Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At pH 5 influenza virus hemagglutinin undergoes an irreversible conformational change (J.J. Skehel, P. M. Bayley, E. B. Brown, S. R. Martin, M. D. Waterfield, J. M. White, I. A. Wilson, and D. C. Wiley (1982). Proc. Natl. Acad. Sci. USA 79, 968-972) which parallels the appearance of fusion activity of this molecule. This paper describes experiments which explore the conformational change using a panel of monoclonal antibodies which define four of the major antigenic sites of this protein. The results indicate that three of the major antigenic sites of hemagglutinin undergo changes when exposed to acid pH. These changes have little effect on the binding avidity of influenza virus to glycophorin, the major receptor present on the red blood cell surface. These findings have been used to postulate a mechanism where the molecule flexes around a central region resulting in rearrangement in space of its component domains on exposure to low pH.
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PMID:Antigenic determinants of influenza virus hemagglutinin. XI. Conformational changes detected by monoclonal antibodies. 240 71

The effects of lysophosphatidylcholine (lysoPC) on human erythrocyte (RBC) ghost morphology, transmembrane protein and lipid lateral mobilities, and membrane lipid composition were studied in order to elucidate mechanisms by which lysoPC immobilizes ghost membrane components [Golan, D. E., Brown, C. S., Cianci, C. M. L., Furlong, S. T., & Caulfield, J. P. (1986) J. Cell Biol. 103, 819-828]. Under standardized conditions 1.0-1.5 micrograms/mL egg lysoPC lysed 50% of RBCs and induced, in some ghosts, the formation of large patches of wrinkled membrane. Patches exhibited complete immobilization of glycophorin and band 3 and partial immobilization of the phospholipid analogue fluorescein phosphatidylethanolamine (Fl-PE), whereas adjacent smooth membrane areas manifested only partial immobilization of proteins and no immobilization of Fl-PE. Supralytic concentrations of lysoPC induced both progressive, homogeneous wrinkling of RBC ghost membranes and concentration-dependent decreases in the lateral mobilities of glycophorin, band 3, and Fl-PE. Complete immobilization of glycophorin and band 3 occurred at 8.4 micrograms/mL lysoPC and of Fl-PE at 16.8 micrograms/mL lysoPC. Monopalmitoylphosphatidylcholine (MPPC), the major component of egg lysoPC, induced both membrane wrinkling and a concentration-dependent decrease in Fl-PE mobility, with complete immobilization at 10 micrograms/mL. Other synthetic lysoPCs did not completely immobilize Fl-PE, although some caused membrane wrinkling. MPPC was incorporated into ghost membranes with a linear dependence (r = 0.97) on MPPC concentration. Relative to total membrane lipid, the lysoPC mole fraction increased from 0.2 +/- 0.1% at 0 micrograms/mL MPPC to 25 +/- 2% at 16 micrograms/mL MPPC.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Monopalmitoylphosphatidylcholine incorporation into human erythrocyte ghost membranes causes protein and lipid immobilization and cholesterol depletion. 340 42

Monoclonal antibodies against lymphocyte glycoproteins have been used to identify the membrane molecules which bind peanut (PNA) and Helix pomatia (HPA) agglutinins and cap spontaneously on the uropod of polarized rat and mouse thymocytes. On the basis of co-capping experiments and radiolabelling of isolated glycoproteins after sodium dodecylsulfate polyacrylamide electrophoresis (SDS-PAGE), the major HPA- and PNA-binding sialoglycoprotein (with an apparent molecular weight of about 105 K; (1K = 10(3] 125-135 K after neuraminidase treatment) appears to be identical with the thymocyte glycophorin-like protein described by Brown et al. [11] and to correspond to the spontaneously capping component. Components of the mouse T200 (or rat 'leukocyte common antigen') differentiation antigen group also bind PNA (and partially HPA), but are unable to cap spontaneously. Some similarities in the redistribution behaviour of thymocyte and erythrocyte glycoproteins are discussed.
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PMID:Lectin-binding and spontaneous capping characteristics of the thymocyte glycophorin-like glycoprotein. 660 31