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1.
Background: Allergy to Prunoideae fruit (plum, peach, cherry and apricot) is one of the most frequent food allergies in southern Europe. All these fruits cross-react in vivo and in vitro, as they share their major allergen, a 9 kD lipid transfer protein (LTP). Objective: The aim of the study was the identification and molecular characterization of the major allergen of plum. Methods: The IgE pattern of reactivity to plums was investigated by SDS–PAGE and immunoblotting with the sera of 23 patients. The identified major allergen was purified by HPLC, using a cationic-exchange column followed by gel-filtration. Further characterization was achieved by periodic-Schiff stain, isoelectrofocusing and N-terminal amino acid sequencing. Results and conclusions: The major allergen of plum is a 9 kD lipid transfer protein, not glycosylated and with a basic character (pI>9), highly homologous to the major allergen of peach.  相似文献   

2.
The cellulase from Geoscapheus dilatatus consisted of two major and four minor endo-β-1,4-glucanase components. Two major and one minor component were purified to homogeneity. The major endo-β-1,4-glucanase components, named GD1 and GD2, were similar to EG1 and EG2 from Panesthia cribrata in terms of Mr and kinetic properties. The purified minor component, named GD3, was distinct from GD1 and GD2 because of a lower Mr and a lower specific activity. Polyclonal antibodies raised against the two major endo-β-1,4-glucanase components, EG1 and EG2, of the cellulase from P. cribrata cross-reacted with each other and with pure GD1 and GD2 from the foregut and midgut of the related cockroach G. dilatatus but did not cross-react with GD3. Endo-β-1,4-glucanase components were partially purified from the foregut and midgut of four other cockroaches. These comprised three other Australian cockroaches also from the superfamily Blaberoidea and one American cockroach, Cryptocercus punctulatus, from the superfamily Blattoidea. The endogenous cellulases from all cockroaches examined consisted of either two or three major endo-β-1,4-glucanase components. The amino acid sequence of the N-terminus region of the two major endo-β-1,4-glucanase components from P. cribrata were determined and are homologous with those belonging to glycosyl hydrolase family 9 (cellulase family E).  相似文献   

3.
Growth of Plantago major L., ssp. major L. and ssp. pleiosperma Pilger and P. maritime L. was followed at two levels of mineral nutrition (low-salt and high-salt). In addition the response of transfer of plants from low-salt conditions to high-salt conditions and vice versa was studied. Growth of the studied Plantago species was strongly stimulated by high-salt conditions. The Ca2+- and Mg2+-stimulated ATPase activity of microsomal preparations of the roots was also studied. In P. major ssp. major and P. maritime a major pH optimum was observed at pH 6.5, and in addition a second pH optimum was found at pH 8.0. High-salt plants of these two species were characterized by biphasic stimulation curves for Ca2+ and Mg2+, whereas P. major ssp. pleiosperma showed a monophasic pattern. The ATPase activity per g dry weight of P. major and P. maritima was highest in high-salt plants. The species investigated here are adapted to relatively nutrient-rich conditions, and the properties of ATPases (Km, Kmax, protein content) and the growth responses are discussed in relation to this ecological property.  相似文献   

4.
Summary An ascomycete Monocillium indicum Saxena producing extracellular laccase was isolated. The culture filtrate on native polyacrylamide gel electrophoresis (PAGE) revealed four bands of activity, one of which was a major one. The major laccase band, a glycoprotein, was purified and characterized. Gel filtration chromatography showed that the relative molecular weight (Mr) of laccase was 100 000. On sodium dodecyl sulphate (SDS)-PAGE the major laccase band further resolved into three proteins of Mr 72 000, 56 000 and 24 000. The enzyme had a pH optimum of 3.0 and was active on a number of o-phenols and aromatic acids. The 72 000 Mr protein was found to share common immunological properties with laccases of Coriolus versicolor, Agaricus bisporus and lignin peroxidase of Phanerochaete chrysosporium. Correspondence to: K. Koteswara Rao  相似文献   

5.
The ecology of the aquatic gastropods Bithynia tentaculata, Gyraulus albus, Planorbis planorbis and Lymnaea peregra in North West England was investigated over 13 months at sites chosen for their wide range of water chemistry. Multiple regression analysis was used to determine the significance to the mollusc distributions of a variety of physico-chemical factors. Biotic factors were not considered. The species had similar life cycles, with little difference between populations within a species. B. tentaculata could live for over a year, and the major water chemistry variable was potassium (+), where the sign is that of the regression coefficient. G. albus could also survive into a second year and the major variable was mud substratum type (+). Rock substratum type (-) was the most important factor for P. planorbis. There was a slight difference in the life cycles of L. peregra in hard and medium compared with soft waters and the major water chemistry variable was magnesium (-).  相似文献   

6.
Two mucins were isolated from bovine submandibular glands and termed major and minor on a quantitative basis. The major mucin representing over 80% of the total glycoprotein fraction contained 37% of its dry weight as protein in contrast to 62% for the minor mucin. Differences in the amino acid composition reflected the higher proportion of typically non-glycosylated peptide in the minor mucin. The molar ratio ofN-acetylgalactosamine to serine plus threonine was 0.82 in major and 0.65 in minor mucins, indicating a lower degree of substitution of potential glycosylation sites in the minor mucin.Differences in the carbohydrate composition were found largely related to the sialic acids, with higher relative amounts ofN-glycoloylneuraminic acid in the minor mucin. In addition, the proportion of di-O-acetylated sialic acids was higher in the major mucin. The rate of sialidase action on the two mucins could be correlated with the content ofN-glycoloylneuraminic acid in each glycoprotein. There was no difference in the type of oligosaccharide found in each mucin and the differences in relative proportions reflected the monosaccharide composition for the two mucins. Gel filtration on Sepharose CL 2B showed a lower molecular weight distribution for the minor in contrast to the major mucin which was partially excluded. Density gradient centrifugation reflected this variation. SDS-PAGE demonstrated a regular banding pattern for the major mucin with a lowest subunit size of 1.8×105 Da and aggregates in excess of 106 Da, while the minor mucin ranged from 3.0 × 105 to 106 Da. The chemical composition of the isolated mucins was compared with previous histochemical analysis of mucin distribution in bovine submandibular glands and indicates a possible cellular location for each mucin.Abbreviations PBS 0.01m sodium phosphate buffer, pH 7.3, containing 0.15m NaCl - Neu5Ac N-acetylneuraminic acid - Neu5Gc N-glycoloylneuraminic acid - GalNAc-ol N-acetylgalactosaminitol  相似文献   

7.
The carotenoids of 4 species of blue-green algae, Anabaena variabilis, Phormidium persicinum, P. ectocarpi, and P. fragile, were investigated. In each, ft-carotene was a major pigment and the only carotene detected. The xanthophylls present in Anabaena variabilis were echinenone, canthaxanthin, and myxo-xanthophyll. Each of the Phormidium species contained zeaxanthin as the major xanthophyll. In each, this was accompanied by trace amounts of echinenone and isocryptoxanthin. In addition, 2 new xanthophylls, spectrally resembling ^-carotene, were found in Phormidium persicinum and P. ectocarpi, while another, with a spectrum similar to that of myxoxanthophyll, was found in P. fragile.  相似文献   

8.
Apparent amylose content (AAC), gel consistency (GC), and gelatinization temperature (GT) are recognized as the most important determinants of rice eating and cooking qualities. The contributions of major starch-synthesis genes to these three traits have been investigated in the three consecutive experiments. In an initial QTL mapping with 130 doubled haploid (DH) lines, derived from an inter-subspecific cross of ‘Nanjing11’/‘Balilla’, the major QTLs responsible for AAC, GC, and GT coincided with the Wx (granule-bound starch synthase gene), Wx, and Sss IIa (soluble starch synthase gene) loci, respectively. In the second experiment, contributions of the major starch-synthesis genes to AAC, GC, and GT variations were estimated by using a multiple linear regression analysis. As shown, the Wx locus was a principal determinant for both AAC and GC, and could account for 58.5% and 38.9% of the phenotypic variations, respectively; while the Sss IIa locus was associated with GT, and could explain 25.5% of the observed variation. Eventually, a F2 population consisting of 501 individuals, derived from an inter-subspecific cross of the two sticky rice varieties ‘Suyunuo’ and ‘Yangfunuo 4’, was examined with gene-tagged markers. In the absence of the Wx gene, none of the starch-synthesis genes investigated could dominate the GC variation, however, the Sss IIa locus could also explain 25.1% of the GT variation. In summary, the Wx locus dominates the AAC variation, and meanwhile plays a major role in the GC variation. The Sss IIa locus is a major factor in explaining the GT variation. Apart from the major genes, other genetic factors may also contribute to the GC/GT variations.  相似文献   

9.
Objective: To test the hypothesis that major depression predicts an increase in long‐term body weight variability (BWV). Research Methods and Procedures: This was a prospective community‐based single‐age cohort study of young adults (N = 591) followed between the ages of 19 and 40. Following initial screening, information was derived from six subsequent semistructured diagnostic interviews conducted by mental health professionals. Major depression was diagnosed on the basis of DSM criteria. BWV was defined as the root mean square error of a regression line fitted to each individual's BMI values over time. Multiple regression analysis was used to test the association between major depression and BWV while controlling for potentially confounding variables including antidepressant treatment, eating disorder symptoms, and physical activity. We used random effects models to determine the temporal relationship between repeated measures of major depression and body weight change. Results: A highly significant positive association between major depression and BWV was found, whereas major depression was not associated with BMI level or BMI trend. Depression severity showed a dose‐response‐type relationship with the magnitude of BWV. After controlling for potentially confounding variables including antidepressant use, eating disorder symptoms, smoking, and physical activity, major depression remained a significant predictor of BWV (β= 0.13, p < 0.001). Longitudinal analysis revealed a unidirectional association between major depression and a later increase in body weight change rate irrespective of antidepressant medication. Discussion: Results from this study implicate depression as an important risk factor for increased BWV. Given increasing evidence for a link between major depression and both diabetes and cardiovascular disease, current results encourage further research on depression, BWV, and negative health outcomes.  相似文献   

10.
Heading date 1 (Hd1) is an important gene for the regulation of flowering in rice, but its variation in major cultivated rice varieties, and the effect of this variation on yield and quality, remains unknown. In this study, we selected 123 major rice varieties cultivated in China from 1936 to 2009 to analyse the relationship between the Hd1 alleles and yield‐related traits. Among these varieties, 19 haplotypes were detected in Hd1, including two major haplotypes (H8 and H13) in the japonica group and three major haplotypes (H14, H15 and H16) in the indica group. Analysis of allele frequencies showed that the secondary branch number was the major aimed for Chinese indica breeding. In the five major haplotypes, SNP316(C‐T) was the only difference between the two major japonica haplotypes, and SNP495(C‐G) and SNP614(G‐A) are the major SNPs in the three indica haplotypes. Association analysis showed that H16 is the most preponderant allele in modern cultivated Chinese indica varieties. Backcrossing this allele into the japonica variety Chunjiang06 improved yield without decreasing grain quality. Therefore, our analysis offers a new strategy for utilizing these preponderant alleles to improve yield and quality of japonica varieties for cultivation in the southern areas of China.  相似文献   

11.
Summary Chromosome 5A of bread wheat, Triticum aestivum carries the major gene, Vrnl, which is one of the main determinants of the winter/spring growth habit polymorphism in this species. Genetical analysis of this chromosome has been carried out using single-chromosome recombinant lines to establish the pleiotropic effects of this locus and two other major genes, q determining ear morphology and bl determining the presence of awns, on important agronomic characters. The three major genes were located on the long arm of chromosome 5A with a gene order of: centromere -bl-q-Vrnl. Analysis of quantitative characters from a winter sowing revealed pleiotropic effects of Vrnl or the effects of closely linked loci on the characters plant height, tiller number and spikelet number. However effects on ear emergence time were not associated with Vrnl but with q as were effects on spikelet number and ear length. In addition a locus determining yield/plant was located between Vrnl and q. Independant loci determining height and ear length were apparent on the short arm of chromosome 5A. From a spring sowing, however, there was a large pleiotropic effect of Vrnl on ear emergence time, as well as the effects previously detected. In addition, associated with q were effects on plant height and grain size which were not expressed from the winter sowing.  相似文献   

12.
Three major hemolymph proteins of Papilio polyxenes larvae were isolated and characterized. Density gradient ultracentrifugation of hemolymph resulted in flotation of the major lipoprotein, lipophorin. P. polyxenes larval lipophorin is composed of two apoproteins, apolipophorin-I and apolipophorin-II, plus a mixture of lipids, to give a density of 1.13 g/ml. Immunoblotting experiments using antisera directed against Manduca sexta apolipophorin-I and apolipophorin-II, respectively, revealed cross-reactivity of apoLp-I with Manduca sexta apoLp-I, and apoLp-II with M. sexta apoLp-II. Gel permeation chromatography of the subnatant obtained following density gradient ultracentrifugation revealed the presence of a major protein peak which was shown to contain three major serum proteins, two of which were isolated and characterized. One of these proteins was purified by lectin affinity chromatography. Both proteins have native molecular weights in the range of 450,000 and appear to be hexamers of a single subunit type. Major serum protein-1 is nonglycosylated and has a subunit molecular weight of 75,000. Major serum protein-2 is glycosylated and has a subunit molecular weight of 74,000. Amino acid analysis of this protein revealed a tyrosine plus phenylalanine content of 20 mole percent, characteristic of the arylphorin class of insect storage proteins. Using antibodies against M. sexta larval hemolymph proteins, both the P. polyxenes major serum proteins were shown to be immunologically related to serum proteins of other lepidopteran species.  相似文献   

13.
Selected strains of Candida albicans were examined to reveal the surface antigenicity and biochemical nature of major cell wall proteins that also were shown to serve as cellular adhesins on human buccal epithelial cells. Confirmation of the adhesive properties of these cells was made by scanning electron microscopy and immunofluorescence microscopy. Particular attention was directed at the clinical isolate KM-302. By means of indirect immunofluorescence staining, the KM-302 blastoconidia absorbed rabbit anti-C. albicans ATCC-32354 serum, revealing specific localization of surface antigens on germ tubes and pseudohyphae. Extracellular polymeric material and the cell wall extract of C. albicans KM-302 blastoconidia were found to contain a major surface antigen of 49 kDa that exhibited 42% adhesion inhibition in vitro. Of considerable significance is that immunogold localization by electron microscopy showed the antigen to be almost exclusively cell wall bound. This major antigen, identified in affinity and gel filtration chromatography fractions, was composed of 4% carbohydrate and 95.7% protein and had an isoelectric point of 6.1. The major antigen also showed a high level of similarity with that of C. albicans strain SC-5314 inasmuch as the major antigen of that strain had carbohydrate and protein compositions of 4 and 95.5%, respectively. Both of these strains also possessed the same percent of adhesion inhibition of human buccal epithelial cells.Abbreviations BECs buccal epithelial cells - CWE cell wall extract - EPP extracellular polymers and proteins - FITC fluorescein isothiocyanate - mAg major antigen - OD 600 optical density at 600 nm - PBS phosphate buffered saline - TEM transmission electron microscopy - YNB yeast nitrogen base  相似文献   

14.
北京河流底栖硅藻沿城乡梯度带空间分布及其季节变化   总被引:2,自引:0,他引:2  
陈向  周伟奇  李伟峰 《生态学报》2017,37(10):3586-3595
研究了北京市区沿城乡梯度带河流底栖硅藻的空间分布及其季节变化特征。通过在2014年的春季、夏季和秋季在山区对照溪流、城市上游河道和城市下游河道3个样区,共23个样点进行了底栖硅藻样品采集。分析表明,主要优势种的空间差异明显。在对照溪流,主要优势种为极小曲丝藻(Achnanthidium minutissimum);在城市上游河道,主要优势种分别为短文假十字脆杆藻(Pseudostaurosira brevistriata)和连结十字脆杆藻腹面变种(Staurosira construens var.venter);在城市下游河道,主要优势种为谷皮菱形藻(Nitzschia palea)。然而,3个样区内的主要优势种相对丰度季节变化较小(P0.05)。其中,A.minutissimum及P.brevistriata的季节变化特征均为春季秋季夏季,而S.construens var.venter及N.palea的季节变化特征均为春季夏季秋季。结果发现,北京市城乡梯度带的河流硅藻种类组成差异较大,但主要优势属种季节变化相对较小,表明硅藻种类能较好地反映城乡梯度带的河流环境变化状况,可用于北京市河流水质生物监测。  相似文献   

15.
In 96 patients with congenital adrenal hyperplasia (CAH) and 50 healthy donors from northwestern Russia the distribution of the HLA-DQA1 alleles and the mutation spectrum and frequency at the CYP21B gene were examined. In the patients with nonclassical (NC) CAH, the distribution of the HLA-DQA1 polymorphic alleles was similar to that in the population sample. In the patients with the salt-wasting form of the disease a statistically significant decrease of the *0401 or *0501major allele frequency was observed. The prevalence of certain HLA-DQA1 genotypes, namely, HLA5, HLA3, and HLA4, was observed in the patients with the NC, salt-wasting (SW), and simple virilizing CAH, respectively. Each clinical group was characterized by a specific spectrum of clinically valuable mutations. An association between theCYP21B mutations most frequently found in case of SW and SV CAH (delB, I2splice, and I172N) and certain HLA-DQA1alleles was demonstrated. The necessity of more precise clinical diagnostics of the NC CAH cases along with detailed examination of this group for determination of the major mutations typical of the NC CAH cases from northwestern Russia is discussed.  相似文献   

16.
17.
The Island of Borneo is a major biodiversity hotspot, and in the Malaysian state of Sabah, ultramafic soils are extensive and home to more than 31 endemic nickel hyperaccumulator plants. The aim of this study was to characterize the structure and the diversity of the rhizosphere bacterial communities of several of these nickel hyperaccumulator plants and factors that affect these bacterial communities in Sabah. The most abundant phyla were Proteobacteria, Acidobacteria and Actinobacteria. At family level, Burkholderiaceae and Xanthobacteraceae (Proteobacteria phylum) were the most abundant families in the hyperaccumulator rhizospheres. Redundancy analysis based on soil chemical analyses and relative abundances of the major bacterial phyla showed that abiotic factors of the studied sites drove the bacterial diversity. For all R. aff. bengalensis rhizosphere soil samples, irrespective of studied site, the bacterial diversity was similar. Moreover, the Saprospiraceae family showed a high representativeness in the R. aff. bengalensis rhizosphere soils and was linked with the nickel availability in soils. The ability of R. aff. bengalensis to concentrate nickel in its rhizosphere appears to be the major factor driving the rhizobacterial community diversity unlike for other hyperaccumulator species.  相似文献   

18.
The A1 cytoplasmic–nuclear male sterility system in sorghum is used almost exclusively for the production of commercial hybrid seed and thus, the dominant genes that restore male fertility in F1 hybrids are of critical importance to commercial seed production. The genetics of fertility restoration in sorghum can appear complex, being controlled by at least two major genes with additional modifiers and additional gene–environment interaction. To elucidate the molecular processes controlling fertility restoration and to develop a marker screening system for this important trait, two sorghum recombinant inbred line populations were created by crossing a restorer and a non-restoring inbred line, with fertility phenotypes evaluated in hybrid combination with three unique cytoplasmic male sterile lines. In both populations, a single major gene segregated for restoration which was localized to chromosome SBI-02 at approximately 0.5 cM from microsatellite marker, Xtxp304. In the two populations we observed that approximately 85 and 87% of the phenotypic variation in seed set was associated with the major Rf gene on SBI-02. Some evidence for modifier genes was also observed since a continuum of partial restored fertility was exhibited by lines in both RIL populations. With the prior report (Klein et al. in Theor Appl Genet 111:994–1012, 2005) of the cloning of the major fertility restoration gene Rf1 in sorghum, the major fertility restorer locus identified in this study was designated Rf2. A fine-mapping population was used to resolve the Rf2 locus to a 236,219-bp region of chromosome SBI-02, which spanned ~31 predicted open reading frames including a pentatricopeptide repeat (PPR) gene family member. The PPR gene displayed high homology with rice Rf1. Progress towards the development of a marker-assisted screen for fertility restoration is discussed.  相似文献   

19.
Chloroplasts of a chlorophyll (Chl) b-less barley mutant were solubilized with digitonin and fractionated by polyacrylamide gel electrophoresis with sodium deoxycholate in the running buffer. By this procedure, in contrast to using sodium dodecylsulfate (SDS) for solubilization, a Chl a-protein analogous to the major light-harvesting Chl a-b protein complex from wildtype chloroplasts was recovered. This mutant Chl a-protein comprises about fifty percent of the total Chl a, and is very similar in carotenoid, amino acid, protein and polypeptide composition to the major wildtype antenna Chl a-b protein. The only major differences we have found is its instability in the presence of SDS and sensitivity to protease action. Even with deoxycholate, the mutant Chl a complex often dissociates during electrophoresis into two green bands. The lack of Chl b appears to affect the normal organization of Chl a and protein in such a way as to render the complex more unstable.CIW-DPB No. 917.  相似文献   

20.
The major sex pheromone compound of the spotted tentiform leafminer, Phyllonorycter blancardella (F.) (Lepidoptera: Gracillariidae), from Ontario, Canada, was identified as (10E)‐dodecen‐1‐yl acetate (E10‐12:Ac) using chemical analysis and field trapping experiments. The minor compounds (10E)‐dodecen‐1‐ol (E10‐12:OH) (4.6%), dodecan‐1‐ol (12:OH) (2.3%), and (10Z)‐dodecen‐1‐yl acetate (Z10‐12:Ac) 1.6% were also identified. The dienic acetate (4E,10E)‐dodecadien‐1‐yl acetate (E4,E10‐12:Ac), a compound reported to be attractive to P. blancardella, was not found in the glands of this population. A two‐component blend of the major and one of each the three minor compounds, in ratios similar to those found in the sex pheromone gland, did not increase the attractiveness of traps baited with synthetic pheromone. The minor compounds E10‐12:OH and 12:OH were not attractive to P. blancardella when tested individually. Z10‐12:Ac was attractive to P. blancardella, although traps baited with this compound captured only 2% of the moths that were captured in traps baited with the main compound. A four‐component blend of the major and each of the three minor compounds (100 : 1 : 1 : 1) was not more attractive than the major compound alone. The related species Phyllonorycter mespilella was captured in traps baited with E10‐12:Ac.  相似文献   

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