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1.
Chen Dong Guolin Li Zhuoqi Li Honglin Zhu Mingquan Zhou Zhongli Hu 《Applied biochemistry and biotechnology》2009,158(3):605-614
A rapid amplification cDNA end (RACE) assay was established to achieve the complete sequence of mitochondrial manganese-superoxide
dismutase (Mn-SOD) cDNA in Nelumbo nucifera. The obtained full-length cDNA of Mn-SOD was 926 bp and contained a 699-bp open reading frame encoding an Mn-SOD precursor of 233 amino acids. The recombinant of
Mn-SOD expressed by PET-32a vector in Escherichia coli BL21 was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting assays. A 3D structural
model of the Mn-SOD was constructed by homology modeling. Real-time polymerase chain reaction analysis revealed that Mn-SOD mRNA was expressed in young leaves, blossom, stems, and terminal buds during reproductive stage but with the highest expression
in young leaves. This significant difference demonstrated the differential expression of Mn-SOD in various organs of N. nucifera. 相似文献
2.
D. A. Köse G. Gökçe S. Gökçe İ. Uzun 《Journal of Thermal Analysis and Calorimetry》2009,95(1):247-251
Three novel mixed ligand complexes of Ni(II), Zn(II) and Cd(II) with p-chlorobenzote and N,N-diethylnicotinamide were synthesised and characterized on the basis of elemental analysis, FTIR spectroscopic
analysis, solid state UV-Vis spectrometric and magnetic susceptibility data. The thermal behavior of the complexes was studied
by simultaneous TG-DTA methods in static air atmosphere and the mass spectra data were recorded.
According to microanalytical results, formulas of complexes are C34H40N4O8ClNi, C34H40N4O8ClZn and C34H44N4O10ClCd. The complexes contain two moles of coordination waters, two moles p-chlorobenzoate and two mole N,N-diethylnicotinamide (dena) ligands per formula unit. In these complexes, the p-chlorobenzoate and N,N-diethylnicotinamide behave as monodentate ligand through acidic oxygen and nitrogen of pyridine ring.
The decomposition pathways and the stability of the complexes are interpreted in the terms of the structural data. The final
decomposition products were found to be as metal oxides. 相似文献
3.
The 5-aminolevulinate (ALA) synthase gene (hemA) from Agrobacterium radiobacter zju-0121, which was cloned previously in our laboratory, contains several rare codons. To enhance the expression of this
gene, Escherichia coli Rosetta(DE3), which is a rare codon optimizer strain, was picked out as the host to construct an efficient recombinant strain.
Cell extracts of the recombinant E. coli were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under the appropriate conditions. The results
indicated that the activity of ALA synthase expressed in Rosetta(DE3)/pET-28a(+)-hemA was about 20% higher than that in E. coli BL21(DE3). Then the effects of precursors (glycine and succinate) and glucose, which is an inhibitor for ALA dehydratase
as well as the carbon sources for cell growth, on the production of 5-aminolevulinate were investigated. Based on an optimal
fed-batch culture system described in our previous work, up to 6.5 g/l (50 mM) ALA was produced in a 15-l fermenter. 相似文献
4.
A novel plasma membrane intrinsic, LcPIP1, was isolated from Leymus chinensis using RACE method. The LcPIP1 has 288 amino acids with an estimated molecular mass of 30.6 kDa. Semi RT-PCR analysis indicated that the expression level
of LcPIP1 was obviously higher in leaf than root. The LcPIP1 was also found to be induced by salt stress. In addition, transformed with the LcPIP1, Saccharomyces cerevisiae could increase tolerance to salt stress. These results indicate that the LcPIP1 gene seems to play a role in resistance against salt stress. 相似文献
5.
Analysis of cellulose biosynthesis using molecular approaches has been successful in identifying genes in many cellulose-producing
organisms, yet the mechanism of cellulose biosynthesis still remains to be understood. We are interested in developing the
moss Physcomitrella patens as a useful system for the study of cellulose biosynthesis. This moss affords a number of advantages including a haploid
dominated gametophyte and a very high efficiency of homologous recombination in its nuclear DNA for constructing gene knockouts.
In addition, P. patens has only a primary cell wall unlike Arabidopsis thaliana, which has both a primary and a secondary cell wall. We identified two full-length cellulose synthase (CesA) genes of P. patens, PpCesA6 and PpCesA7 from an EST database and have analyzed the genomic sequences. PpCesA6 and PpCesA7 show high similarity to each other, both at the cDNA and genomic DNA levels. Single and double knockouts of PpCesA6 and PpCesA7 were generated and screened for phenotypic changes. While the PpCesA6 and PpCesA7 single knockouts did not show any obvious phenotypic differences from the wild-type, the double knockout had significantly
reduced stem length. These results suggest that PpCesA6 and PpCesA7 probably have a very similar role in cellulose biosynthesis and their functions may be redundant. Additionally, their roles
may overlap with the other P. patens CesAs as observed for CesAs involved in primary cell wall biosynthesis in A. thaliana. 相似文献
6.
A. S. Soldatenko Yu. I. Bolgova O. M. Trofimova T. N. Aksamentova N. N. Chipanina M. G. Voronkov 《Russian Journal of General Chemistry》2010,80(10):1918-1922
The hitherto unknown complexes of 1-(N-heterylmethyl)silatranes HetCH2Si(OCH2CH2)3N (Het is imidazolyl, 3,5-dimethylpyrazolyl, 1,2,4-triazolyl, benzimidazolyl, 1,2,3-benzotriazolyl) with chlorides of divalent
metals MCl2 (M = Cu, Zn, Cd, Co, Pd) of 1:1 composition are synthesized. The ligands are coordinated to the metal ion by the pyridine
nitrogen atom of the azole heterocycle. 相似文献
7.
Yun Wang Jin-Zhu Song Qian Yang Zhi-Hua Liu Xiao-Mei Huang Yan Chen 《Applied biochemistry and biotechnology》2010,162(3):843-854
A gene encoding chitin deacetylase was cloned by polymerase chain reaction from Aspergillus nidulans. Sequencing result showed 40% homology to the corresponding gene from Colletotrichum lindemuthianum. The complete gene contains an open reading frame of 747 nucleotides encoding a sequence of 249 amino acid residues. The
chitin deacetylase gene was subcloned into a pET28a expression vector and expressed in Escherichia coli BL21 and then purified by metal affinity chromatography using a His-bind column. The purified chitin deacetylase demonstrated
an activity of 0.77 U ml−1 for the glycol chitin substrates, and its specific activity was 4.17 U mg−1 for it. The optimal temperature and pH of the purified enzyme were 50 °C and 8.0, respectively. When glycol chitin was used
as the substrate, K
m was 4.92 mg ml−1, and K
cat showed 6.25 s−1, thus the ratio of K
cat and K
m was 1.27 ml s−1 mg−1. The activity of chitin deacetylase was affected by a range of metal ions and ethylenediaminetetraacetic acid. 相似文献
8.
A number of (Z)-N,N-dialkyl- and (Z)-N-acyl-N-alkyl-O-methylnicotinamide oximes was synthesized. Their configuration was confirmed by the NOESY experiment. Evaluation of fungicidal
activity of compounds obtained was performed. 相似文献
9.
A. V. Lezov G. E. Polushina A. A. Lezov P. S. Vlasov N. S. Domnina 《Polymer Science Series A》2011,53(2):93-101
The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH
values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied.
For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the
chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes.
In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid
units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer
and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the
copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm.
The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to
steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of
the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along
the chain contour. 相似文献
10.
T. F. Ibragimov M. G. Levkovich V. A. Saprykina Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2010,46(5):767-770
N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The
point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated. 相似文献
11.
12.
A type III polyketide biosynthetic gene cluster has been discovered in the industrially important strain Streptomyces toxytricini NRRL 15443, including four genes stp450-1, stts, stp450-2, and stmo. The stts gene encodes a putative type III polyketide synthase that is homologous to RppA, a 1,3,6,8-tetrahydroxynaphthalene (THN)
synthase from Streptomyces griseus. The deduced protein product of stmo resembles the cupin-containing monooxygenase MomA from Streptomyces antibioticus that oxidizes THN into flaviolin. Two cytochrome P450s (CYPs), StP450-1 and StP450-2, are present in the gene cluster. StTS
was overexpressed in Escherichia coli BL21(DE3) and identified as a THN synthase. The synthesized THN can be easily oxidized into flaviolin by air. Both CYPs were
reconstituted in E. coli BL21(DE3) and can oxidize flaviolin to form oligomers. The k
cat/K
m values for StP450-1 and StP450-2 were 0.28 and 0.71 min−1 mM−1, respectively. UV irradiation test showed that expression of StTS in E. coli BL21(DE3) significantly protects the cells from UV radiation, and coexpression of StTS and StP450-1 provides even stronger
protection. 相似文献
13.
Background
Adenylation of nicotinate mononucleotide to nicotinate adenine dinucleotide is the penultimate step in NAD+ synthesis. In Escherichia coli, the enzyme nicotinate mononucleotide adenylyltransferase is encoded by the nadD gene. We have earlier made an initial characterization in vivo of two mutant enzymes, NadD72 and NadD74. Strains with either mutation have decreased intracellular levels of NAD+, especially for one of the alleles, nadD72. 相似文献14.
Bhavana V. Mohite Sunil H. Koli Satish V. Patil 《Applied biochemistry and biotechnology》2018,186(1):199-216
Currently, the heavy metal pollution is of grave concern, and the part of microorganism for metal bioremediation should take into account as an efficient and economic strategy. On this framework, the heavy metal stress consequences on exopolysaccharide (EPS)-producing agricultural isolate, Pantoea agglomerans, were studied. The EPS production is a protective response to stress to survive and grow in the metal-contaminated environment. P. agglomerans show tolerance and mucoid growth in the presence of heavy metals, i.e., mercury, copper, silver, arsenic, lead, chromium, and cadmium. EDX first confirmed the metal accumulation and further, FTIR determined the functional groups involved in metal binding. The ICP-AES identified the location of cell-bound and intracellular metal accumulation. Metal deposition on cell surface has released more Ca2+. The effect on bacterial morphology investigated with SEM and TEM revealed the sites of metal accumulation, as well as possible structural changes. Each heavy metal caused distinct change and accumulated on cell-bound EPS with some intracellular deposits. The metal stress caused a decrease in total protein content and increased in total carbohydrate with a boost in EPS. Thus, the performance of P. agglomerans under metal stress indicated a potential candidate for metal bioremediation. 相似文献
15.
The development of the organisms extracellular and intracellular mechanisms for the uptake of heavy metals were conducted
by using the natural detoxification strategies of the organism to toxicity. Aspergillus foetidus was used as a test case organism to examine these processes. Aspergillus foetidus was adapted to multi-metals (Al, Co, Cr, Cu, Fe, Mg, Mn, Ni and Zn) by a sequential method for tolerance development. The
detoxification strategies of A. foetidus occurred by two mechanisms. The first mechanism is the production of extracellular metabolites that is capable of adsorbing
and precipitating the metal ions on the cell surface. The second mechanism for the detoxification of metals is the intracellular
binding of heavy metals to thiol containing compounds such as GSH and sequestering these metal–thiol complexes into sub-cellular
compartments or vacuoles. These detoxification strategies resulted in adapted organisms with tolerance to multi-heavy metals
concentrations and significantly higher metal uptake with adaptation. 相似文献
16.
Meijuan Xu Zhiming Rao Hong Xu Chunyan Lan Wenfang Dou Xiaomei Zhang Hongyu Xu Jian Jin Zhenghong Xu 《Applied biochemistry and biotechnology》2011,163(6):707-719
Corynebacterium crenatum SYPA 5-5 is an aerobic and industrial l-arginine producer. It was proved that the Corynebacterium glutamicum/Escherichia coli shuttle vector pJC1 could be extended in C. crenatum efficiently when using the chloramphenicol acetyltransferase gene (cat) as a reporter under the control of promoter tac. The expression system was applied to over-express the gene vgb coding Vitreoscilla hemoglobin (VHb) to further increase the dissolved oxygen in C. crenatum. As a result, the recombinant C. crenatum containing the pJC-tac-vgb plasmid expressed VHb at a level of 3.4 nmol g−1, and the oxygen uptake rates reached 0.25 mg A562−1 h−1 which enhanced 38.8% compared to the wild-type strain. Thus, the final l-arginine concentration of the batch fermentation reached a high level of 35.9 g L−1, and the biomass was largely increased to 6.45 g L−1, which were 17.3% and 10.5% higher than those obtained by the wild-type strain, respectively. To our knowledge, this is the
first report that the efficient expression system was constructed to introduce vgb gene increasing the oxygen and energy supply for l-arginine production in C. crenatum, which supplies a good strategy for the improvement of amino acid products. 相似文献
17.
A. V. Piskunov I. N. Meshcheryakova E. V. Baranov G. K. Fukin V. K. Cherkasov G. A. Abakumov 《Russian Chemical Bulletin》2010,59(2):361-370
New tin(iv) mono- and bis-o-iminosemiquinone complexes were obtained by the exchange reaction of radical anion lithium salt of 4,6-di-tert-butyl-N-(2,6-diisopropylphenyl)-o-imino-benzoquinone with tin(iv) organochlorides. The compounds synthesized were characterized by EPR spectroscopy and X-ray diffraction analysis. Substituents
on the tin atom were found to affect stability of paramagnetic metal derivatives formed. 相似文献
18.
N. P. Abdullaev U. S. Makhmudov B. Tashkhodzhaev G. Genzhemuratova M. G. Levkovich Kh. M. Shakhidoyatov 《Chemistry of Natural Compounds》2009,45(6):837-843
N-Acyl cytisine derivatives were synthesized by acylation with acetic anhydride; benzoyl and o-bromo- and p-nitrobenzoyl chlorides; and crotonyl and cinnamoyl chlorides. The structures of the synthesized compounds were studied using
IR, PMR, and x-ray structure analysis (XSA). PMR spectra of the N-acylcytisines in solution typically had two rotational isomers around the N12–CO bond. Conformational analysis was performed
using XSA for the position of the acyl group relative to the cytisine core. Bond lengths and angles of the acyl groups involved
in the conjugation were analyzed. 相似文献
19.
D. T. Asilbekova F. M. Tursunkhodzhaeva A. M. Nigmatullaev 《Chemistry of Natural Compounds》2009,45(3):322-324
The composition of lipids from the aerial parts of two species of halophytes from the family Chenopodiaceae, Halostachys caspica C. A. Mey. and Halocharis hispida Bge. was determined. Neutral lipids (NL, 62.1 and 54.2%, respectively) dominated the total lipids (TL) of these plants. More
than a third of the NL were esters of aliphatic alcohols and phytosterols (FAE). Fatty acids 16:0, 18:1, and 18:2 dominated
the acids of FAE; 16:0, 18:1, and 18:3, the phospholipids. The principal fatty acids of glycolipids were unsaturated acids
(68.3 and 75.1%) with linolenic acid dominating (44.9 and 43.5%).
Presented at the 7th International Symposium on the Chemistry of Natural Compounds, Tashkent, October 16–18, 2007.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 276–278, May–June, 2009. 相似文献
20.
P. A. Storozhenko Z. V. Belyakova O. A. Starikova V. M. Nosova T. I. Shulyat’eva A. S. Frenkel’ M. V. Pecherskii 《Russian Journal of General Chemistry》2008,78(5):892-897
N-Metallation of bromoanilines with ethylmagnesium bromide followed by a reaction with trimethylchlorosilane provided N-mono and N-bis(trimethylsilyl)bromoanilines depending on the structure of substrate. The metallation of bissilylated bromoanilines with butyllithium permitted the introduction of a trimethylsilyl substituent in the aromatic ring. Previously unknown 2-bromo-N,N-bis(trimethylsilyl)aniline, 2,6-dibromo-N-trimethylsilylaniline, 2,6-dibromo-N,N-bis(trimethylsilyl)aniline, 2-bromo-6-trimethylsilylaniline, 2-bromo-6-trimethylsilyl-N,N-bis(trimethylsilyl)aniline, 2-bromo-6-trimethylsilyl-N-trimethylsilylaniline, 2,4,6-tribromo-N-trimethylsilylaniline, and 2,4,6-tribromo-N,N-bis(trimethylsilyl)aniline were prepared. The structures of the compounds obtained were established by the chromato-mass spectrometry and 1H, 13C, and 29Si NMR spectroscopy. 相似文献