Klebsiella pneumoniae secreted protein-containing antigens in the system of adaptive immunity

The study was aimed at the evaluation of the antigenic properties of K. pneumoniae secreted protein-containing antigens with a molecular weightt of 21 and 34-35 kD, obtained from supernatant culture fluid. As confirmed by the method of flow cytofluorimetry, the protein-containing fractions belonged to the secreted components of the microbial cell. The fraction with a molecular weight of 34-35 kD possessed high antigenic activity and contributed to the formation of specific antibodies after the immunization of mice. At the same time none of the protein fractions lead to an increase in the level of autoantibodies in mouse blood sera to organ-unspecific and organ-specific antigens. As revealed by the method of solid-phase, in 6 (27.3%) from 22 patients of patients with rhizomelic spondylitis had an increased level of IgG to K. pneumoniae cell-wall antigens with a molecular weight of 34-35 kD. An increase in the level of IgG to the secreted protein-containing fraction with a molecular weight of 34-35 kD was detected only in one patient (4.5%) (p<0.05).     

The antigenic and allergenic properties of an extract from the house dust mite Dermatophagoides farinae]

To evaluate the antigenic composition and allergenic activity of D. farinae extracts, the methods of rocket and cross immunoelectrophoresis, gel chromatography and the inhibition of the radioallergosorbent test have been used. The presence of 9-20 antigenic components has been established. The fractions of the extract with a molecular weight of 10-200 kD possessed the highest capacity of inhibiting the binding of specific IgE antibodies from the pool of sera from patients sensitized to D. farinae.     

Isolation of focal contact membrane using saponin

The fragments of lower cell surface remained attached to the substrate after incubation of mouse or chick fibroblasts in 0.2% saponin solution and subsequent removal of cells under the action of shearing force. These fragments corresponded exactly to the cellular focal contacts seen by interference reflection microscopy. Ultrastructurally they were membrane fragments with typical three-layered structure. No cytoskeletal components were found in saponin-isolated focal contact membranes either by immunofluorescence or electron microscopy. Only one major cell-derived protein with an apparent molecular weight (MW) of 51 kD (chick embryo fibroblasts) or 47 kD (mouse embryo fibroblasts) remained on the substrate after saponin treatment and removal of cells.     

白鲢鱼与黄鳝血清转铁蛋白的分离纯化及其结构和性质的比较

1.白鲢鱼与黄鳝血清转铁蛋白在分离纯化上的差异。2.用SDS-PAGE测定分子量,白鲢鱼血清转铁蛋白有两个组份,分子量分别为77kD和70kD;黄鳝血清转铁蛋白为单一组份,分子量为68.1 kD。3.白鲢鱼与黄鳝血清转铁蛋白都含糖,但都不与ConA-Sepharose柱结合。4.白鲢鱼与黄鳝血清转铁蛋白氨基酸组成的测定和比较。5.白鲢鱼与黄鳝血清转铁蛋白用胰蛋白酶在相同条件下进行酶解,白鲢鱼能得到分子量在37kD左右的二个片段,而黄鳝则几乎不能被胰蛋白酶酶解。6.白鲢鱼血清转铁蛋白在404.5nm处有一特异吸收峰,而黄鳝则在407.5nm处。     

Immunochemical characterization of a human high molecular weight — melanoma associated antigen identified with monoclonal antibodies

Sodium dodecyl sulfate polyacrylamide gel analysis of a high molecular weight (HMW) human melanoma associated antigen (MAA) defined by murine monoclonal antibodies revealed a number of distinct polypeptides ranging from 80,000 up to 280,000 daltons, in addition to an extremely heterogeneous group of components distributed over a wide range in apparent molecular weight (300,000-700,000 daltons). The 280,000 dalton and the larger heterogeneous molecular weight material are glycosylated since they are labeled with 3H-sugars. The HMW-MAA is readily solubilized in the absence of detergents and the entire series of polypeptides fractionates together in the void volume of a Sephadex G200 column. Peptide maps of the various polypeptides of the HMW-MAA, generated by Staphylococcus aureus V-8 protease, are essentially the same except that some of the proteolytic fragments derived from the lower molecular weight polypeptides (80,000 daltons) are present in greater amounts than are similar fragments derived from the larger molecular weight polypeptides; the latter finding suggests that the complexity in molecular weight of the MAA may reflect combinations of several base subunits. Proteolytic cleavage of the HMW-MAA generates a number of peptides ranging in molecular weight from 77,000 daltons to less than 12,000 daltons, which still react with monoclonal antibodies and can distinguish monoclonal antibodies specific for different antigenic determinants of this MAA.     

Purification and characteristics of a protective factor from Bacillus anthracis toxin

It was found that during filtration of a sterile toxic cultural supernatant (TCS) obtained by 24 hour cultivation of the vaccinal strain through a column packed with porous glass or silochrome not only oedematic (OF) and lethal (LF), but also protective (PF) factors of toxin are adsorbed on the column. Elution of adsorbed antigens allowed for rapid concentration and purification of biologically active components of toxin from large volumes of TCS under conditions of limited proteolysis. The experimental results suggest that in 24 hour TCS and PF exists as large (87 kD) molecules as well as low molecular weight fragments whose molecular mass is of the order of 17-18 kD. The PF preparations whose molecular mass is below 68 kD possess a weak biological activity.     

Identification of allergens in Indian fishes: hilsa and pomfret exemplified by ELISA and immunoblotting

Enzymed-linked immunosorbent assay of hilsa and pomfret muscle extracts showed specific IgE binding to ten allergic patients' sera, the results corroborated to that of skin prick test. Comparison of allergen profiles of the two fish extracts by immunoblotting revealed a common antigenic protein of 50 kDa and some high molecular weight fish allergens instead of low molecular weight parvalbumin found in several fishes. Purified and well characterized fish allergens are always considered better than crude fish extracts for diagnostic use.     

汉滩病毒核蛋白的分段表达及抗原表位分析

在大肠杆菌中对汉滩病毒Ｓ基因４种不同长度片段的重组表达质粒进行诱导表达。结果表明表达的４种ＧＳＴ－ＮＰ融合蛋白均以不溶性包含体形式存在于茵体细胞内,表达量分别占菌体蛋白总量的２９－３６％,分子量分别约为７２ｋＤ、６６ｋＤ、５４ｋＤ和４４ｋＤＤ。Ｗｅｓｔｅｒｎ ｂｌｏｔ显示５４ｋＤ和７２ｋＤ融合蛋白用酶标记汉滩病毒ＮＰＭｃＡｂｌＡ８和抗ＧＳＴ ＭｃＡｂ ３Ｃ１１染色呈阳反应。６６ｋＤ和４４ｋＤ融合蛋     

Monoclonal Antibodies Specific for Members of the Genus Endotrypanum

Twenty-six monoclonal antibodies were produced against membrane-enriched preparations of Endotrypanum schaudinni or Endotrypanum sp. promastigotes. Fifteen of these monoclonal antibodies (E1-E15) reacted only with the standard strain of E. schaudinni , M6159. Monoclonal antibodies E16-E26 were considered Endotrypanum specific; no cross reactivity was detected with any other genus of the family Trypanosomatidae (Leishmania, Trypanosoma, Leptomonas. Herpetomonas or Crithidia) by dot-blot radioimmune assay. By indirect immunofluorescence assay, the antigens recognized by Endotrypanum specific monoclonal antibodies appear to be associated with the surface of the parasite. Based on Western blot analysis, 4 antigenic molecules ranging in molecular weight from 24 kD to 160 kD were identified by monoclonal antibodies specific for the strain of E. schaudinni , M6159. Monoclonal antibodies specific for the genus Endotrypanum identified an antigen of molecular weight 48 kD as well as a diffuse component migrating with an apparent molecular weight of 64–200 kD.     

Monoclonal antibodies specific for members of the genus Endotrypanum

Twenty-six monoclonal antibodies were produced against membrane-enriched preparations of Endotrypanum schaudinni or Endotrypanum sp. promastigotes. Fifteen of these monoclonal antibodies (E1-E15) reacted only with the standard strain of E. schaudinni, M6159. Monoclonal antibodies E16-E26 were considered Endotrypanum specific; no cross reactivity was detected with any other genus of the family Trypanosomatidae (Leishmania, Trypanosoma, Leptomonas, Herpetomonas or Crithidia) by dot-blot radioimmune assay. By indirect immunofluorescence assay, the antigens recognized by Endotrypanum specific monoclonal antibodies appear to be associated with the surface of the parasite. Based on Western blot analysis, 4 antigenic molecules ranging in molecular weight from 24 kD to 160 kD were identified by monoclonal antibodies specific for the strain of E. schaudinni, M6159. Monoclonal antibodies specific for the genus Endotrypanum identified an antigen of molecular weight 48 kD as well as a diffuse component migrating with an apparent molecular weight of 64-200 kD.     

Study of structural heterogeneity of polymerized hemoglobin using biochemical and immunochemical methods

The structural heterogeneity of crosslinked pyridoxalated hemoglobin (polyHb-PLP) have been investigated by the methods of gel-filtration, isoelectric focusing and immunoelectrophoresis. It was established that the heterogeneity of poly-Hb-PLP is mainly depicted by polydispersion of molecular weight and less by the changes in the isoelectric properties. The qualitative difference has been shown between the immunochemical properties of the native hemoglobin and poly-Hb-PLP, which gives the suggestion of the formation of new antigenic determinants as a result of chemical modification and of more expressed antigenicity of modified hemoglobin compared with native protein. Poly-Hb-PLP has wide antigenic spectrum that corresponds to its structural heterogeneity. The data obtained suggest that the decrease in the antigenic activity of poly-Hb-PLP can be achieved by the lowering of the part of high molecular weight components.     

Allergenic activity of some kinds of plant pollen

Allergenic active fractions of ragweed, wormwood, goosefoot and sunflower pollen with a molecular weight of 37 000, 19 000, 35 000 and 14 000, respectively, were isolated by chromatography on Sephadex. All studied allergens had similar properties: affinity to Sephadex which was more pronounced to Sephadex G-75 than to G-100; absorbing components had no activity; allergenic and antigenic activities were determined only in fractions eluted in the bed volume of the column. Affinity of the allergans to Sephadex did not depend on the eluent type, but decreased in potentiation of the buffer ionic strength.     

In maize,glutelin-2 and low molecular weight zeins are synthesized by membrane-bound polyribosomes and translocated into microsomal membranes

Summary Experiments to establish the site of biosynthesis and the possible translocation into microsomes of glutelins-2 (28 kD G2) and low molecular weight zeins (10, 14, 15 kD Z2) have been carried out. Free and membrane-bound polyribosomes as well as microsomal membranes were isolated from immature endosperms of W64A Zea mays L. In vitro translation studies were carried out in the presence and in the absence of membranes using [³⁵S]-methionine or [³⁵S]-cysteine as precursors. Cell-free translation products were characterized by electrophoretic mobility, solubility and antigenic properties. The results obtained indicate that 28 kD G2 and low molecular weight zeins are primarily synthesized on membrane-bound polysomes. From experiments using proteinase K as a probe, we also conclude that these proteins are translocated into microsomes where they accumulate. The translocated and pre-28 kD G2 proteins do not present changes in the apparent molecular weight. However we show that there are differences in their isoelectric points, a fact that indicates the existence of 28 kD G2 processing.     

四膜虫中存在角蛋白样成分(简报)

中等纤维是脊椎动物细胞中普遍存在的一种细胞骨架成分,在一些无脊椎动物细胞中也发现有这类成分存在。据报道,枪乌贼的巨     

Experimental evaluation of recombinant polypeptides as Streptococcus Group B vaccine

Recombinant polypeptides corresponding to the conservative N-terminal area of Bac surface protein of group B streptococci (GBS) and having the human IgA binding-site were obtained and evaluated in terms of Immunogenic and protective properties. GBS strain 219, serotype 1 bc, served as the source of chromosomal DNA used for cloning. Three polypeptides P1, P5 and P6 were constructed. Polypeptides P1 and P5 with a molecular weight of 22 kD were coded by practically identical DNA fragments (685 nucleotide pairs) and differed in two aminoacids In their central part. Polypeptide P6 had a molecular weight of 35 kD, The fragment of recombinant Bac protein with a molecular weight of 35 kD was found to have protective properties: when used for the subcutaneous immunization of animals, it stimulated the development of immune response capable, in case of challenge, to induce accelerated elimination of streptococci and the prevention of the mice death. Recombinant fragment P6 of GBS protein Bac may be regarded as a candidate for inclusion into GBS-specific vaccine.     

Expression of differentiation and age-related antigens on chicken erythroleukemia cells transformed by avian erythroblastosis virus (AEV)

Immature circulating chicken red cells express on their surface two antigenic molecules referred to as Im 48 kD and Im 140 kD antigens. The Im 140 kD antigen is not present beyond the erythroblast stage while the expression of Im 48 kD antigenic molecule remains detectable on circulating erythrocytes of embryos and young chickens, but not on erythrocytes of adult animals. In addition to Im 48 kD and Im 140 kD antigens, the avian erythroblastosis virus (AEV)-transformed erythroid cells express two novel high molecular weight (MW) immature antigens referred to as Im 150 kD and Im 160 kD. Since the transformed erythroid cells are apparently blocked at a stage close to the colony-forming units erythrocytic (CFU-E), these molecules might be expressed on these progenitor cells. The age-related antigenic molecules referred to as E1 48 kD and A 40 kD/A 85 kD antigens are detected on erythrocytes of embryos (and young chickens) and adult animals respectively. The E1 48 kD antigen as well as an antigen related to the A 40 kD were also detected on AEV-transformed erythroid cells deriving from both young chicken bone marrow and yolk sac. The presence of an adult antigen on the embryonic cells might well be related to the transformation by AEV, since the yolk sac CFU-E progenitor cells do not bear the adult antigenicity.     

20-Hydroxyecdysone induced aggregation of Drosophila S3 cells is inhibited by antibodies to a hormone-dependent extracellular glycoprotein

Summary The S3 cell line of Drosophila exhibits numerous responses to the molting hormone 20-hydroxyecdysone, including mitotic arrest, cell aggregation and extensive changes in cell surface and extracellular glycoproteins. We have produced polyclonal antibodies to a major hormone induced extracellular glycoprotein to investigate the role of this molecule in cell aggregation. This glycoprotein with a molecular weight of 110 kD (P110) is found primarily in the culture medium of hormone-induced cells. Upon reduction, the electrophoretic mobility of P110 is decreased, indicating the presence of internal disulfide bonds. Results from treatment of medium proteins with a cross-linking reagent indicate that the molecule is part of a higher molecular weight oligomer (300–400 kD). Fab fragments of anti P110 effectively inhibit the reaggregation of hormone-treated S3 cells, while preimmune Fab fragments have no effect. On the basis of these results, we propose that the P110 glycoprotein complex in the medium of hormone-treated cells functions in hormone-dependent cell-cell adhesion.     

Fetuin: a serum component associated with rat Sertoli and spermatogenic cells in coculture

Cocultures of rat Sertoli-spermatogenic cells plated in a culture medium supplemented with 10% fetal bovine serum for 6-12 h and then maintained in serum free, hormone/growth factor-supplemented medium accumulated an acidic glycoprotein of molecular weight of 68,000 dalton (68 kD) and isoelectric point range of about 4.2-3.5. Anion exchange chromatography has allowed the partial purification of this protein, which consists of a major protein band of 68 kD and two minor, low molecular weight components. A rabbit antiserum raised against the 68 kD component also crossreacts with the two low molecular weight components, thus suggesting that these two minor components are antigenically related to the 68 kD protein. The 68 kD protein has been identified as fetuin, the major component of fetal bovine serum, based on similar molecular weight, isoelectric point, immunoreactivity and trypsin inhibitory activity. Labeling experiments with [14C]amino acid mixture show that 68 kD protein is not synthesized by cocultured rat Sertoli and spermatogenic cells. Immunocytochemistry and Western blot approaches carried out under various experimental conditions support the view that the fetuin-68 kD protein is taken up from serum by both Sertoli cells and pachytene spermatocytes. Because fetuin 1) behaves as a carrier protein for growth factors, 2) has protease inhibitory activity, 3) is preferentially internalized by Sertoli cells and pachytene spermatocytes and 4) fetal bovine serum-supplemented medium impairs spermatogenic cell viability, there is a need to further define appropriate conditions for optimizing long-term viability and differentiation of spermatogenic cells in vitro.     

Independent folding of autolytic fragments of thermolysin and their domain-like properties

High molecular weight autolysis products from thermolysin have been isolated and identified. The primary fragments correspond to residues 1 to 187-204 (21kD) and residues 187-204 to 316 (12kD), respectively. The fragments are both capable of independent refolding upon removal of denaturant. On the basis of these results, we suggest that the first step in the unfolding pathway of thermolysin involves unfolding of an interdomain region and domain separation. Bound calcium ions at sites 1, 2 and 4 play a major role in protecting the protein against both autolysis and unfolding, probably by stabilizing the interdomain region and enhancing domain-domain interactions.     

Amyloid kidney stones of uremic patients consist of beta 2-microglobulin fragments

Urinary stones with amyloid structure, obtained from uremic patients, were analyzed according to molecular weight, amino acid sequence, and antigenic content. A major protein of approximately 7 kD, designated AB protein, was isolated by size exclusion using HPLC in 60% formic acid. AB protein reacted in immunodiffusion only with an antiserum to beta 2-microglobulin, with beta 2m spurring over AB protein. N-terminal amino acid sequence analysis defined two fragments homologous to beta 2m. One fragment commenced with Ile at position 7 and the other with Ser at position 20, with a cleavage point subsequent to a lysyl residue in both. It is concluded that beta 2m is a precursor of urinary amyloid stones and intratubular concretions of patients with preterminal and terminal renal failure; limited proteolysis is involved in AB amyloid generation.