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

A rapid method for isolation of a major surface membrane glycoprotein from whole, unfractionated cultured human B lymphoblasts is described. After detergent solubilization the method uses gel filtration followed by affinity chromatography on Sepharose Con A and then alkaline acrylamide gel electrophoresis. Specific high-titre, rabbit antisera to the isolated protein reacted with cultured and normal peripheral blood B lymphocytes, as well as peritoneal macrophages from a renal dialysis patient. The antisera selectively inhibited the mixed lymphocyte reaction at high dilution. The protein reacted with a heterologous antiserum to HL-B antigens and contained subunits of MW 33 000 and 27 000. Resolution of the subunits, however, required a discontinuous SDS gel system. These properties indicate its similarity to murine Ia antigens. The protein was not associated with beta 2 microglobulin and showed no structural or antigenic similarity to the major erythocyte glycoprotein, glycophorin. Antisera to the protein failed to precipitate surface-radiodinated components from similarily treated extracts of cultured human T lymphoblasts. This method now makes available a reference membrane glycoprotein from a differentiated, nucleated human cell in sufficient purity and quantity for kinetic and biosynthetic studies.
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PMID:Isolation of a human B lymphocyte membrane protein with Ia-like properties. 10 38

Pulse-chase experiments after synchronous initiation of translation indicate that the larger Venzuelan equine encephalomyelitis (VEE) virus membrane glycoprotein E2, is derived by proteolytic cleavage of the precursor, PE2. The structural proteins of VEE virus strains representing each of the antigenic subtypes and varieties have been compared by discontinuous SDS-polyacrylamide gel electrophoresis. Nucleocapsid proteins of all isolates were similar in size (mol. wt. 35 to 36 X 10(3). The mol. wt. of E1 varied from 48 to 51 X 10(3) and the mol. wt. of E2 glycoproteins ranged from 53 to 59 X 10(3). Pixuna virus contained a third envelope glycoprotein of 59 X 10(3) mol. wt. in addition to the two major glycoproteins of mol. wt. 53 X 10(3) and 48 X 10(3) respectively. The isoelectric points (pI) of E1 and E2 for all VEE strains studied were approx. 7 and 9 respectively. Both glycoproteins of TC-83 virus induced precipitating antibodies which reacted only with the homologous purified E1 and E2 glycoproteins. Antibodies to E2 protein of each virus neutralized virus infectivity and inhibited the agglutination of goose erythrocytes by virions. Haemagglutination-inhibition tests using antisera to E2 glycoproteins of prototype viruses, representing each of the antigenic subtypes and varieties, differentiated the viruses into subtypes I, II, III and IV with subtype I divided into variants 1AB, 1C, 1D and 1E.
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PMID:Biochemical and antigenic comparison of the envelope glycoproteins of Venezuelan equine encephalomyelitis virus strains. 11 35

We have studied the induction of cytotoxic activity in human peripheral blood lymphocytes by heated allogeneic cells. By separating T and B cells from the responder and stimulator cell populations we found that cytotoxic cells are generated in responder T cell populations by both T and the B stimulator cells. Rabbit antisera to a membrane glycoprotein complex (33,000 and 27,000 m.w. by SDS-gel electrophoresis) isolated from a human B cell line were utilized to explore further the nature of the effector cells in this type of cytotoxicity. This antiserum, present during the 6-day-culture period, blocked generation of cytotoxic effector cells. Depletion of cells bearing the B cell antigen from the responder cell population by anti-B cell serum and complement (C) eliminated cytotoxicity. Furthermore, heated cell-induced cytotoxicity was blocked by simply pretreating the responder or the stimulator cell populations with anti-B cell serum in the absence of C. Apparently the human lymphocyte that functions as the effector cell in heated cell-induced cytotoxicity bears the Ia-like antigen that might be important in triggering this type of cytotoxicity.
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PMID:Cell types involved in cytotoxicity induced by heated cells and inhibition of this cytotoxicity by anti-human B cell sera. 14 16

1. The membrane glycoprotein composition of the blood platelets of 13 mammalian species has been compared by SDS-polyacrylamide gel electrophoresis. 2. A basic pattern of 2-3 predominant high molecular weight glycoprotein bands was observed, however species differences in their relative rates of migration and abundance were apparent. 3. Wide species differences in the number and rate of migration of the acidic glycopeptides released by trypsin digestion of washed platelet suspensions were observed following polyacrylamide gel electrophoresis in the absence of SDS.
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PMID:Comparative studies on the glycoprotein composition of mammalian platelets. 31 52

The crude red cell glycoproteins obtained by four different methods are compared. The most selective isolation of the major membrane glycoprotein (MN blood group glycoprotein) is achieved by the phenol-water extraction procedure. A different degree of aggregation of this glycoprotein in water and in various buffers is demonstrated. The gel filtration of the crude glycoprotein on a Sepharose 4B column in 0.05 M pyridine--acetate buffer of pH 5.3 gives four fractions with different chemical compostition and serologic properties. The fractions obtained are heterogenous in SDS-PAGE and represent different kinds of glycoprotein aggregates. The distribution of serologic activities in the fractions obtained indicates that A, B and I activities found in the crude prepration of red cell glycoprotein are not connected with MN glycoprotein.
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PMID:Heterogeneity of aggregates of the human erythrocyte membrane glycoproteins. 44 38

Human platelet plasma membrane glycoprotein I with an apparent molecular weight of approximately 150,000 has been shown to be one of the proteins retained by thrombin immobilized on Sepharose 4B. The retained glycoprotein has been recovered by sodium dodecyl sulfate elution and characterized by SDS polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol.
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PMID:Affinity chromatographic demonstration of a thrombin binding protein from the platelet plasma membrane. 69 35

Rabbit and thrombastheinic platelet membranes were examined by SDS polyacrylamide gel electrophoresis. Both rabbit and thrombasthenic platelets failed to spread on siliconized glass surfaces and revealed platelet membrane glycoprotein patterns quite different from those of normal human platelet membranes. Typical for normal platelet membranes are four high molecular weight glycoprotein bands. The platelet membranes from rabbits and from one thrombasthenic patient showed only the first major glycopolypeptide with an apparent molecular weight of 135000 and 120000 D respectively. Other platelet membrane glycopeptides (both the carbohydrate and polypeptide moiety) were completely absent in thrombasthenia. The rabbit platelet membrane yet contains two strong polypeptides in this high molecular weight region, however, without corresponding carbohydrate moieties. Therefore, we support the view that the carbohydrate chains from two high molecular weight glycoproteins are of importance for platelet spreading on glass surfaces.
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PMID:[Failure of platelet spreading in thrombasthenia due to changes of high molecular weight membrane glycopeptides (author's transl)]. 94 Feb 97

We have previously shown that tomato lectin binds specifically to the 60-90 kDa membrane glycoprotein of parietal cell tubulovesicles, the beta-subunit of the gastric H+/K(+)-ATPase (proton pump) [Callaghan, Toh, Pettitt, Humphris & Gleeson (1990) J. Cell Sci. 95, 563-576; Toh, Gleeson, Simpson, Mortiz, Callaghan, Goldkorn, Jones, Martinelli, Mu, Humphris, Pettitt, Mori, Masuda, Sobieszczuk, Weinstock, Mantamadiotis & Baldwin (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 6418-6422]. Here we have exploited this interaction for the development of a rapid single-step chromatography procedure for the purification of an active pig gastric proton pump complex. Initially, H+/K(+)-ATPase-enriched membranes, prepared from pig gastric microsomes by density-gradient centrifugation, were extracted in 1% Triton X-100 and passed through a 1 ml tomato lectin-Sepharose 4B column. The bound material, eluted with 20 mM-chitotriose, showed a major band with an apparent molecular mass of 95 kDa, and a faint broad band of 60-90 kDa, by SDS/PAGE. N-Glycanase treatment of the bound material resulted in the appearance of a 35 kDa band, the size of the protein core of the 60-90 kDa glycoprotein beta-subunit. The two components were identified as the 95 kDa alpha-subunit and the 60-90 kDa beta-subunit of the gastric H+/K(+)-ATPase, by immunoreactivity with monospecific antibodies, and by tryptic peptide sequences of the tomato-lectin-bound material. The beta-subunit was present in approximately equimolar amounts to the catalytic alpha-subunit. Whereas the gastric H+/K(+)-ATPase was not active after solubilization in 1% Triton X-100, solubilization of density-gradient-purified membranes in the non-ionic detergent, C12E8, followed by chromatography of the extract on tomato lectin-Sepharose 4B, resulted in the purification of the gastric H+/K(+)-ATPase complex which exhibited K(+)-dependent phosphatase activity. This is the first report of a rapid purification of a partially active solubilized gastric H+/K(+)-ATPase complex.
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PMID:Rapid purification of the gastric H+/K(+)-ATPase complex by tomato-lectin affinity chromatography. 131 70

An alpha-D-galactoside-specific lectin from Bandeiraea simplicifolia (BSLI) showed differential binding to cortical cells of the wool follicle bulb. The lectin bound to cells on one side only of the bulb and was completely blocked by alpha-D-galactose. The region of lectin binding extended from presumptive cortical cells at the base of the bulb to cortical cells at the top of the bulb, disappearing as cortical cells entered the fibre cortex. An orthocortex-specific monoclonal antibody was used to show that cortical cells recognised by the lectin lie directly below the fibre orthocortex and presumably give rise to the orthocortex. The results suggest that two distinct populations of presumptive cortical cells are present only two to three cell layers from the base of the bulb in a region where no morphological differences are detectable. The lectin-bound pre-cortical cells appear to give rise to orthocortical cells while cells not bound by lectin presumably give rise to paracortical cells. Electron microscopy showed that the lectin bound to sites on the plasma membrane, probably on the extracellular surface. This suggests that the lectin target may be a membrane glycoprotein or glycolipid. Two polypeptides recognised by BSLI were separated from wool follicle extracts by SDS-gel electrophoresis. These polypeptides migrated at approximately 69 kDa and 17 kDa. However, only the 69 kDa molecule showed the expected loss of binding by BSLI in the presence of alpha-D-galactose. Further work will be required to determine if this glycoprotein is the bulb cell molecule recognised by BSLI.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential lectin binding to presumptive cortical cells of the wool follicle bulb. 140 Jun 37

Intravesical bacillus Calmette-Guerin (BCG) has been shown to be an effective treatment for superficial transitional cell carcinoma of the bladder (TCC). The mechanisms by which BCG limits tumor cell activity have thus far been unclear. We investigated the interaction between BCG and invasive human TCC cell line EJ in an in vitro invasion assay. We observed that BCG inhibited the invasion of EJ cells through an artificial basement membrane. In terms of the steps involved in tumor cell invasion, i.e. attachment, proteolysis, and motility, BCG was found to limit tumor cell motility. Attachment and proliferation of tumor cells were not affected by BCG. The effects of BCG on tumor cell migration were mediated by fibronectin (FN), a basement membrane glycoprotein component. Abrogation of BCG-FN-tumor cell interactions with anti-FN antibodies eliminated the ability of BCG to block tumor cell invasion. Fibronectin appears to link BCG and tumor cells via independent FN binding receptors to separate domains of the FN molecule. The molecular mechanism by which BCG may limit tumor cell motility may be its ability to protect against the formation of specific FN sequences as a result of protease cathepsin B digestion. A 31 kD and 27 kD FN band were absent from purified or tumor cell associated cathepsin B digestion when incubated in the presence of BCG, but present in the absence of BCG. Furthermore when purified from SDS polyacrylamide gel electrophoresis, the fragments were shown to have motility stimulating activity for the invasive EJ cells. These findings suggest that BCG functions as a potent inhibitor of tumor cell invasion. We conclude that BCG-fibronectin-tumor cell interactions may have a direct influence on the invasive mechanisms, such as motility, of tumor cells.
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PMID:Bacillus Calmette-Guerin abrogates in vitro invasion and motility of human bladder tumor cells via fibronectin interaction. 151 57


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