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1.
Five SDS-proteins, ranging in molecular weight from 14 to 66 kDa, were detected without covalent fluorescent labeling by the automated gel electrophoresis apparatus with intermittent fluorescence scanning (HPGE apparatus, LabIntelligence) during electrophoresis in barbiturate buffer in the presence of Cascade Blue. The SDS-proteins were electroeluted from the gel into 220 microl of buffer by a modification of the procedure of Gombocz and Cortez. The electroeluate was freed of SDS, ultrafiltered and subjected to MALDI-TOF mass spectrometry. The masses of the five native proteins were found to be maintained after electrophoresis and electroelution in the presence of the potential contaminants SDS, barbituric acid and Cascade Blue. The procedure of protein transfer from SDS-PAGE into mass spectrometry, without excision of bands, gel maceration and protein recovery by diffusion, therefore is shown to be suitable for the identification by mass of intact proteins derived from gel electrophoretic bands.  相似文献   

2.
Mass spectrometric analysis of proteins derived from bands in gel electrophoresis is incompatible with the covalent fluorescent labeling of the protein. Thus, if one wishes to take advantage of the capacity for computer-directed electroelution of electrophoresis apparatus with intermittent fluorescent scanning of the migration path, the protein must be labeled fluorescently in a noncovalent, reversible fashion. This was recently achieved by staining of SDS-proteins with Cascade blue and electrophoresis in barbital buffer. However, the method was not a practical one for the purpose of isolating proteins from gel electrophoretic bands and their transfer into the mass spectrometer for three reasons: (i) Ten consecutive electroelution steps were required to obviate pH changes in the electroelution chamber; (ii) electroeluates from six gel electrophoretic lanes needed to be pooled; (iii) excessive protein loads ranging from 7 to 33 microg/pool were required. The present study reports the solution to those three problems. Mass spectrometric (MALDI-TOF) characterization of five proteins was demonstrated (i) after a single electroelution step; (ii) using electroelution from a single gel of 0.3-cm(2) cross-sectional area; and (iii) using a protein load of 2 (in one case 4) microg. However, the migration rates of the Cascade blue-SDS-protein-barbital complexes derived from proteins with widely varying molecular weights proved to be the same. Thus, despite the three advances made, the method to date remains restricted to samples of single proteins.  相似文献   

3.
The zone dispersions of the reduced subunit of β-lactoglobulin B and its derivative with sodium dodecyl sulfate (SDS) were measured during polyacrylamide gel electrophoresis (PAGE) using the apparatus for continuous optical scanning at 280 nm. The ratio of apparent diffusion coefficients (D′) of the reduced subunit of β-lactoglobulin B (1.71 × 10?6 cm2/s) and of its SDS-derivative (7.1 × 10?7 cm2/s) was found to be 2.4 under the conditions of PAGE (pH 10.4, 0.015 ionic strength, 1°C, 4 mA/cm2 current density, 50 μg protein load, 10% T gel) used. This is nearly twice the value of 1.3 predicted, under the assumption of sphericity for these protein molecules, on the basis of the binding of 1.4 g of SDS per gram of protein. It is postulated that the increment in zone sharpness (decrease in apparent diffusion coefficient) over that predicted by SDS binding alone is a general property of SDS-proteins providing gel electrophoresis in SDS-containing buffers with a resolving power larger than that obtained in the absence of the detergent.  相似文献   

4.
Electrophoresis for SDS-proteins and isoenzymes was applied to investigate the genetic variability within the tropical grasshopper Poecilocerus bufonius, which inhabits Saudi Arabia. Samples were selected from different localities that are encompassing the Sarawat Mountains in the west and An-Nafud desert in the north and middle. A range of 2 to 14 protein bands were recorded in the studied samples as measured by SDS-polyacrylamide gel electrophoresis, from which only two were common. The maximum number of protein bands has been recorded in the samples from the west and the minimum number has been recorded in the samples from the north and middle. Six arbitrary chosen enzymes were examined by native-polyacrylamide gel electrophoresis. They were peroxidase (Px), aldehyde oxidase (Ao), acid phosphatase (Acph), alcohol dehydrogenase (Adh), á and â ePsterase (Est). Fourteen presumptive gene loci and 26 polymorphic alleles have been recorded with the highest number of alleles in Taif and minimum number of alleles in Qassim. Adh, Px and Acph have not been recorded in samples from the localities of An-Nafud desert. The samples from Taif (Sarawat Mountains) were more genetically variable than the samples from other localities. Most of alleles were monomeric but only the Px-1 showed trimeric alleles in samples from Taif.  相似文献   

5.
Aerobiological monitoring enables the definition of seasonal fungal spore concentrations and also intradiurnal time when the highest concentrations of spores could cause or increase allergy symptoms. These data are useful to estimate symptoms of disease, duration of infection and how advanced the illness is in people suffering from fungal allergens. The aim of the study was to compare the concentrations of fungal spores (Alternaria, Botrytis, Cladosporium, Didymella, Ganoderma) during dry and rainy periods and to analyse their intradiurnal changes. Average daily spore concentrations in dry and rainy periods were compared, using z test, separately for each taxon, season and for a combined 3-year period. Intradiurnal periodicity of fungal spore concentrations was analysed on the basis of three complementary diagrams. These spore concentrations were presented using three curves for all, dry and rainy days in 1997–1999 (April–November). The spore percentage in particular hours was normalized in relation to the daily spore sum accepted as 100%. Two further diagrams enabled the more precise analysis of the highest concentrations in dry days. Daily Botrytis and Cladosporium spore concentrations did not show significant differences between dry and rainy periods. In the case of Didymella and Ganoderma spore concentrations, there were no significant differences between both weather types in the single years, although there was a significant difference when a 3-year period was considered. The differences between daily concentrations of Alternaria spores in dry and rainy periods occurred in 1997 and in a 3-year period. Intradiurnal periodicity of spore concentrations was different for ‘dry’ and ‘wet’ fungal spores. Dry spores are released from the spore-producing parts of the fungus under conditions of decreasing humidity and increasing airflow. Examples of dry spores are those from Alternaria, Cladosporium and Botrytis. Wet spores, such as those from many Ascomycetes (Didymella) and Basidiomycetes (Ganoderma), are released into the atmosphere by processes related to humidity conditions or rain. The highest concentrations of ‘dry’ spores were observed early in the afternoon, while highest values of ‘wet’ spore concentrations occurred in the predawn hours. Statistically non-significant differences between daily spore concentrations in dry and rainy periods of single seasons were found except for Alternaria. Statistically significant differences could occur when the studied period was longer than one season (Alternaria, Didymella, Ganoderma). The highest concentrations of Alternaria, Botrytis and Cladosporium spores were recorded at noon and early in the afternoon. Concentrations of Didymella and Ganoderma spores were highest in the predawn hours.  相似文献   

6.
This paper presents the advances made over the last decade in cryopreservation of economically important vegetatively propagated fruit trees. Cryopreservation protocols have been established using both dormant buds sampled on field-grown plants and shoot tips sampled on in vitro plantlets. In the case of dormant buds, scions are partially dehydrated by storage at − 5 °C, and then cooled slowly to − 30 °C using low cooling rates (c.a. 1 °C/h) before immersion in liquid nitrogen. After slow rewarming and rehydration of samples, regrowth takes place either through grafting of buds on rootstocks or excision of apices and inoculation in vitro. In the case of shoot tips of in vitro plantlets, the cryopreservation techniques employed are the following: controlled rate cooling procedures involving slow prefreezing followed by immersion in liquid nitrogen or vitrification-based procedures including encapsulation–dehydration, vitrification, encapsulation–vitrification and droplet-vitrification. The current status of cryopreservation for a series of fruit tree species including Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis is presented. Routine application of cryopreservation for long-term germplasm storage in genebanks is currently limited to apple and pear, for which large cryopreserved collections have been established at NCGRP, Fort Collins (USA), using dormant buds and in vitro shoot tips, respectively. However, there are a growing number of examples of pilot scale testing experiments under way for different species in various countries. Progress in the further development and application of cryopreservation techniques will be made through a better understanding of the mechanisms involved in the induction of tolerance to dehydration and cryopreservation in frozen explants.  相似文献   

7.
The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.  相似文献   

8.
The genes encoding the ApaLI (5′-G^TGCAC-3′), NspI (5′-RCATG^Y-3′), NspHI (5′-RCATG^Y-3′), SacI (5′-GAGCT^C-3′), SapI (5′-GCTCTTCN1^-3′, 5′-^N4GAAGAGC-3′) and ScaI (5′-AGT^ACT-3′) restriction-modification systems have been cloned in E.␣coli. Amino acid sequence comparison of M.ApaLI, M.NspI, M.NspHI, and M.SacI with known methylases indicated that they contain the ten conserved motifs characteristic of C5 cytosine methylases. NspI and NspHI restriction-modification systems are highly homologous in amino acid sequence. The C-termini of the NspI and NlaIII (5′-CATG-3′) restriction endonucleases share significant similarity. 5mC modification of the internal C in a SacI site renders it resistant to SacI digestion. External 5mC modification of a SacI site has no effect on SacI digestion. N4mC modification of the second base in the sequence 5′-GCTCTTC-3′ blocks SapI digestion. N4mC modification of the other cytosines in the SapI site does not affect SapI digestion. N4mC modification of ScaI site blocks ScaI digetion. A DNA invertase homolog was found adjacent to the ApaLI restriction-modification system. A DNA transposase subunit homolog was found upstream of the SapI restriction endonuclease gene. Received: 15 April 1998 / Accepted: 3 August 1998  相似文献   

9.
Two isomers (R,S,R,S- and R,R,S,S-) of five coordinate complex [Cu(L)Cl]+ have been separated and characterised. These two isomers have significantly different spectrochemical and electrochemical properties. Absorption maximum of R,S,R,S-[Cu(L)Cl]+ shifts to longer wavelength and its reduction potential shifts to more positive direction comparing those of R,R,S,S-[Cu(L)Cl]+. R,S,R,S-[Cu(L)Cl]+ is significantly distorted to trigonal-bipyramidal structure, whereas R,R,S,S-[Cu(L)Cl]+ retains almost square-planar geometry. The average bond distance of Cu-N in basal plane of R,S,R,S-[Cu(L)Cl]+ is longer by 0.024 Å than that of R,R,S,S-[Cu(L)Cl]+, whereas the bond distance of Cu-Cl in former is shorter by 0.200 Å than that in latter. The isolated square-planar complexes of R,R,S,S- and R,S,R,S-[Cu(L)](ClO4)2 are converted to the R,R,S,S- and R,S,R,S-[Cu(L)Cl]+ by the addition of Cl in nitromethane solution with the rate constants, k=1.70 (±0.02) and 8.31 (±0.07) M−1 s−1, respectively.  相似文献   

10.
Glycosyltransferase family14 (GT14) belongs to the glycosyltransferase (GT) superfamily that plays important roles in the biosynthesis of cell walls, the most abundant source of cellulosic biomass for bioethanol production. It has been hypothesized that DUF266 proteins are a new class of GTs related to GT14. In this study, we identified 62 GT14 and 106 DUF266 genes (named GT14-like herein) in Arabidopsis, Oryza, Populus, Sorghum and Vitis. Our phylogenetic analysis separated GT14 and GT14-like genes into two distinct clades, which were further divided into eight and five groups, respectively. Similarities in protein domain, 3D structure and gene expression were uncovered between the two phylogenetic clades, supporting the hypothesis that GT14 and GT14-like genes belong to one family. Therefore, we proposed a new family name, GT14/GT14-like family that combines both subfamilies. Variation in gene expression and protein subcellular localization within the GT14-like subfamily were greater than those within the GT14 subfamily. One-half of the Arabidopsis and Populus GT14/GT14-like genes were found to be preferentially expressed in stem/xylem, indicating that they are likely involved in cell wall biosynthesis. This study provided new insights into the evolution and functional diversification of the GT14/GT14-like family genes.  相似文献   

11.
Of the 49 species of Solanum studied, cuscohygrine has been detected in 25, solamine and related amines in 17 and solamine-derived amides in 16. Five species of Cyphomandra examined all contained both amines and amides. From roots of Margaranthus solanaceus cuscohygrine has been isolated which probably occurs, too, in roots of Lycianthes rantonnettii. The distribution of these compounds throughout the taxa could be of chemotaxonomic value.  相似文献   

12.
ThelpA1/Gpcr26locus encodes the first cloned and identified G-protein-coupled receptor that specifically interacts with lysophosphatidic acid. A murine full-length cDNA of size consistent with that seen on Northern blots (3.7 kb) was determined using 3′ rapid amplification of cDNA ends. Analysis of genomic clones revealed that the gene is divided into five exons, with one intron inserted in the coding region for transmembrane domain VI and one exon encoding the divergent 5′ sequence in another published cDNA clone variant (orphan receptor mrec1.3). This structure differs from the intronless coding region for a homologous receptor,Edg1,but is identical to another more similar orphan receptor (lpA2) that has been deposited with GenBank. Using backcross analysis, both exons 1 and 4 mapped to a proximal region of murine Chromosome 4 indistinguishable from the vacillans gene. Exon 4 also mapped to a second locus on proximal Chromosome 6 inMus spretus,and this partial duplication was confirmed by Southern blot. The genomic structure indicates a distinct, divergent evolutionary lineage for thevzg-1/lpA1subfamily of receptors compared to those of homologous orphan receptor genes.  相似文献   

13.
Summary A case of 46,XY/45,X/46,XX mosaicism in a phenotypic intersex is decribed in detail. A few relevant aspects, which emerge especially from the phenotypic and karyotypic analysis, are briefly commented upon.
Zusammenfassung Es wird ein Fall von Mosaicismus 46,XY/45,X/46,XX beschrieben. Einige Aspekte, die aus der phänotypischen und karyotypischen Analyse des Patienten hervorgehen, sind kurz kommentiert.
  相似文献   

14.
A cladistic analysis was conducted to test the monophyly of Eschweilera and Lecythis as well as to examine the relationships of these two genera and their close relatives Bertholletia and Corythophora. The study included 86 species, representing all four genera and covering the range of taxonomic and morphological variation in the genera. The data matrix included 49 parsimony-informative characters derived from vegetative, floral, fruit, and seed morphology and anatomy. The results based on the consensus of all most parsimonious trees indicate that Bertholletia, Corythophora, Eschweilera, and Lecythis form a clade supported by brachyparacytic stomata, the absence of pedicels (with subsequent reversals in several clades), a two or four-locular ovary, the presence of an aril, and the absence of cotyledons. Within the clade, the monophyly of Corythophora is supported by the presence of inflorescence scales and the absence of nectar. Eschweilera is monophyletic only if E. congestiflora and E. simiorum are excluded. The monophyly of Eschweilera is supported by the presence of a two-locular ovary. Lecythis is not monophyletic, but sections Corrugata, Pisonis, and Poiteaui are monophyletic. Three species of section Lecythis are more closely related to Eschweilera, and other species of section Lecythis along with Bertholletia excelsa remain as unresolved.  相似文献   

15.
Starch grains are a ubiquitous component of plants that have been used in tandem with phytoliths, pollen, and macrofossils to reconstruct past floral diversity. This tool has yet to be fully explored for aquatic plants, specifically seagrasses, which lack phytoliths and are rarely preserved as macrofossils or pollen. If starch grains in seagrasses are morphologically distinct, this method has the potential to improve seagrass identification in the fossil record in such cases where its starch is preserved (e.g. scratches and occlusal surfaces of tooth enamel from seagrass consumers). The goals of this study were twofold: (1) to determine if starch is present in seagrass material and (2) to assess how starch grain morphology differs between different seagrasses.This study focused on four abundant and ecologically distinct seagrasses from the Caribbean: Halodule wrightii, Ruppia maritima, Syringodium filiforme, and Thalassia testudinum. Starch grains were observed in all species except S. filiforme. Grains from H. wrightii are typically observed in side-on orientation, are sub-round to angular, and are fairly small (3-19 μm, end-on). Grains of R. maritima are small spherical grains (4-8 μm) that have a centric hilum and a straight extinction cross with a median angle between the arms of 90°. Grains from T. testudinum are large (9-31 μm, end-on), conical in side-on and round/sub-round in end-on orientation, have a slightly eccentric hilum with an obvious particle, and prominent lamellae.Visual assessment and comparative statistics demonstrate that the morphology of starch grains from T. testudinum, R. maritima, and H. wrightii are significantly different. With more extensive research, there is potential for the positive identification of starch grains from an unknown seagrass. The ability to identify seagrass from starch grains could facilitate the identification of seagrasses in the fossil record and supply information on seagrass evolution and distribution, climate effects on seagrass distribution, and the diets of seagrass consumers.  相似文献   

16.
The repellent activity of alligator pepper, Aframomum melegueta, and ginger, Zingiber officinale (Zingiberaceae), against the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae), was investigated in four-way olfactometer bioassays. Results showed that vacuum distilled A. melegueta and Z. officinale extracts were repellent towards adult S. zeamais both in the absence and the presence of maize, Zea mays, grains. Bioassay-guided liquid chromatographic fractionation of the distillates showed that fractions containing oxygenated compounds accounted for the repellent activity. Coupled gas chromatography-mass spectrometry (GC-MS), followed by GC peak enhancement and enantioselective GC using authentic compounds, identified 3 major compounds in the behaviourally active fractions of A. melegueta and Z. officinale to be (S)-2-heptanol, (S)-2-heptyl acetate and (R)-linalool in a ratio of 1:6:3, and 1,8-cineole, neral and geranial in a ratio of 5.48:1:2.13, respectively. The identification of these behaviourally active compounds provides the scientific basis for the observed repellent properties of A. melegueta and Z. officinale, and demonstrates the potential for their use in stored-product protection at the small-scale farmer level in Africa.  相似文献   

17.
In order to investigate the relationship existing between the electronic structures of collagen and its biochemical functions in vivo, the semiempirical CNDO/2 SCF MO calculations were carried out on several model polymers of collagen, (Gly-Pro)n, (Gly-Hyp)n, (Ala-Pro)n, (Ala-Hyp)n, (Gly-Pro-Gly)n, (Gly-Hyp-Gly)n, (Gly-Pro-Pro)n and (Gly-Pro-Hyp)n. Geometries of the skeleton of these polymers were assumed to be the same as those of poly(l-proline) I (cis) and II (trans) and the calculations were performed only on infinite polymers in a single chain. The results show that the cis form is always more stable than the trans form for all the polymers treated. This energy difference between the cis and trans forms depends, for example, on the kind of amino acid residue, Gly or Ala, but this could not be seen in the Pro or Hyp residue. The flexibility or mobility of the collagen structure was explained using the energy difference between the cis and trans forms of the polymers, i.e. the cis-trans conversion of the collagen was discussed in connection with the energy difference. The reason why the collagen has the constitution of (Gly-Pro-Hyp)n is briefly discussed.  相似文献   

18.
The new genus and species Teracosphaeria petroica is described for a perithecial ascomycete and its anamorph occurring on decayed wood collected in New Zealand. The fungus produces immersed, non-stromatic ceratosphaeria-like perithecia in nature, with hyaline, septate ascospores produced in unitunicate, non-amyloid asci. The anamorph produced in vitro is phialophora-like with lightly pigmented phialides terminating in flaring, deep collarettes that are often noticeably brown with conspicuous periclinal thickening. Phylogenetic analysis of LSU rDNA sequence data indicates that this fungus is distinct from morphologically similar fungi classified in the Chaetosphaeriales, the Trichosphaeriales or the Magnaporthaceae. It forms a monophyletic group with recently described, chaetosphaeria-like ascomycetes, such as the pyrenomycete genus Mirannulata, and shows affinity with the anamorphic species Dictyochaeta cylindrospora. The usefulness of describing anamorph genera for morphologically reduced anamorphs, when anamorph characteristics are actually part of the holomorph diagnosis, is discussed. An apparently contradictory example of the so-called Cordana and Pseudobotrytis anamorphs of Porosphaerella spp. is also discussed.  相似文献   

19.
糖基转移酶广泛存在于植物中,其中UDP依赖型糖基转移酶(UDP-glycosyltransferases,UGTs)基因家族是糖基转移酶中的一大类。该研究以华南124木薯品种(Manihot esculenta cv.SC124)为材料,利用RT-PCR技术克隆木薯MeUGT41基因,以病毒诱导干扰木薯MeUGT41基因的表达量,并对基因干扰植株进行细菌性枯萎病抗性评价,为研究MeUGT41基因在木薯抵抗细菌性枯萎病的抗病机理奠定基础。结果表明:(1)地毯草黄单胞菌(Xamthomonas axonopodis pv.Manihotis,Xam)可显著诱导木薯MeUGT41基因表达。(2)成功构建MeUGT41的病毒诱导基因沉默(VIGS)载体,将干扰载体转化至木薯叶片进行MeUGT41基因沉默,荧光定量PCR检测结果显示,木薯叶片中MeUGT41基因的表达量显著下降。(3)Xam侵染实验表明,干扰抑制MeUGT41基因表达可显著降低木薯植株叶片对Xam病菌侵染的抵抗能力。研究认为,木薯叶片中MeUGT41基因具有抵抗Xam病菌侵染的能力。  相似文献   

20.
Zusammenfassung Es wird über ein 7jähriges Mädchen berichtet, bei dem im Mosaik Zellen mit Trisomie 21, Monosomie X und normalem weiblichem Karyotyp gefunden wurden. Klinisch bot die Patientin das abgeschwächte Erscheinungsbild des Mongolismus. Die für das Turner-Syndrom typischen äußeren Veränderungen traten demgegenüber zurück.
Summary A 7 year old girl is found to have a chromosome mosaic of trisomy 21, monosomy X, and normal female karyotype. The patient showed some clinical symptoms of mongolism, whereas Turner-stigmata were less obvious.
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