首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Aqueous extracts of two Ps. aeruginosa strains killed with acetone were subjected to fractionation by preparative ultracentrifugation and gel-chromatography. Toxic activity of the extract was found to be connected with the high-molecular, possibly glycoprotein components reacting with the corresponding antiserum in the immunoprecipitation test, and protecting 30--40% of rats against the generalized infection with Pseudomonas aeruginosa. This protective activity is apparently connected with the protein components (molecular weight--20000--60000 dalton), nontoxic for mice, not reacting with the corresponding antiserum in the immunoprecipitation test, and protecting 60 to 80% of rats against Ps. aeruginosa infecsion. Thus, as a result of preparative ultracentrifugation and gel-chromatography it was postible to divide the toxic and the nontoxic protective components of Ps. aeruginosa.  相似文献   

2.
In fractionation of Pseudomonas aeruginosa mucus (strains No. 8 and 1463) by means of diafiltration on the system of membranes Diaflo XM-300, XM-100A, PM-30, and PM-10 there was obtained a successive series of fractions differing by the molecular weight and chemical composition. According to the results of gel chromatography fractions with the mol wt of 100000 dalton and over apparently represented protein-polysaccharide components of mucus in the form of complexes; fractions with the mol wt of 30000 dalton and lower contained a considerable amount of free protein along with the protein-polysaccharide complex. The fractions obtained differed by biological properties: fractions with the mol wt of 100000 dalton and over were toxic for mice and possessed weak antigenic properties in the precipitation in agar test and immunoelectrophoresis; fractions with the mol wt lower than 30000 dalton expressed in the mentioned test distinct antigenic properties and proved to be practically nontoxic for mice. Thus the use of diafiltration method permitted to separate the antigenic, weakly toxic component of Ps. aeruginosa mucus from the toxic factor with weak antigenic properties.  相似文献   

3.
Various slime fractions were obtained from newly isolated mucoid strains of P. aeruginosa by the method of ultrafiltration or differential centrifugation with subsequent gel chromatography. Purified slime was found to react with a broader spectrum of typing O sera than the corresponding cell wall lipopolysaccharides. Erythrocytic diagnostic preparations produced on the basis of slime antigens allowed to reveale the presence of circulating antibodies against P. aeruginosa. The slime components with molecular weight of 30,000--100,000 daltons and greater contained common antigenic determinants, and the slime components with molecular weight of 10,000--30,000 daltons contained both specific antigenic determinants and those also common to the high molecular components.  相似文献   

4.
Edeine-synthesizing polyenzymes, associated with a complex of sytoplasmic membrane and DNA, were obtained from gently lysed cells of Bacillus brevis Vm4. The polyenzymes-membrane-DNA complex, isolated from dells intensively synthesizing edeines (18--20 h culture) contained edeine B. Edeine B was found to be bound covalently t o the edeine synthetase. The amount of edeine bound to polyenzymes was 0.1--0.3 mumol/mg protein, depending on the age of cells. Detachment of deeine synthetase with a covalently bound edeine B from the membrane-DNA complex was accomplished by a treatment with (NH4)2-SO4 at 45--55% saturation or by DEAE-cellulose column fractionation. In contrast to other components of the complex, the edeine-polyenzymes fragment was not adsorbed to the DEAE-cellulose. Sephadex G-200 column chromatography separated the edeine-polyenzymes complex into 3 fractions. Edeine-polyenzymes complex, obtained from lysozyme-Brij-58-DNAase treated cells, contained edeine B bound to two protein fractions of mol. wt 210 000 and 160 000. Edeine-polyenzymes complex detached from the complex with the membrane and DNA contained edeine B, bound only to protein fraction of mol. wt 210 000. Edeine A was not found in the edeine-polyenzymes complex. No accumulation of free antibiotics within 16--22 h old cells of B. brevis Vm4 was detected. The edeine-polyenzymes complex associated with the DNA-membrane complex has shown no antimicrobial activity. By treating of above with alkali, edeine B of specific activity: 80 units/mjmol was released. The complex of DNA-membrane associated with edeine-polyenzymes complex was able to synthesize DNA, under the conditions described for synthesis, directed by a DNA-membrane complex. Edeine when associated with this complex did not effect the DNA-synthesizing activity.  相似文献   

5.
Abstract In a murine model of Gram-negative sepsis, we have shown that the prophylactic application of human monoclonal antibodies (HmAbs) with specificity for lipopolysaccharides (LPS) of Pseudomonas aeruginosa protected against bacterial infection. In this paper we show that the therapeutical application of 5 μg of these HmAbs up to 6 h after challenge with a lethal dose of live P. aeruginosa results in a protection rate of 70–90%. Administration 18 h after bacterial challenge, diminished the protection to 43% survival rate. Furthermore, using a mixture of HmAbs recognizing a total of six different P. aeruginosa serotypes, no interference in their protective capacities was found. Finally, these HmAbs also protected galactosamine-sensitized mice against lethal challenge with LPS. Our data show that the described HmAbs confer bactericidal activity as well as anti-endotoxic activity in vivo.  相似文献   

6.
The possibility of using experimental culture medium K-4 prepared on the basis of casein hydrolysate peptides with the isoelectric point 4.1 for obtaining antigens from P. aeruginosa strains was evaluated. Two antigenic fractions were isolated from the culture fluid containing extracellular slime. The study of the toxicity of the antigenic preparations revealed that one of these fractions had low toxicity for mice (the second antigenic fraction was highly toxic). The former P. aeruginosa antigenic fraction was used for obtaining pyocyanic vaccine. One vaccination dose of this vaccine contained 0.2 mg of the antigen adsorbed on aluminum hydroxide. Pyocyanic vaccine ensured the active protection of mice challenged with P. aeruginosa homologous and heterologous strains.  相似文献   

7.
Protective antigens of rodent and human bloodstage malaria   总被引:8,自引:0,他引:8  
Bloodstage malaria parasites are antigenically complex, but individual antigens can be identified and analysed using monoclonal antibodies. Two monoclonal antibodies that recognize a 235 000 molecular mass Plasmodium yoelii rhoptry protein provide some protection when injected into mice against a challenge infection. The purified rhoptry protein also provides protective immunity against P. yoelii YM when used to vaccinate mice and fulminating infections are converted into self-limiting, reticulocyte-restricted infections. Another monoclonal antibody immunoprecipitates a 230 000 molecular mass protein and a series of proteolytic processing fragments. At least one of these processing fragments, probably a 90 000 molecular mass species, is located on the merozoite surface. Mice immunized with the purified protein were protected against challenge infection with P. yoelii YM. This antigen may provide protection by inducing a cell-mediated immune response. A monoclonal antibody raised against P. falciparum schizonts reacts with a 195 000 molecular mass protein which is synthesized in schizonts and subsequently cleaved. Fragments of the 195 000 molecular mass protein are expressed as major antigens on the merozoite surface. The 195 000 molecular mass P. falciparum protein and the 230 000 molecular mass P. yoelii protein belong to a class of malaria parasite antigens which probably is important in the induction of a protective immune response in the host.  相似文献   

8.
Rat liver mitochondria were fractionated into inner and outer membranes and soluble intermembrane space and matrix. The protein components of these fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mitochondria contained at least 20 components ranging in molecular weights from 10 000 to 140 000. Inner membranes differed markedly from outer membranes both in number of components and size distribution. The intermembrane space contained a few polypeptide species. These were of low molecular weight. The matrix was characterized by a high molecular weight component (130 000) which comprised 30% of this fraction. A major carbohydrate-containing polypeptide with an approximate molecular weight of 93 000 was detected in outer membrane preparations.  相似文献   

9.
Purinergic receptors are expressed throughout the respiratory system in diverse cell types. The efficiency of mucus clearance in the airways, the cascade leading to tissue injury, and inflammation are modulated by autocrine/paracrine release of nucleotides and signaling by purinergic receptors. We assessed the role of purinergic receptors in innate host defense of the lung in vivo by infecting mice deficient in P2Y1, P2Y2, or both receptors with intratracheal instillation of Pseudomonas aeruginosa. After P. aeruginosa challenge, all double knockout (P2Y1/P2Y2-/-) mice succumbed within 30 h of challenge, whereas 85% of the wild-type mice survived. Thirty-three percent of wild-type mice survived beyond 96 h. Single knockout mice, P2Y1-/-, or P2Y2-/-, exhibited intermediate survivals. Twenty-four hours following intratracheal instillation of a sublethal dose of P. aeruginosa, the level of total protein in bronchoalveolar lavage fluid was 1.8-fold higher in double knockout than in wild-type mice (P < 0.04). Total cell count in bronchoalveolar lavage fluids at 4 h and levels of IL-6 and macrophage inflammatory protein-2 in lung homogenates at 24 h postchallenge were significantly reduced in P2Y1/P2Y2-/- mice relative to wild-type mice. These findings suggest that purinergic receptors exert a protective role against infection of the lungs by P. aeruginosa by decreasing protein leak and enhancing proinflammatory cytokine response.  相似文献   

10.
Humic-like substances obtained from cells of Pseudomonas acidovorans were separated on Sephadex G-25 into two groups of substances of different molecular weight. The substances of the molecular weight greater than 5000 were successively separated on Sephadex gels G-50, G-75, G-100. Five fractions of different molecular weight were obtained, the percentage of which varied depending on the media used and time of incubation of the bacteria. Most (38%--46%) of the compounds contained in the bacterial humic acids were of approximate molecular weight of 40 000--50 000. The distribution of the fractions in the bacterial "humic-acids" was compared with those of the humic acid made by Fluka A. G. The synthetic humic acid contained most (approximately 40%) of the compounds of approximate molecular weight of 8000--10 000. In the bacterial and synthetic material the content of the compounds with the molecular weight above 100 000 was very similar (8%--12%).  相似文献   

11.
Liver cell sap from normally fed rats, rats fed with a highly-carbohydrate diet and fasted rats was chromatographed on DEAE-cellulose (pH 7.0). The chromatogram from each diet group was analyzed for pyruvate kinase activity and endogenous substrates of cyclic AMP-stimulated protein kinase. The materials were pooled into five phosphorylatable fractions, in each of which phosphate incorporation at 0.1 mM and 1.0 mM [32P]ATP in the presence of cyclic AMP and protein kinase was determined.For characterization of the phosphorylatable components, thin-layer gel chromatography on Sephadex G-200 and polyacrylamide gel electrophoresis in detergent were used for determination of native and minimal molecular weights, respectively.Except for pyruvate kinase, eight components which incorporated at least 0.05 nmol of [32P]phosphate/g of liver were detected. The phosphorylation of four of them was stimulated by cyclic AMP. Their minimal molecular weights were 42 000, 21 000, 52 000 and 49 000. The component with a minimal molecular weight of 42 000 seemed to have a native molecular weight of 160 000. Both the 21 000 and the 52 000 component had a native molecular weight of about 110 000–120 000. The protein with a minimal molecular weight of 49 000 could not be correlated with certainty to a native molecular weight. The proteins whose phosphorylation was not stimulated by cyclic AMP had minimal molecular weights of 54 000, 39 000, 34 000 and 22 000.  相似文献   

12.
Plasma membranes of splenic and thymic lymphocytes from ACI rats were analyzed for their protein and glycoprotein components by surface radioiodination with 125I and SDS-polyacrylamide gel electrophoresis. The glycoproteins were extracted with lithium diiodosalicylate, characterized and assayed with antisera to thymic antigen. Plasma membranes of both cell types showed more than 25 proteins of which 10--15 were glycoproteins. Both cells showed five major glycoproteins but their apparent molecular weights or intensities differed. Surface radioiodination showed a 120 000 daltons component, common to both cell types, and a 27 000 daltons thymus-specific component as the most exposed surface glycoproteins. Lithium diiodosalicylate extracts of the plasma membranes contained almost all of the glycoprotein components and comprised 5-6 percent of the total membrane protein and 40-50 percent of the total membrane carbohydrate, with sialic acid content in thymus twice that of the spleen cells. About 1 percent of the total plasma membrane protein and 7 percent of the total isolated glycoproteins from thymocytes were reactive with rabbit anti-rat thymocyte antiserum and the immune precipitates showed two components with apparent molecular weights of 72 000 and 27 000.  相似文献   

13.
Canine tracheal pouch secretions were solubilized with 1% sodium dodecyl sulfate and visualized by sodium dodecyl sulfate-agarose-acrylamide gel electrophoresis. Intact mucus, and water-soluble and insoluble fractions of mucus were shown to be composed of high molecular weight glycoproteins (Mr greater than or equal to 3 . 10(6)) and three major classes of proteins of lower molecular weight (Mr approximately 4 . 10(5), 2 . 10(5), and 6 . 10(4)). When the mucus secretions were further treated with a reducing agent, the glycoproteins were dissociated into subunits which appeared on the gel as three discrete bands. Separation of the high molecular weight glycoproteins from the other proteins was achieved by gel filtration on Biogel A-15m in the presence of 1% dodecyl sulfate following reduction and alkylation of mucus. These glycoproteins were further resolved, using DEAE cellulose chromatography in the presence of 6 M urea, into two protein fractions. Both fractions contained approximately 87% carbohydrate, high amounts of serine and threonine but differed significantly in contents of N-acetyl glucosamine and sialic acid; their mobility on gel electrophoresis was also different. Significant contents of cysteine were noted in both fractions. Results of this study indicate that the canine tracheal pouch preparations provide normal tracheal secretions which bear similarity in structure to the tracheobronchial secretions obtained from human patients.  相似文献   

14.
Mutants with defective lipopolysaccharides (LPSs) were isolated from Pseudomonas aeruginosa PACIR (Habs serogroup 3) by selection for resistance to aeruginocin from P. aeruginosa PI6 Carbenicillin-sensitive mutants were isolated from P. aeruginosa PACI but not all had defective LPSs. Rough colonial morphology and resistance to bacteriophage II9X appeared to be independent of LPS composition. The LPSs from five mutants were analysed and compared with that of the parent strain. Separation of partially-degraded polysaccharides from LPS from PACI on Sephadex G75 yielded two different high molecular weight fractions and a phosphorylated low molecular weight fraction (L). The mutant LPSs lacked most or all of the high molecular weight fractions but retained some low molecular weight material. That from PACI and two of the mutants was separated by elution from Biogel P6 into two fractions. One, L2, was the core polysaccharide while the other, LI, contained short antigenic side-chains attached to the core like the semi-rough (SR) LPSs of the Enterobacteriaceae. The two mutants which gave the LI fraction with Habs 3 and PACI antisera as did the parent strain. The other three mutants were unreactive and their LPSs contained core components only. One appeared to have a complete core while the other two lacked rhamnose and rhammose plus glucose respectively. Thus there may be four types of LPS in PACI: one contains unsubstituted core polysaccharide and yields L2 on acid hydrolysis, another has short antigenic side-chains of the SR type and yields the LI fraction, while the two high molecular weight fractions are derived from core polysaccharides with different side-chains.  相似文献   

15.
Artificial antigens were obtained on the basis of the polysaccharide component of P. aeruginosa complexed with an indifferent protein. Immunological study indicated that the specific polysaccharide of P. aeruginosa lipopolysaccharide contained two structures, high molecular and low molecular, having qualitative and quantitative differences in their hydrocarbon composition. Artificial complex antigens possessed serological and immunogenic properties, the low molecular polysaccharide fraction complexed with protein having less pronounced serological and immunogenic activity than polysaccharide and the high molecular fraction complexed with protein. Antificial complex antigens exerted no protective effect in generalized P. aeruginosa infection in rats.  相似文献   

16.
A study has been made of the developmental changes that occur in the RNA and protein moieties of mRNA-protein particles isolated from newborn and adult rat forebrain free polyribosomes. mRNA-protein particles were isolated by oligo(dT)-cellulose chromatography from salt-washed polyribosomes dissociated by puromycin/0.5 M-KCl treatment as two fractions (E1 and E2) by using Tris/HCl/NaCl eluting buffers containing respectively 25 and 50% (v/v) formamide. Isopycnic centrifugation on CsCl gradients showed that the newborn-derived fractions E1 and E2 has buoyant densities of 1.48--1.50 and 1.41--1.43 g/cm3. Adult-derived E1 and E2 fractions had corresponding values of 1.47 and 1.42 g/cm3. The pooled mRNA-protein particles from the E1 and E2 fractions after deproteinization with proteinase K sedimented with a mean size of approx. 18 S on a sucrose gradient containing 85% formamide with little differences between mRNA molecules from newborn and adult. The mean lengths of the poly(A) segments were similar, being about 130 nucleotides long. Distinct changes were found in the protein composition of the mRNA-protein particles. Fractions E1 and E2 from the newborn contained two major proteins of mol.wts. 74 000 and 52 000 with differences in the relative proportions in each fraction. In contrast, adult fractions E1 and E2 contained predominantly the larger protein. However, the adult fraction E2 contained a more heterogeneous population of minor bands of proteins, including that of mol.wt. 52 000. The findings are discussed briefly in relation to other changes in the developing brain.  相似文献   

17.
Selenium and selenoproteins in the rat kidney   总被引:1,自引:0,他引:1  
Kidney tissue contains a high concentration of selenium that is not accounted for by the known selenoprotein glutathione peroxidase (glutathione: hydrogen-peroxide oxidoreductase, EC 1.11.1.9). In order to investigate the nonglutathione peroxidase selenium, rats were isotopically labeled with [75Se]selenite over a 10-day period. After this time half of the 75Se in kidney homogenate was found in the particulate subcellular fractions. The kidney lysosomes contained unusually high levels of 75Se, yet they did not contain correspondingly high levels of glutathione peroxidase activity. Two selenoproteins having molecular weights less than 40 000 were resolved by gel filtration from a kidney supernatant fraction. A third selenoprotein exhibited a molecular weight of 75 000. This protein contained one 75 000 molecular-weight subunit, and its selenium was in the amino acid selenocysteine. The 75 000 molecular-weight protein was chromatographically distinct from glutathione peroxidase. In order to determine if these selenoproteins protect against cadmium toxicity, 109CdCl2 was administered to rats that were isotopically prelabeled with 75Se. At 3, 25 and 72 h after 109Cd administration, no 109Cd was associated with selenium-containing proteins. Two of the nonglutathione peroxidase selenoproteins were apparently unique to the kidney.  相似文献   

18.
Treatment of bovine cervical mucus glycoprotein with cyanogen bromide gives four fractions, with the molecular weights of the three major fractions being 230 000, 130 000, and 35 000. The results indicate that, as for other glycoproteins, there are different regions along the protein core, some of which have a high sugar content and others which contain considerably less carbohydrate; it seems likely that the regions of lower sugar content may be important to intermolecular linkages. The data suggest that the basic unit of the glycoprotein has a molecular weight of 550 000-600 000, with its protein core consisting of approx. 1200 amino acid residues.  相似文献   

19.
黄粉虫幼虫营养成分分析和保健功能的实验研究   总被引:32,自引:1,他引:31  
杨兆芬  吴小楠 《昆虫知识》1999,36(2):97-100,94
对黄粉虫幼虫干粉的营养成分分析显示,其蛋白质和氨基酸含量分别占干重的59.70%和59.59%;不饱和脂肪酸占总脂肪酸含量的77.05%,其中仅亚油酸就占总脂肪酸含量的41.70%。有饰物 含量均低于国家标准。有机硒含量高达34μg/100g。维生素A和E含量分别为337和898μg/100g。实验表明,干粉液无毒性。具有较好的抗疲劳,延缓衰老和降低血清胆固醇的功能,并能提高小鼠外周淋巴细胞转化率  相似文献   

20.
Partially purified water extract was obtained from the initial water extract by ultracentrifugation. Nine protein fractions differing in molecular weight, homogeneity and the content of lipopolysaccharide (LPS) were obtained by stepwise precipitation with ammonium sulfate and subsequent fractionation in columns packed with Sephadex G-100 and DEAE cellulose. Two protein fractions with a molecular weight of 30000 and 40000 daltons were practically free of LPS. These fractions were homogeneous as shown by analytical centrifugation and formed a single precipitation line with P. aeruginosa antiserum; both fractions were found to be antigenically identical. In the enzyme immunoassay these two fractions proved to be least active in comparison with the other protein fractions, but when used for the immunization of rabbits, they induced the formation of specific protective (for mice) antibodies. Both antisera were equally active in the experiments of the passive protection of mice. The isolated LPS-free proteins are supposed to be the proteins of the outer membrane of P. aeruginosa cell wall and have the properties of protective antigens.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号