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1.
Nutritional Composition and Assessment of Gracilaria lemaneiformis Bory   总被引:1,自引:0,他引:1  
The chemical composition, mineral elements, vitamins, free fatty acids and amino acid content of the edible red alga Gracilaria lemaneiformis Bory, grown in the sea near Nan'ao island, Guangdong Province, were analyzed in the present study. Gracilaria lemaneiformis Bory showed a total sugar content of 14.65%. The protein content was 21%, of which approximately 41% was determined to be essential amino acids (EAA). The major amino acid components were glutamic acid, leucine, arginine, and alanine. Of the EAA assayed, methionine and cysteine appeared to be the most limiting amino acids compared with the EAA pattern provided by Food and Agricultural Organization of the United Nations. The total lipids content was 0.87% and comprised a high composition of unsaturated fatty acids (61%), mainly as linoleic acid and oleic acid, and a little amount of polyunsaturated fatty acid; palmitic acid was the main component (39%) of saturated acids. Relatively high levels of vitamin C, iodine, phosphorus, and zinc were also present in G. lemaneiformis. The nutritional composition between G. lemaneiformis and Nostoc flagelliforme, a rare alga that is widely eaten in Chinese society, was compared. The results suggest that N. flagelliforme can be substituted for by G. lemaneiformis, not only because of their similar shape, but also because of their approximate nutritional composition. Gracilaria lemaneiformis may possibly serve as a potential healthy food in human diets in the future.  相似文献   

2.
The biological functions of a protein are closely related to its attributes in a cell. With the rapid accumulation of newly found protein sequence data in databanks, it is highly desirable to develop an automated method for predicting the subcellular location of proteins. The establishment of such a predictor will expedite the functional determination of newly found proteins and the process of prioritizing genes and proteins identified by genomic efforts as potential molecular targets for drug design. The traditional algorithms for predicting these attributes were based solely on amino acid composition in which no sequence order effect was taken into account. To improve the prediction quality, it is necessary to incorporate such an effect. However, the number of possible patterns in protein sequences is extremely large, posing a formidable difficulty for realizing this goal. To deal with such difficulty, a well-developed tool in digital signal processing named digital Fourier transform (DFT) [1] was introduced. After being translated to a digital signal according to the hydrophobicity of each amino acid, a protein was analyzed by DFT within the frequency domain. A set of frequency spectrum parameters, thus obtained, were regarded as the factors to represent the sequence order effect. A significant improvement in prediction quality was observed by incorporating the frequency spectrum parameters with the conventional amino acid composition. One of the crucial merits of this approach is that many existing tools in mathematics and engineering can be easily applied in the predicting process. It is anticipated that digital signal processing may serve as a useful vehicle for many other protein science areas.  相似文献   

3.
The comprehensive knowledge that the delayed systemic and reproduction side effects can be even more deleterious than acute toxicity, has caused a shift in focus toward sublethal effects assessment on physiology and behavior of beneficial insects. In this study, we assessed the risks posed by some insecticides with different mode of action through lethal and delayed systemic sublethal effects on the pupation, adult emergence, and repro- duction of the chrysopid Chrysoperla externa (Hagen, 1861; Neuroptera: Chrysopidae), an important predator in pest biological control. The maximum field recommended dose (MFRD) and twice (2xMFRD) for chlorantraniliprole, tebufenozide, and pyriproxyfen were harmless to C. externa. In contrast, all the tested chitin synthesis inhibitors (CSIs) were highly detrimental to the predator, despite of their lack of acute lethal toxicity. There- fore, the safety assumed by using IGRs toward beneficial insects is not valid for chrysopids. Dose-response data showed that although all CSIs have a similar mechanism of action, the relative extent of toxicity may differ (novaluron 〉 lufenuron 〉 teflubenzuron). For CSIs, the delayed systemic effects became obvious at adult emergence, where the predicted no observable effect dose (NOED) was 1/2 048 of the MFRD for novaluron (0.085 ng/insect), and 1/256 of the MFRD for both lufenuron (0.25 ng/insect) and teflubenzuron (0.6 ng/insect). Finally, this work emphasized the significance of performing toxicity risk assessments with an adequate posttreatment period to avoid underestimating the toxicities of insecticides, as the acute lethal toxicity assays may not provide accurate information regarding the long-range effects of hazardous compounds.  相似文献   

4.
A sensitive and rapid single step real time (rt) RT-PCR was standardized using one-step Brilliant SYBR Green kit for detection and semi-quantitation of peste des petitis ruminants virus (PPRV) using the virus RNA and matrix (M) protein gene-specific primers and compared with established conventional RT-PCR and Taq Man RT-PCR. The assay amplifies a 124 bp fragment of the PPRV M gene with Tm of 78.28 to 78.50. The assay was linear within a range of 50 ng to 0.5 fg total virus RNA with a detection limit (sensitivity) of 0.5 fg. Based on the serial dilution of the live-attenuated PPR vaccine virus, the detection limit was ~0.0001 cell culture infectious dose 50% units (TCID50). Additionally, swab materials spiked with known titre of vaccine virus were equally well detected in the assay. The standardized rt RT-PCR was easily employed for the detection of PPRV nucleic acid directly in the field and experimental clinical samples. The assay detected the PPRV nucleic acid as early as 3 day post infection (dpi) and up to 20 dpi in swab materials from the experimental samples. The assay was rapid and more sensitive than TaqMan and conventional RT-PCR in the detection of PPRV nucleic acid from the PPR suspected clinical samples of sheep and goats. Therefore, the established, simplified SYBR green rt RT-PCR is an alternative test to the already existing various diagnostic assays and could be useful for rapid clinical diagnosis with advantage in reducing risk of contamination.  相似文献   

5.
The α_ 2u-globulin,a soluble protein identified in the urine and preputial gland of adult male rat is reported to be pheromone carrier.The pup preputial gland plays a significant role in chemical communication for mother-young interaction;however,the presence of a pheromone-carrying protein in the pup preputial gland has not been confirmed.Therefore,the present study was carried out to identify the α_ 2u-globulin in the pup preputial gland by Matrix Assisted Laser Desorption Ionization Time of Flight mass s...  相似文献   

6.
The wheat midge, Sitodiplosis mosellana, is a serious pest of wheat worldwide. In North America, management of S. mosellana in spring wheat relies on the timely application of pesticides, based on midge adults levels caught in pheromone traps or seen via field scouting during wheat heading. In this context, biopesticides can be an effective alternative to pesticides for controlling S. mosellana within an Integrated Pest Management program. A field study using insect pathogenic fungus Beauveria bassiana GHA, nematode Steinernema Jeltiae with Barricade polymer gel 1%, pyrethrin, combined formulations of B. bassiana GHA and pyrethrin, Jasmonic acid (JA) and chlorpyrifos (chemical check) was performed to determine to which extent they affect midge larval populations, kernel damage levels, grain yield, and quality, and the impacts on adult parasitoid Macroglenes penetrans populations. The results indicated that biopesticides JA and S. Jeltiae were the most effective in reducing larval populations and kernel damage levels, and produced a higher spring wheat yield when compared to the water control at both study locations (East Valier and North Valier, Montana, USA). Increased test weight in wheat had been recorded with two previous biopesticides at East Valier but not for North Valier, when compared over water control. These results were comparable in efficacy to the chlorpyrifos. This study also suggested that B. bassiana and pyrethrin may work synergistically, as exemplified by lower total larval populations and kernel damage levels when applied together. This study did not demonstrate the effect of any treatments on M. penetrans populations.  相似文献   

7.
In this study, an attempt has been made to predict the major functions of gramnegative bacterial proteins from their amino acid sequences. The dataset used for training and testing consists of 670 non-redundant gram-negative bacterial proteins (255 of cellular process, 60 of information molecules, 285 of metabolism, and 70 of virulence factors). First we developed an SVM-based method using amino acid and dipeptide composition and achieved the overall accuracy of 52.39% and 47.01%, respectively. We introduced a new concept for the classification of proteins based on tetrapeptides, in which we identified the unique tetrapeptides significantly found in a class of proteins. These tetrapeptides were used as the input feature for predicting the function of a protein and achieved the overall accuracy of 68.66%. We also developed a hybrid method in which the tetrapeptide information was used with amino acid composition and achieved the overall accuracy of 70.75%. A five-fold cross validation was used to evaluate the performance of these methods. The web server VICMpred has been developed for predicting the function of gram-negative bacterial proteins (http://www.imtech.res.in/raghava/vicmpred/).  相似文献   

8.
9.
Rapid Identification of Rice Samples Using an Electronic Nose   总被引:2,自引:0,他引:2  
Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety ofrice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors.TheCyranose-320 was able to differentiate between varieties of rice.The chemical composition of the rice odors for differentiatingrice samples needs to be investigated.The optimum parameter settings should be considered during the Cyranose-320 trainingprocess especially for multiple samples,which are helpful for obtaining an accurate training model to improve identificationcapability.Further,it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy.A re-duced number of sensors could potentially shorten the data processing time,and could be used to establish an application pro-cedure and reduce the cost for a specific electronic nose.Further research is needed for developing analytical procedures thatadapt the Cyranose-320 as a tool for testing rice quality.  相似文献   

10.
Omega-3(ω-3) fatty acid desaturase transgenic pigs may improve carcass fatty acid composition. The use of transgenic pigs is also an excellent large animal model for studying the role of ω-3 fatty acids in the prevention and treatment of coronary heart disease and cancer. Transgenic pigs carrying synthesized fatty acid desaturase-1 gene (sFat-1) from Caenorhabditis briggsae by somatic cell nuclear transfer (SCNT) were produced for the first time in China. Porcine fetal fibroblast cells were transfected with a sFat-1 expression cassette by the liposome-mediated method. Transgenic embryos were reconstructed by nuclear transfer of positive cells into enucleated in vitro matured oocytes. A total of 1889 reconstructed embryos were transferred into 10 naturally cycling gilts. Nine early pregnancies were established, 7 of which went to term. Twenty-one piglets were born. The cloning efficiency was 1.1% (born piglets/transferred embryos). The integration of the sFat-1 gene was confirmed in 15 live cloned piglets by PCR and Southern blot except for 2 piglets. Expression of the sFat-1 gene in 12 of 13 piglets was detected with RT-PCR. The data demonstrates that an efficient system for sFat-1 transgenic cloned pigs was developed, which led to the successful production of piglets expressing the sFat-1 gene.  相似文献   

11.
A new lectin, named UPL1, was purified from a green alga Ulvapertusa by an affinitychromatography on the bovine-thyroglobulin-Sepharose 4B column. The molecular mass of the algal lectinwas about 23 kD by SDS-PAGE, and it specifically agglutinated rabbit erythrocytes. The hemagglutinatingactivity for rabbit erythrocytes could be inhibited by bovine thyroglobulin and N-acetyl-D-glucosamine. Thelectin UPL1 required divalent cations for maintenance of its biological activity, and was heat-stable, and hadhigher activity within pH 6-8. The N-terminal amino acid sequence of the purified lectin was determined(P83209) and a set of degenerate primers were designed. The full-length cDNA of the lectin was cloned byrapid amplification ofcDNA ends (RACE) method (AY433960). Sequence analysis of upll indicated it was! 084 bp long, and encoded a premature protein of 203 amino acids. The N-terminal sequence of the matureUPL1 polypeptide started at amino acid 54 of the deduced sequence from the cDNA, indicating 53 aminoacids lost due to posttranslational modification. The primary structure of the Ulva pertusa lectin did not showamino acid sequence similarity with known plant and animal lectins. Hence, this protein may be the paradigmof a novel lectin family.  相似文献   

12.
Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion (UGS) of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry (GC-MS), we analyzed the UGS volatiles of domesticated Bengalese finches ( Lonchura striata, Estrildiea) which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages (relative abundances) . Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than in females and the latter richer in females than in males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that these compounds might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species, i. e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13 - C18 alkanols in the UGS might code for information about species. Our study also showed that quantitative differences (degree) of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [ Current Zoology 55 (5): 357-365, 2009].  相似文献   

13.
In the baculovirus shuttle vector(bacmid) system, a helper plasmid and a donor plasmid are employed to insert heterologous genes into a cloned baculovirus genome via Tn7 transposition in Escherichia coli. The helper and donor plasmids are usually cotransfected with constructed bacmids into insect cells, which will lead to integration of these plasmids into the viral genome,and hence to the production of defective virions. In this study, to facilitate the preparation of plasmid-free recombinant bacmids, we modified a set of helper and donor plasmids by replacing their replication origins with that of a temperature-sensitive(ts) plasmid, p SIM6. Using the resulting ts helper plasmid p MON7124 ts and the ts donor plasmid p FB1ts-PH-GFP, a recombinant bacmid,b Ac WT-PG(-), was constructed, and the transposition efficiency was found to be 33.1%. The plasmids were then removed by culturing at 37 °C. For b Ac WT-PG(-), the infectious progeny virus titer and the protein expression level under the control of the polyhedrin promoter were similar to those of a bacmid constructed with unmodified helper and donor plasmids. These ts plasmids will be useful for obtaining plasmid-free bacmids for both heterologous protein production and fundamental studies of baculovirus biology.  相似文献   

14.
Summary The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (160 nM) and the secondary bile acid, deoxycholic acid (50 μM) stimulated DNA synthesis in quiescent primary epithelial cells from the normal mouse colon as measured by autoradiographic analysis of [3H]thymidine incorporation. The purpose of the present study was to investigate the involvement of protein kinase C in the proliferative response of the normal colonic cells. The protein kinase C inhibitor, bisindolylmaleimide GF 109203X, efficiently blocked the proliferative response of the cells to the phorbol ester and caused a dose-dependent decrease in the response to deoxycholic acid. While the phorbol ester-induced proliferation was unaffected by another inhibitor, H-7, the response of the cells to deoxycholic acid was blocked. Pretreatment of the cells with the phorbol ester (160 nM) for 24 h blocked the proliferative response to deoxycholic acid. Measurement of the intracellular distribution of protein kinase C activity showed a time-dependent and significant translocation of the enzyme activity from the soluble to the particulate cell fractions after exposure to 12-O-tetradecanoylphorbol-13-acetate. While exposure to the bile acid indicated a similar time-dependent translocation of the enzyme activity, the effect was not significant. The phorbol ester induced a time-dependent accumulation of c-fos mRNA and protein as measured by solution hybridization and immunocytochemistry, respectively. No effect of deoxycholic acid on c-fos expression could be observed in the present study. The data support a role for protein kinase C in the growth stimulating effect of physiological concentrations of deoxycholic acid on normal colonic epithelial cells. However, differences in the mechanisms underlying phorbol ester- and bile acid-induced proliferation are indicated.  相似文献   

15.
The aim of the present work was to investigate the effects of osmoconditioning on chilling injury in chilling-sensitive soybean (Glycine max (L.) Merr. Zhonghuang No. 22) seeds during imbibition. Low temperatures reduced the germination rate and no seed germinated at 1 ℃. Osmoconditioning of seeds at 20℃ with a polyethylene glycol-8000 (PEG8000) solution at 1.5 MPa for 72 h followed by drying back to their initial moisture content (MC) reduced their chilling sensitivity. The phenylarsine oxide (PAO), an inhibitor of protein tyrosinephosphatases, was used to investigate the possible involvement of phosphorylation-dephosphorylation of Tyr residues in the plasma membrane composition and function when seeds were osmoconditioned. The results showed the germination of osmoconditioned seeds decreased significantly when PAO was added in PEG solution after chilling treatment. PAO inhibited changes in composition of plasma membrane phospholipids and fatty acid induced by osmocondition, indicated that tyrosine protein phosphorylation is involved in the regulatory mechanisms of osmocondition-responsive chilling in soybean seeds. Western blot result further indicated that osmocondition treatment improved the activity of plasma membrane H^+-ATPase after chilling treatment, but this effect was abolished by PAO. The possible regulation mechanism by Tyr protein phosphorylation is discussed.  相似文献   

16.
17.
Electrically induced protoplast fusion was used to produce somatic hybrids between Brassica napus L. and Sinapis alba L. Seven hybrids were obtained and verified by the simple sequence repeat and cleaved amplified polymorphic sequence analysis of the genefael, indicating that the characteristic bands from S. alba were present in the hybrids. The hybridity was also confirmed by chromosome number counting because the hybrids possessed 62 chromosomes, corresponding to the sum of fusion-parent chromosomes. Chromosome pairing at meiosis was predominantly normal, which led to high pollen fertility,ranging from 66% to 77%. All hybrids were grown to full maturity and could be fertilized and set seed after self-pollination or back-crosses with B. napus. The morphology of the hybrids resembled characteristics from both parental species. An analysis of the fatty acid composition in the seeds of F1 plants was conducted and the seeds were found to contain different amounts of erucic acid, ranging from 11.0% to 52.1%.  相似文献   

18.
Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6-7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fib-rillarin are two major protein components of nucleolar skeleton of HeLa cells.  相似文献   

19.
Qi H  Pei D 《Cell research》2007,17(7):578-580
The developmental process from a fertilized egg to agrown adult is programmed with remarkable accuracy.While the genetic information of the fertilized egg and itsdescendent somatic cells are the same, it is the selectiveexpressions of the same genome that give rise to the 200or so different cell types in an adult. The differentiatedstates of these adult cells are maintained epigenetically,presumably through the modification of chromatins and theassociated histones. In higher mammals, it was thought thatthe differentiation process is irreversible until the successfulcloning of Dolly [1]. By transferring a nucleus from a fullydifferentiated cell in the mammary gland, Wilmut and col-leagues were able to generate an exact replica of a highermammal, the Doily [1]. This work not only demonstratedthat the genome of differentiated cells can be reprogrammedinto an embryonic state and then to resume a full-fledgeddevelopmental process to generate a normal adult, but alsorejuvenated the field of animal cloning. The prospect thata somatic cell from a patient may be reprogrammed to the  相似文献   

20.
Isolation of a cDNA encoding a protease from Perinereis aibuhitensis Grube   总被引:2,自引:0,他引:2  
The cDNA encoding a protease of Perinereis aibuhitensis Grube (PPA) was cloned. The deduced amino acid sequence analysis showed that the protein had 49% identity to the C-terminal amino acid 169-246 of serine protease of Heterodera glycines. Northern blotting analysis indicated that the cDNA could hybridize with mRNA of approximately 260 bases isolated from the marine earthworm. The cDNA was amplified by polymerase chain reaction and cloned into pMAL-p2 to construct expression vector pMAL-PPA. pMAL-PPA was introduced into Escherichia coli BL21(DE3) and overexpression of PPA fused with maltose binding protein was achieved by isopropyl-β-D-thiogalactopyranoside induction. The fusion protein was purified by affinity chromatography on an amylose resin column and ion-exchange chromatography on a diethylaminoethyl-Sepharose 4B column. Rabbits were immunized with the purified protein and antiserum was prepared. The antibody could react with a protein of approximately 9 kDa extracted from the marine earthworm as shown by Western blotting analysis. The activity analysis of the recombinant PPA suggested that it was probably a plasminogen activator.  相似文献   

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