly the guanines of the sequence probably by generating
active oxygen species.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.
An erratum to this article can be found at 相似文献
Among various types of ionizing radiation, the beta emitter radionuclides are involved in many sectors of human activity, such as nuclear medicine, nuclear industries and biomedicine, with a consequently increased risk of accidental, occupational or therapeutic exposure. Despite their recognized importance, there is little information about the effect of beta particles at the cellular level when compared to other types of ionizing radiation. Thus, the objective of the present study was to evaluate the genotoxic and cytotoxic effects of 90Sr/90Y—a pure, highly energetic beta source—on Chinese hamster ovary (CHO) cells and to compare them with data obtained with 60Co. CHO cells irradiated with different doses of 60Co (0.34 Gy min–1) and 90Sr/90Y (0.23 Gy min–1) were processed for analysis of clonogenic death, induction of micronuclei (MN) and interphase death. The survival curves obtained for both types of radiation were fitted by the exponential quadratic model and were found to be similar. Also, the cytogenetic results showed similar frequencies of radio-induced MN between gamma and beta radiations and the MN distribution pattern among cells did not follow the expected Poisson probability pattern. The relative variance values were significantly higher in cells irradiated with 90Sr/90Y than with 60Co in all exposure doses. The irradiated cells showed more necrotic cells 72 h and 96 h after exposure to beta than to gamma radiation. In general, the 90Sr/90Y -radiation was more damaging than 60Co -rays. The data obtained also demonstrated the need to use several parameters for a better estimate of cellular sensitivity to the action of genotoxic agents, which would be important in terms of radiobiology, oncology and therapeutics. 相似文献
Leaves from several desert and woodland species, including gymnosperms and angiosperms with both C3 and C4 physiology, were analyzed to detect trends in '13Cleaf with elevation and slope aspect along two transects in southeastern Utah and south-central New Mexico, USA. The main difference between the two transects is the steeper elevational gradient for mean annual and summer precipitation in the southern transect. For any given species, we found that isotopic differences between individual plants growing at the same site commonly equal differences measured for plants along the entire altitudinal gradient. In C3 plants, '13Cleaf values become slightly enriched at the lowest elevations, the opposite of trends identified in more humid regions. Apparently, increasing water-use efficiency with drought stress offsets the influence of other biotic and abiotic factors that operate to decrease isotopic discrimination with elevation. For some species shared by the two transects (e.g., Pinus edulis and Cercocarpus montanus), '13Cleaf values are dramatically depleted at sites that receive more than 550 mm mean annual precipitation, roughly the boundary (pedalfer-pedocal) at which soils commonly fill to field capacity in summer and carbonates are leached. We hypothesize that, in summer-wet areas, this may represent the boundary at which drought stress overtakes other factors in determining the sign of '13Cleaf with elevation. The opposition of isotopic trends with elevation in arid versus humid regions cautions against standard correction for elevation in comparative studies of '13Cleaf. 相似文献
Recent studies suggest that the direction and magnitude of changes in soil organic carbon (soil C) pools following forest-to-pasture conversion in the tropics are dependent upon initial soil conditions and local factors (e.g. pre-conversion soil C content, soil texture, vegetation productivity, and management practices). The goal of this study was to understand how landscape-scale variation in soil-forming factors influenced the response of soil C pools to forest clearing and pasture establishment in northeastern Costa Rica. We measured soil C and its stable isotopic composition in 24 paired pasture and reference forest sites distributed over large gradients of edaphic characteristics and slope throughout a 1400 km2 region. We used the large difference in stable C isotopic signatures of C3 vegetation (rain forest) versus C4 vegetation (pasture grasses) as a tracer of soil C dynamics. Soil C pools to 30 cm depth ranged from 26% lower to 23% higher in pastures compared to paired forests. The presence of non-crystalline clays and percent slope explained between 27 and 37% of the variation in the direction and magnitude of the changes in soil C storage following pasture establishment. Stable carbon isotopes (13C) in the top soil (0–10 cm) showed a rapid incorporation of pasture-derived C following pasture establishment, but the vegetation in these pastures never became pure C4 communities. The amount of forest-derived soil C in pasture topsoils (0–10 cm) was negatively correlated to both pasture age and the concentrations of non-crystalline iron oxides. Together these results imply that site factors such as soil mineralogy are an important control over soil C storage and turnover in this region. 相似文献
Two chimeric genes, XynA-Bs-Glu-1 and XynA-Bs-Glu-2, encoding Aspergillus sulphureus β-xylanase (XynA, 26 kDa) and Bacillus subtilis β-1,3-1,4-glucanase (Bs-Glu, 30 kDa), were constructed via in-fusion by different linkers and expressed successfully in Pichia pastoris. The fusion protein (50 kDa) exhibited both β-xylanase and β-1,3-1,4-glucanase activities. Compared with parental enzymes, the moiety activities were decreased in fermentation supernatants. Parental XynA and Bs-Glu were superior to corresponding moieties in each fusion enzymes because of lower Kn higher kcat. Despite some variations, common optima were generally 50°C and pH 3.4 for the XynA moiety and parent, and 40°C and pH 6.4 for the Bs-Glu counterparts. Thus, the fusion enzyme XynA-Bs-Glu-1 and XynA-Bs-Glu-2 were bifunctional. 相似文献