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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subcellular fractionation of C57BI/6J mouse brains produced a crude synaptosome preparation which contained virtually all of the Thy-1.2 antigenic activity of the isotonic whole brain homogenate. The Thy-1.2 was solubilized from the synaptosomes, following delipidation with acetone, by deoxycholate extraction. A glycoprotein fraction rich in Thy-1.2 was isolated from the bulk of the detergent-soluble material by lectin affinity chromatography. Fractionation of the lectin retentate by gel filtration chromatography produced a single peak of Thy-1.2 activity purified more than 2000-fold over the original homogenate. SDS polyacrylamide gel electrophoresis of this material revealed a single band which corresponded to an apparent molecular weight of 24,000. Amino acid composition data indicated that the protein portion of the molecule is similar to Thy-1.1 from mouse lymphoblastoid cells. Carbohydrate analysis revealed a qualitative similarity between mouse brain Thy-1.2 and Thy-1.1 from rat brain. Structural differences which could account for the Thy-1.1 and Thy-1.2 antigenic distinctions are apparently too subtle to be detected by compositional analysis.
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PMID:Purification and characterization of mouse brain Thy-1.2 differentiation alloantigen. 8 75

Polyacrylamide gel electrophoresis and crossed immuno-affino-electrophoresis with several free lectins have been used to characterize and to compare the molecular heterogeneity of rat, mouse and human alpha1-fetoproteins. Each alpha1-fetoprotein contains a variable number of electrophoretic variants depending on the gel porosity. In SDS electrophoresis, two molecular size populations are present in rat alpha1-fetoprotein (Mr = 74 000 and 72 000) and in mouse alpha1-fetoprotein (Mr = 73 000 and 72 000) but only one is observed in human alpha1-fetoprotein (Mr = 70 000). The crossed immuno-affino-electrophoresis patterns square with affinity chromatography results and reveal a marked and characteristic heterogeneity for the three alpha1-fetoprotein species with Concanavalin A, Ricinus communis and Lens culinaris lectins. No lectin-alpha-fetoprotein interaction is apparent with Ulex, Lotus and wheat germ lectins. Since similar patterns are obtained whether with purified alpha1-fetoprotein or with unfractionated fresh fetal sera, it is likely that this heterogeneity is not a consequence of artefactual molecular modifications arising during the purification procedure.
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PMID:Microheterogeneity of rat, mouse and human alpha1-fetoprotein as revealed by polyacrylamide gel electrophoresis and by crossed immuno-affino-electrophoresis with different lectins. 8 79

Synaptic membranes were isolated from the forebrains of rats of increasing postnatal ages. Developmentally related changes in the structure and concnetration of synaptic membrane glycoproteins were indicated by: (1) a 2--3 fold increase in glycoprotein sialic acid between 5 and 60 days; (2) a similar increase in the number of membrane receptors for the lectins concanavalin A and wheat germ agglutinin; (3) transient increases between 10 and 17 days in the receptors for lentil and castor bean lectins and (4) an age dependent stimulation of castor bean lectin binding by neuraminidase. Labelling of SDS polysacrylamide gels of synaptic membranes with [125I]concanavalin A or wheat germ agglutinin revealed specific, age dependent changes in the lectin binding properties of individual molecular weight classes of glycoproteins. Differences in the glycoproteins composition of synaptic junctional complexes isolated from 10 and 28-day-old brains were also revealed by lectin binding studies. The results indicate that the number and structure of oligosaccharides associated with synaptic membrane glycoproteins are under developmental regulation.
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PMID:Developmental alteration of rat brain synaptic membranes. Reaction of glycoproteins with plant lectins. 21 93

Human and bovine factor VIII, isolated from cryoprecipitates of fresh plasma by gel filtration on Sepharose CL-2B, gave similar elution patterns and showed comparable distribution of oligomers on SDS agarose electrophoretic gels. The carbohydrate content of individual factor VIII bands, measured by reaction with dansyl hydrazine or binding of glucose/mannose specific concanavalin A, was not directly related to the size or von Willebrand activity of factor VIII oligomers. Staining of disulfide-reduced factor VIII subunits, in polyacrylamide gels, with galactose-specific fluorescein-labelled Ricinus communis lectins, showed an increased binding affinity with increasing size and von Willebrand activity of the parent factor VIII. The von Willebrand activity was strongly inhibited by reaction with Ricinus RCAI lectin, whereas concanavalin A inhibited platelet aggregation only at concentrations above 1 mg/ml. These results suggest that galactose residues are involved in the aggregation of platelets by factor VIII.
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PMID:[Is there a correlation between sugar content, thrombocyte aggregating activity and molecular size of factor VIII?]. 31 62

Glycoproteins from the surface of human T. B and leukemic lymphocytes were isolated and partially characterized by using three different lectins, Lens culinaris lectin (Lc), wheat germ agglutinin (WGA) and phytohemagglutinin from Phaseolus vulgaris (PHA). Cells were labelled either with I125 or 3H-fucose and lysed with detergent. Labelled components were isolated by incubation with lectins and anti-lectin antisera and immune precipitates were analysed by SDS-polyacrylamide gel electrophoresis. The results obtained show: 1) components with a molecular weight of 35,000-27,000 daltons were detected by the three lectins in both B and CLL lymphocytes but not in T lymphocytes; these components have a molecular weight similar to the Ia like antigen; 2) B and CLL lymphocytes were found to share several components of similar molecular size and specially the 35,000-27,000 daltons receptors; 3) in T lymphocytes, the 35,000-27,000 daltons components were absent, but components of low molecular weight, about 23,000, were easily detected. These data indicate that lectins bind to several identical receptors on the surface of different lymphocytes populations but also to some specific components.
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PMID:Surface glycoproteins from human T, B and chronic lymphatic leukemia lymphocytes isolated by 3 different lectins. 31 13

Mannose-binding hemagglutinins were found in the extracts of a pyocyanin-forming Pseudomonas aeruginosa, which contain galactose-specific hemagglutinins. They were purified simultaneously with the latter proteins by heating to 70 degrees C, precipitating with ammonium sulfate, application to a Sepharose 4B column, and elution from it by 0.05 M mannose. The mannose-specific hemagglutinins were shown to be similar to the galactophilic ones in (a) being glycoproteins of very low molecular weight (about 11 000 by SDS gel electrophoresis), (b) their tendency to aggregate, and (c) their ability to effect stronger agglutination of erythrocytes treated with papain than of untreated ones. They were found to resemble them also in their reaction with simple sugars and interactions with divalent cations, which are essential for their activity. In these properties, as well as in their relative resistance to heat and to proteolytic enzymes, these two types of bacterial hemagglutinins are like most of the plant, contrasted with the animal, hemagglutinins. The reactions with mannose and mannose-bearing compounds (yeast mannan, horseradish peroxidase (EC 1.11.1.7), and serum globulins), which are not shared with the galactophilic Pseudomonas hemagglutinins, indicate a relationship of the mannose-binding protein of Pseudomonas to the plant lectin concanavalin A. The mannose-binding hemagglutinins do not exhibit identical cell-agglutinating spectra owing to difference in profiles of sugar specificity and relative affinity to mannose derivatives compared with free mannose.
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PMID:Mannose-binding hemagglutinins in extracts of Pseudomonas aeruginosa. 40 63

Surface proteins and glycoproteins of RBL cells were labelled enzymatically with 125I and then solubilized with Nonidet P-40. Analysis by polyacrylamide-gel electrophoresis in SDS on 10% gel revealed 10 distinctive peaks ranging in molecular weights from 17,000 to 200,000 daltons. Mainly components of higher molecular weights were bound by lentil-lectin Sepharose and could be eluted with alpha-methyl mannoside. The receptor for IgE was clearly shown to bind to the lentil-lectin. A second cell surface component which previously had been shown to bind to IgE-Sepharose as well, was found to bind only slightly to lentil-lectin. Thus, it can be concluded that the receptor for IgE is a glycoprotein with mannose and/or N-acetylglucosamine in the carbohydrate moiety(s).
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PMID:Lentil-lectin affinity chromatography of surface glycoproteins and the receptor for IgE from rat basophilic leukemia cells. 42 83

Synaptic junction (SJ) were isolated by subcellular fractionation from different areas of the steer brain and from the brains of different species (steer, rat, chicken and human) for the purpose of comparing their protein and glycoprotein composition. The synaptic junction fractions from different brain regions and species were of comparable morphological purity. Analysis of the polypeptide composition of isolated synaptic junction fractions via SDS polyacrylamide gel electrophoresis showed that the major polypeptides were represented in all junctional fractions independent of their source. Tubulin, actin, the major 52,000 Mr postsynaptic density protein and a group of proteins with a molecular weight of 200-250,000 Mr were all similarly represented. Most other components were also similar but quantitative differences were found for a few polypeptides. Interspecies differences were more prevalent than those between different brain areas of the same species. The protein compositions of different brain areas were similar even when an area consisting of primarily one neuronal type was compared to areas containing a mixture of neuronal types. However, two-dimensional gel electrophoresis revealed distinct (but usually minor) polypeptides in enriched quantities in one or more brain areas. Tryptic peptide maps were carried out on the major postsynaptic density protein of different species. These maps showed a high degree of conservation in this protein's primary structure among all species studied. The glycoproteins of isolated synaptic junctions which bind the plant lectin concanavalin A (Con A) were also examined. To identify individual Con A binding components, SJ fractions were solubilized and constituent glycoproteins were separated by SDS gel electrophoresis. Gels were then incubated in 125I-Con A. The glycoproteins which bound Con A in gels were few in number and were not the major Coomassie blue staining bands. The great majority of the Con A binding glycoproteins were similar between species and among brain areas of the same species.
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PMID:Protein and glycoprotein composition of synaptic junctions prepared from discrete synaptic regions and different species. 45 75

Experiments with biosynthetic incorporation of 3H-amino acids into murine and guinea pig Ia antigens have indicated that these antigens consist of two polypeptide chains of 33,000 and 25,000 daltons, respectively, occasionally linked by disulfide bonds into a 58,000 dalton molecule. In contrast, studies with lactoperoxidase-catalyzed radioiodination have indicated that these Ia antigens consist of only a single chain of 25,000 daltons. We therefore undertook a study to explore the basis of these discrepant results. Since 3H-tyrosine labeled both chains well, the lack of tyrosine residues in the 33,000 dalton chain could not be the explanation for the lack of radioiodination. However, by partially purifying the Ia antigen preparation with Lens culinaris (lentil) lectin affinity chromatography before immunoprecipitation and by increasing the resolution of analysis by using discontinuous-SDS polyacrylamide gel electrophoresis, it was possible to show that the 33,000 dalton chain was in fact radioiodinated, though still poorly so relative to the 25,000 dalton chain, and that a radioiodinated 58,000 dalton molecule could be detected. These experiments suggest that the 25,000 dalton chain is more exposed to the external cellular environment, and thus more readily iodinated by lactoperoxidase. In addition, the studies indicate that the choice of labeling method, purification procedures, and analytical methods must be taken into account when interpreting experimental results.
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PMID:Labeling characteristics and separation of Ia antigen subunits. 62 2

A mitogenic lectin has been isolated from saline extract of Lathyrus odoratus seeds by (NH4)2SO4 precipitation and subsequent chromatography on DEAE-Sepharose and CM-Sepharose. The isolated lectin was almost homogeneous by SDS gel electrophoresis and gel filtration, but multiple bands were obtained on isoelectric focusing. The molecular weight, determined by gel filtration, was 37,000. Gel electrophoresis in the presence of SDS gave a molecular weight of 19,000, thus suggesting that the lectin is a dimer. It agglutinated human erythrocytes of the different ABO groups equally well. Human lymphocytes were exposed to the lectin or PHA, and the incorporation of thymidine was measured. Compared with PHA, which stimulated maximally in the concentration range of 0.25--1microgram/ml, the L. odoratus lectin had optimal activity at concentrations of 35 microgram/ml and higher.
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PMID:Isolation and partial characterization of a mitogenic lectin from Lathyrus odoratus seeds. 71 28


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