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1.
It has been suggested that the karyotype of the marsupials derived from a low diploid number (2n = 14) which originated, through
fissions of biarmed chromosomes, the karyotypes with a higher 2n. The telomeric sequence (T2AG3)nwas in situhybridized to the chromosomes of Gracilinanus microtarsusand G. emiliae, Micoureus demeraraeand Marmosa murina, species with 2n = 14, in Monodelphissp., M. domestica, M. kunsiand M. brevicaudatawith 2n = 18, and in Lutreolina crassicaudata, Didelphis albiventris, Chironectes minimus, Philander opossumand P. frenata, all of them with 2n = 22. The probe hybridization occurred in the telomeric regions of both arms, short and long, of all
chromosomes of the complement of all individuals of all species analysed. However, in some pairs of the karyotypes of Gracilinanus microtarsusand Micoureus demerarae(with 2n = 14), and in Monodelphissp., M. domestica, M. kunsiand M. brevicaudata(2n = 18) ectopic signs of hybridization were detected proximal to the centromeres, suggesting the retention of this telomeric
sequence in the centromeric regions of some chromosomes of these species. Based on these results, it is proposed that the
karyotype of marsupials evolved from a 2n = 22 to a 2n = 14, by means of chromosomal fusions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Comparative cytogenetic studies were carried out on Apareiodon affinis from an important hydrographic system at South America, the Paraná river basin. Two distant regions were chosen, which were
separated by Guaíra Falls (formerly Sete Quedas); the region in the upper part of the hydrographic basin is called Upper Paraná
(Brazil), whereas and the other in the lower part is called Lower Paraná (Argentina). Individuals from Upper Paraná have diploid
numbers of 2n = 54 (NF = 108) for males and 2n = 55 (NF = 110) for females, showing female heterogamety with a ZZ/ZW1W2 multiple sex chromosomes system that is endemic for the region. In different localities at Lower Paraná, the specimens presented
diploid number of 2n = 54 for both sexes, without any sex chromosomes heteromorphism. However, they have an accentuated polymorphism characterized
by variation in number of acrocentric chromosomes, constituting something new for family Parodontidae. The most likely hypothesis
to explain the origin of such polymorphism is based on successive pericentric inversions giving rise to acrocentric chromosomes.
Thus, it was possible to detect 10 cytotypes along the Lower Paraná basin. Such chromosomal variations possibly are the consequence
of an adaptative process. Our data probably indicate the occurrence of distinct species in each region that share the same
denomination.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
3.
Smirnova IA Zaslavsky D Fee JA Gennis RB Brzezinski P 《Journal of bioenergetics and biomembranes》2008,40(4):281-287
The ba
3-type cytochrome c oxidase from Thermus thermophilus is phylogenetically very distant from the aa
3–type cytochrome c oxidases. Nevertheless, both types of oxidases have the same number of redox-active metal sites and the reduction of O2 to water is catalysed at a haem a
3-CuB catalytic site. The three-dimensional structure of the ba
3 oxidase reveals three possible proton-conducting pathways showing very low homology compared to those of the mitochondrial,
Rhodobacter sphaeroides and Paracoccus denitrificans aa
3 oxidases. In this study we investigated the oxidative part of the catalytic cycle of the ba
3
-cytochrome c oxidase using the flow-flash method. After flash-induced dissociation of CO from the fully reduced enzyme in the presence
of oxygen we observed rapid oxidation of cytochrome b (k ≅ 6.8 × 104 s−1) and formation of the peroxy (PR) intermediate. In the next step a proton was taken up from solution with a rate constant of ~1.7 × 104 s−1, associated with formation of the ferryl (F) intermediate, simultaneous with transient reduction of haem b. Finally, the enzyme was oxidized with a rate constant of ~1,100 s−1, accompanied by additional proton uptake. The total proton uptake stoichiometry in the oxidative part of the catalytic cycle
was ~1.5 protons per enzyme molecule. The results support the earlier proposal that the PR and F intermediate spectra are similar (Siletsky et al. Biochim Biophys Acta 1767:138, 2007) and show that even though the architecture of the proton-conducting pathways is different in the ba
3 oxidases, the proton-uptake reactions occur over the same time scales as in the aa
3-type oxidases.
Smirnova and Zaslavsky contributed equally to the work described in this paper. 相似文献
4.
Based on new information on floral structures, seedling, fruit, seed, root, and leaflet characters, Phaseolus dasycarpus is re-described and illustrated. Its chromosome number was determined as 2n
= 22, with metacentric and submetacentric chromosomes, and karyotype formula of 9m + 2sm. Previous phylogenetic analyses of
ITS and trnK sequence data, and those obtained in the present study, show P. dasycarpus to be aligned within section Pedicellati.
Resumen Con nueva información de estructuras florales, plántulas, frutos, semillas, raíz y folíolos, se redescribe e ilustra a Phaseolus dasycarpus. Se determina el número cromosómico 2n = 22, con cromosomas metacéntricos y submetacéntricos y fórmula cariotípica = 9m + 2sm. Análisis filogenéticos previos con secuencias de ITS y trnK y los resultados obtenidos en el presente estudio, establecen a P. dasycarpus en la sección Pedicellati.相似文献
5.
Ono EY Fungaro MH Sofia SH Figueira EL Gerage AC Ichinoe M Sugiura Y Ueno Y Hirooka EY 《Mycopathologia》2004,158(4):451-455
Eleven feed samples associated with six animal (horse and poultry) intoxication outbreaks (1991) in the state of Paraná, Brazil,
were evaluated for fungal and fumonisin contamination. In order to estimate the␣trend of livestock intoxication, fumonisin
contamination was monitored in corn produced both at the commercial level (1991, 1995 crop), and in an experimental field
at a local Agronomy Institute (1997 crop). The total mould count in the feed samples ranged from 2.9 × 103 to 1.9 × 107 CFU/g, with Fusarium verticillioides as the predominant species, at a high count of 2.4 × 104–6.5 × 105 CFU/g. Fumonisins (FB1 + FB2) were detected in all corn-based feed samples at levels ranging from 2.89 to 14.54 μg/g. All 27 Northern corn samples (1991 crop) were contaminated with fumonisins at levels ranging from 2.32 to 16.64 μg/g. Twenty-six (96.3%) out of 27 corn samples from the Central-Southern region (1995 crop) were positive for fumonisins (FB1+FB2), with the range of 0.07–3.66 μg/g, while all 37 Northern samples (1995 crop) were contaminated with fumonisins ranging from 0.57 to 9.97 μg/g. Twenty-one out of 37 corn samples from the Northern region (1997 crop) were positive for fumonisins, but at low level
(range of 0.05–2.67 μg/g). The results showed a decreasing trend in fumonisin contamination over the years. Nowadays animal intoxication outbreaks
rarely occur in this State, as both animal producers and feed industries have become conscious about monitoring of corn and
other raw materials at the quality control level. 相似文献
6.
To estimate the age and growth of dominant lanternfishes in the Kuroshio–Oyashio Transition Zone, we examined the sagittal
otolith microstructure of Symbolophorus californiensis (n = 30) and Ceratoscopelus warmingii (n = 93) collected from the western North Pacific during 1997–2003. Age of S. californiensis ranged from 81 to 541 days corresponding to postmetamorphosis stage (juveniles and adults), and the von Bertalanffy model
was fitted: L
t
= 128[1 − exp{−0.003(t − 1.52)}], where L is the standard length (mm) and t is age in days. Age of C. warmingii ranged from 6 to 416 days, and growth before metamorphosis was linear (L
t
= 0.346t + 1.51), and the von Bertalanffy model was fitted to the postmetamorphosis stage: L
t
= 80.8 [1 − exp{−0.00769(t − 34.4)}]. Growth of these two lanternfishes was faster than that of other lanternfishes in previous studies but considerably
slower than that of Japanese sardine (Sardinops melanostictus) and anchovy (Engraulis japonicus) distributed in the Kuroshio–Oyashio Transition Zone. Temperature and prey availability are discussed in relation to this
difference in growth rate. 相似文献
7.
Filipendula ulmaria (L.) Maxim (meadowsweet) is a medicinal plant that is claimed to have several biological activities, including anti-tumor,
anti-carcinogenic, anti-oxidant, anti-coagulant, anti-ulcerogenic, anti-microbial, anti-arthritic, and immunomodulatory properties.
This report describes, for the first time, an efficient plant regeneration system for F. ulmaria via adventitious shoot development from leaf, petiole, and root explants cultured on Murashige and Skoog’s minimal organics
medium containing different concentrations of thidiazuron (TDZ), benzyladenine, and kinetin either alone or in combination
with different auxins. Relatively extensive/prolific shoot regeneration was observed in all three explant types with TDZ in
combination with indole-3-acetic acid (IAA). Gibberellic acid (GA3), TDZ, and IAA combinations were also tested. The best shoot proliferation was observed among root explants cultured on media
supplemented with 0.45 μM TDZ + 2.85 μM IAA + 1.44 μM GA3. Regenerated shoots were transferred to rooting media containing different concentrations of either IAA, indole-3-butyric
acid (IBA), naphthalene acetic acid, or 2,4-dichlorophenoxyacetic acid. Most shoots developed roots on medium with 2.46 μM
IBA. Rooted explants were transferred to vermiculite in Magenta containers for a 2-wk acclimatization period and then finally
to plastic pots containing potting soil. The plantlets in soil were kept in growth chambers for 2 wk before transferring to
greenhouse conditions. 相似文献
8.
L. Buendía-González J. Orozco-Villafuerte F. Cruz-Sosa V. M. Chávez-Ávila E. J. Vernon-Carter 《In vitro cellular & developmental biology. Plant》2007,43(3):260-266
Plantlet regeneration in Prosopis laevigata (Humb. & Bonpl. ex Willd.) Johnston (Fabaceae), a multipurpose tree, has been achieved from cotyledonary nodes excised from
in vitro grown seedlings. The explants were cultured on MS media containing different concentrations of N-6 benzyladenine (BA) and
2,4-dichlorophenoxyacetic acid (2,4-d) and a mixture of organic components. The highest number (3.37 + 0.51) of multiple shoots was observed in MS media containing
2,4-d (9.05 μM) + BA (6.62 μM). The regenerated shoots were then transferred onto half-strength MS medium containing a plant growth
regulator that was either: indole-3-butyric acid, 1-naphthaleneacetic, indole-3-acetic acid, or 2,4-d as well as phytagel or vermiculite for adventitious root initiation. Best rooting efficiency of 44.0% was obtained when NAA
(16.11 μM) and vermiculite were used. After rooting, the cloned plantlets were successfully hardened to ex vitro conditions. This work may help to reduce the devastation caused by the overexploitation of this species. 相似文献
9.
Ueda M Ohata K Konishi T Sutrisno A Okada H Nakazawa M Miyatake K 《Applied microbiology and biotechnology》2009,81(6):1077-1085
In this study, we cloned the gene encoding goose-type (G-type) lysozyme with chitinase (Ra-ChiC) activity from Ralstonia sp. A-471 genomic DNA library. This is the first report of another type of chitinase after the previously reported chitinases
ChiA (Ra-ChiA) and ChiB (Ra-ChiB) in the chitinase system of the moderately thermophilic bacterium, Ralstonia sp. A-471 and also the first such data in Ralstonia sp. G-type lysozyme gene. It consisted of 753 bp nucleotides, which encodes 251 amino acids including a putative signal peptide.
This ORF was modular enzyme composed of a signal sequence, chitin-binding domain, linker, and catalytic domain. The catalytic
domain of Ra-ChiC showed homologies to those of G-type lysozyme (glycoside hydrolases (GH) family 23, 16.8%) and lysozyme-like
enzyme from Clostridium beijerincki (76.1%). Ra-ChiC had activities against ethylene glycol chitin, carboxyl methyl chitin, and soluble chitin but not against
the cell wall of Micrococcus lysodeikticus. The enzyme produced α-anomer by hydrolyzing β-1,4-glycosidic linkage of the substrate, indicating that the enzyme catalyzes
the hydrolysis through an inverting mechanism. When N-acetylglucosamine hexasaccharide [(GlcNAc)6] was hydrolyzed by the enzyme, the second and third glycosidic linkage from the
non-reducing end were split producing (GlcNAc)2 + (GlcNAc)4 and (GlcNAc)3 + (GlcNAc)3 of almost the same concentration in
the early stage of the reaction. The G-type lysozyme hydrolyzed (GlcNAc)6 in an endo-splitting manner, which produced (GlcNAc)3 + (GlcNAc)3
predominating over that to (GlcNAc)2 + (GlcNAc)4. Thus, Ra-ChiC was found to be a novel enzyme in its structural and functional
properties.
The sequence data reported in the present paper have been submitted to the DDBJ, EMBL, and NCBI databases under the accession
number AB45458. 相似文献
10.
A Population Analysis of the Structure and Variability of NOR in Salmo Trutta by Ag, CMA3 and ISH 总被引:1,自引:0,他引:1
An analysis of the variation in the number and location of rDNA genes has been carried out in two populations of brown trout
(Salmo trutta) from Poland by using Ag and CMA3-staining, and rDNA in situ hybridisation. We observed an interindividual variation in arm number with NF = 100, 101, and 102. This variation was connected
with the size polymorphism of the short (NOR-bearing) arm of the chromosome pair 11. The population studied showed a multichromosomal
distribution of active NORs. Atypical Ag-NORs consisted of rDNA genes, as evidenced by rDNA-ISH. In addition to individuals
with standard NORs, specimens with extra NORs as well as others with only one active NOR and single interphase nucleolus were
observed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
11.
The chromosomes of 31 species of Passiflora, distributed throughout the subgenera Astrophea, Calopathanthus, Distephana, Dysosmia, Passiflora, Plectostemma and Tacsonia were analysed. Three different karyotypes were observed: 2n = 12, 24, 36; 2n = 18, 72 and 2n = 20. The karyotype of these
species was almost always constituted of metacentric and submetacentric chromosomes with variable karyotype symmetry. In the
group with x = 6, represented by the subgenus Plectostemma, six diploid species with 2n = 12, one tetraploid with 2n = 24 (P. suberosa) and an intraspecific polyploid with 2n = 12, 36 (P. misera) were analysed. P. pentagona (subgenus Astrophea) may also be included in this karyological group since it presents 2n = 24 and may be of polyploid origin, with x = 6. The
interphase nuclei in this group were areticulate, except those of P. morifolia and P. pentagona with semi-reticulate characteristics. Two small terminal heterochromatic blocks, positive for chromomycin A3, were identified in the largest chromosome pair of P. capsularis and P. rubra, species very closely related, while P. tricuspis displayed four chromosomes with proximal blocks. In the group with x = 9, represented mainly by subgenus Passiflora, 20 species with 2n = 18 and one with 2n = 72 were studied. They presented chromosomes larger than those species with x = 6
and interphase nuclei of semi-reticulate type, except for P. mixta with areticulate nuclei. Four terminal CMA+ blocks were observed in P. edulis, six blocks in P. caerulea and P. racemosa, while five blocks were observed in the single P. amethystina plant analysed. P. foetida (subgenus Dysosmia), the only species with 2n = 20, exhibited six chromosomes with CMA+ blocks and interphase nuclei of the areticulate type. The meiotic analysis of representatives of the three groups (P. foetida, P. suberosa, P. cincinnata and P. racemosa) always presented regular pairing and regular chromosome segregation, except in P. jilekii where a tetravalent was observed. The analysis of the chromosome variation within the genus and the family suggests that
the base number of Passiflora may be x1 = 6 or x1 = 12, whereas x2 = 9 is only an important secondary base number.
Received April 11, 2000 Accepted October 5, 2000 相似文献
12.
Lan Q Shen M Garcia-Rossi D Chanock S Zheng T Berndt SI Puri V Li G He X Welch R Zahm SH Zhang L Zhang Y Smith M Wang SS Chiu BC Linet M Hayes R Rothman N Yeager M 《Immunogenetics》2007,59(11):839-852
Selection and genetic drift can create genetic differences between populations. Cytokines and chemokines play an important
role in both hematopoietic development and the inflammatory response. We compared the genotype frequencies of 45 SNPs in 30
cytokine and chemokine genes in two healthy Chinese populations and one Caucasian population. Several SNPs in IL4 had substantial genetic differentiation between the Chinese and Caucasian populations (F
ST ~0.40), and displayed a strikingly different haplotype distribution. To further characterize common genetic variation in
worldwide populations at the IL4 locus, we genotyped 9 SNPs at the IL4 gene in the Human Diversity Panel’s (N = 1056) individuals from 52 world geographic regions. We observed low haplotype diversity, yet strikingly different haplotype
frequencies between non-African populations, which may indicate different selective pressures on the IL4 gene in different parts of the world. SNPs in CSF2, IL6, IL10, CTLA4, and CX3CR1 showed moderate genetic differentiation between the Chinese and Caucasian populations (0.15 < F
ST < 0.25). These results suggest that there is substantial genetic diversity in immune genes and exploration of SNP associations
with immune-related diseases that vary in incidence across these two populations may be warranted. 相似文献
13.
Simultaneous nutrients and carbon removal during pretreated swine slurry degradation in a tubular biofilm photobioreactor 总被引:1,自引:0,他引:1
Ignacio de Godos Cristina González Eloy Becares Pedro A. García-Encina Raúl Muñoz 《Applied microbiology and biotechnology》2009,82(1):187-194
The biodegradation potential of an innovative enclosed tubular biofilm photobioreactor inoculated with a Chlorella sorokiniana strain and an acclimated activated sludge consortium was evaluated under continuous illumination and increasing pretreated
(centrifuged) swine slurry loading rates. This photobioreactor configuration provided simultaneous and efficient carbon, nitrogen,
and phosphorous treatment in a single-stage process at sustained nitrogen and phosphorous removals efficiencies ranging from
94% to 100% and 70–90%, respectively. Maximum total organic carbon (TOC), NH4
+, and PO4
3− removal rates of 80 ± 5 g C mr
−3 day−1, 89 ± 5 g N mr
−3 day−1, and 13 ± 3 g P mr
−3 day−1, respectively, were recorded at the highest swine slurry loadings (TOC of 1,247 ± 62 mg L−1, N–NH4
+ of 656 ± 37 mg L−1, P–PO4
3+ of 117 ± 19 mg L−1, and 7 days of hydraulic retention time). The unusual substrates diffusional pathways established within the phototrophic
biofilm (photosynthetic O2 and TOC/NH4
+ diffusing from opposite sides of the biofilm) allowed both the occurrence of a simultaneous denitrification/nitrification
process at the highest swine slurry loading rate and the protection of microalgae from any potential inhibitory effect mediated
by the combination of high pH and high NH3 concentrations. In addition, this biofilm-based photobioreactor supported efficient biomass retention (>92% of the biomass
generated during the pretreated swine slurry biodegradation). 相似文献
14.
Ribitsch D Karl W Wehrschütz-Sigl E Tutz S Remler P Weber HJ Gruber K Stehr R Bessler C Hoven N Sauter K Maurer KH Schwab H 《Applied microbiology and biotechnology》2009,81(5):875-886
In the course of a microbial screening of soil samples for new oxidases, different enrichment strategies were carried out.
With choline as the only carbon source, a microorganism was isolated and identified as Arthrobacter nicotianae. From this strain, a gene coding for a choline oxidase was isolated from chromosomal DNA. This gene named codA was cloned in Escherichia coli BL21-Gold and the protein (An_CodA) heterologously overexpressed as a soluble intracellular protein of 59.1 kDa. Basic biochemical characterization of
purified protein revealed a pH optimum of 7.4 and activity over a broad temperature range (15–70 °C). Specific activities
were determined toward choline chloride (4.70 ± 0.12 U/mg) and the synthetic analogs bis(2-hydroxyethyl)-dimethylammonium
chloride (0.05 ± 0.45 × 10–2 U/mg) and tris-(2-hydroxyethyl)-methylammonium methylsulfate (0.01 ± 0.12 × 10–2 U/mg). With increasing number of oxidizable groups, a significant decrease in activity was noted. Determination of kinetic
parameters in atmorspheric oxygen resulted in K
M = 1.51 ± 0.09 mM and V
max = 42.73 ± 0.42 mU/min for choline chloride and K
M = 4.77 ± 0.76 mM and V
max = 48.40 ± 2.88 mU/min for the reaction intermediate betaine aldehyde respectively. Nuclear magnetic resonance spectroscopic
analysis of the products formed during the enzyme reaction with choline chloride showed that in vitro the intermediate betaine
aldehyde exists also free in solution. 相似文献
15.
The kinetics of NH4
+ and NO3
− uptake in young Douglas fir trees (Pseudotsuga menziesii [Mirb.] Franco) were studied in solutions, containing either one or both N species. Using solutions containing a single N
species, the Vmax of NH4
+ uptake was higher than that of NO3
− uptake. The Km of NH4
+ uptake and Km of NO3
− uptake differed not significantly. When both NH4
+ and NO3
− were present, the Vmax for NH4
+ uptake became slightly higher, and the Km for NH4
+ uptake remained in the same order. Under these conditions the NO3
− uptake was almost totally inhibited over the whole range of concentrations used (10–1000 μM total N). This inhibition by NH4
+ occurred during the first two hours after addition. ei]{gnA C}{fnBorstlap} 相似文献
16.
17.
Erika S. Zavaleta 《Plant Ecology》2006,184(1):53-63
Accelerating invasion of grasslands by woody species is a widespread global phenomenon. The native shrub Baccharis pilularis has recently increased in abundance in some California grasslands, with large local community and ecosystem effects. I investigated potential contributions of (1) future global climate and atmospheric changes and (2) variation in moisture and nutrient availability to increased Baccharis germination and early establishment rates. I examined responses of Baccharis seeds and seedlings to simulated warming (+ 1−2 °C) and elevated CO2 (+ 300 ppm) in a 2-year field experiment. Warming and CO2 treatments were applied at ambient and increased water and nitrogen levels chosen to simulate future increases in precipitation (+ 50%) and N deposition (+ 7 gN m−2 y−1). Elevated CO2 and water addition each increased or accelerated germination. Herbivory strongly reduced seedling populations during the winter wet season; drought further reduced seedling survival in the spring. Overall Baccharis survivorship was extremely low (<0.1%) across all treatments, complicating the interpretation of global change effects. 相似文献
18.
A. Carvalho H. Guedes-Pinto J. S. Heslop-Harrison J. Lima-Brito 《Plant Molecular Biology Reporter》2008,26(1):46-52
The DNA hypomethylation effect of 5-azacytine (5-AC; a cytosine analog) is widely known. This agent has been used for rRNA
gene expression studies of Triticeae amphiploids and hybrids regarding rye rRNA genes suppression caused by the wheat nucleolar dominance phenomenon. However,
this situation is reverted by 5-AC treatment which activates rye rRNA gene expression as it has been intensively observed
in triticale. For nucleolar dominance studies, we produced F1 multigeneric hybrids (AABBRHch; 2n = 6x = 42) from crosses between the triticale cultivar ‘Corgo’ (AABBRR; 2n = 6x = 42) and the tritordeum cultivars HT9 and HT31 (AABBHchHch; 2n = 6x = 42). The hybrid seeds were germinated in a low concentration of 5-AC (treatment) and in distilled water (nontreated control
plants). Silver nitrate staining performed in one 5-AC-treated F1 hybrid revealed a reduced number of interphase cells with
seven nucleoli, metaphases with eight Ag-NORs, and neocentromeres in the long arm of three wheat chromosomes. Nontreated hybrids
presented six Ag-NORs per mitotic metaphase cell and a maximum of six nucleoli per interphase because of the 1R Ag-NOR suppression.
No neocentromere was found in the control F1 hybrid plants. Both treated and nontreated seedlings were subsequently evaluated
by fluorescent in situ hybridization performed with genomic and repetitive DNA probes to identify Hch and rye genomes, to confirm Ag-NORs location, and to detect inactive rDNA loci. DAPI counterstaining was also helpful for
the detection of neocentromeres in the long arm of three wheat chromosomes. This study allowed us to suggest that 5-AC treatment
specifically induced wheat neocentromeres in the F1 multigeneric triticale × tritordeum hybrids. 相似文献
19.
Priya R Tadwal VS Roessle MW Gayen S Hunke C Peng WC Torres J Grüber G 《Journal of bioenergetics and biomembranes》2008,40(4):245-255
The first low resolution solution structure of the soluble domain of subunit b (b
22–156) of the Escherichia coli F1FO ATPsynthase was determined from small-angle X-ray scattering data. The dimeric protein has a boomerang-like shape with a
total length of 16.2 ± 0.3 nm. Fluorescence correlation spectroscopy (FCS) shows that the protein binds effectively to the
subunit δ, confirming their described neighborhood. Using the recombinant C-terminal domain (δ91–177) of subunit δ and the C-terminal peptides of subunit b, b
120–140 and b
140–156, FCS titration experiments were performed to assign the segments involved in δ–b assembly. These data identify the very C-terminal tail b
140–156 to interact with δ91–177. The novel 3D structure of this peptide has been determined by NMR spectroscopy. The molecule adopts a stable helix formation
in solution with a flexible tail between amino acid 140 to 145. 相似文献
20.
The aim of the present study was to evaluate whether aluminum exposure may cause alterations of cytochrome P
4503A4 by measuring the urinary excretion of 6β-hydroxycortisol as biomarker. There is a positive correlation between urinary
6β-hydroxycortisol and aluminum excretion (p < 0.05). The correlations between occupational duration, smoking habits, and age were also evaluated. The increased excretion
of the biomarker suggests that this element may induce formation of cytochrome P
450 in exposed individuals. 相似文献