scholarly journals Freeze-fracture cytochemistry of rat glomerular capillary tuft. Determination of wheat germ agglutinin binding sites and localization of anionic charges.

1987 ◽  
Vol 35 (12) ◽  
pp. 1389-1399 ◽  
Author(s):  
J Chevalier ◽  
M D Appay ◽  
X Y Wang ◽  
J Bariety ◽  
P Pinto Da Silva
Keyword(s):  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Freeze Fracture ◽  
Glomerular Capillary

scholarly journals Subfractionation of cardiac sarcolemma with wheat-germ agglutinin

1989 ◽  
Vol 264 (3) ◽  
pp. 885-892 ◽  
Author(s):  
J H M Charuk ◽  
S Howlett ◽  
M Michalak
Keyword(s):  
Plasma Membrane ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Freeze Fracture ◽  
Protein Composition ◽  
Tubular Structures ◽  
Electron Microscopic ◽  
Cardiac Sarcolemma ◽  
Inside Out

The properties of highly purified bovine cardiac sarcolemma subfractionated with the lectin, wheat-germ agglutinin (WGA) were studied. Two different membrane subfractions were isolated, one which was agglutinated in the presence of 1.0 mg of WGA/mg of protein (WGA+ vesicles) and a second fraction which failed to agglutinate (WGA- vesicles). These two membrane fractions had quantitatively different rates of Na+/K+-dependent, ouabain-sensitive ATPase and Na+/Ca2+ exchange activities, yet a similar protein composition, which suggests that they were both derived from the plasma membrane. WGA- vesicles had a decreased number of [3H]quinuclidinyl benzilate-binding sites and no detectable [3H]nitrendipine-binding sites. Electron-microscopic and freeze-fracture analysis showed that the WGA+ fraction was composed of typical spherical sarcolemmal vesicles, whereas the WGA- fraction primarily contained elongated tubular structures suggestive of the T-tubule vesicles which were previously isolated from skeletal muscle. Assays of marker enzymes revealed that these fractions were neither sarcoplasmic reticulum nor plasma membrane from endothelial cells. Moreover, WGA agglutination did not result in the separation of right-side-out and inside-out vesicles. On the basis of these findings we propose that the WGA+ fraction corresponds to highly purified sarcolemma, whereas the WGA- fraction may be derived from T-tubule membranes.

scholarly journals Freeze-fracture cytochemistry: partition of glycophorin in freeze-fractured human erythrocyte membranes.

1982 ◽  
Vol 93 (2) ◽  
pp. 463-469 ◽  
Author(s):  
P P da Silva ◽  
M R Torrisi
Keyword(s):  
Human Erythrocyte ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Transmembrane Protein ◽  
Freeze Fracture ◽  
Membrane Skeleton ◽  
Erythrocyte Membranes ◽  
Con A ◽  
Human Erythrocyte Membranes

Thin-section and critical-point-dried fracture-labeled preparations are used to determine the distribution and partition of glycophorin-associated wheat germ agglutinin (WGA) binding sites over protoplasmic and exoplasmic faces of freeze-fractured human erythrocyte membranes. Most wheat germ agglutinin binding sites are found over exoplasmic faces. Label is sparse over the protoplasmic faces. These results contrast with previous observations of the partition of band 3 component where biochemical analysis and fracture-label of concanavalin A (Con A) binding sites show preferential partition of this transmembrane protein with the protoplasmic face. Presence of characteristic proportions of WGA and Con A binding sites over each fracture face is interpreted to indicate the operation of a stochastic process during freeze-fracture. This process appears modulated by the relative expression of each transmembrane protein at either surface as well as by their association to components of the erythrocyte membrane skeleton.

scholarly journals Freeze-fracture cytochemistry: localization of wheat-germ agglutinin and concanavalin A binding sites on freeze-fractured pancreatic cells.

1981 ◽  
Vol 91 (2) ◽  
pp. 361-372 ◽  
Author(s):  
P Pinto da Silva ◽  
M R Torrisi ◽  
B Kachar
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Concanavalin A ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Freeze Fracture ◽  
Combined Application ◽  
Pancreatic Cells ◽  
Critical Point Drying

The combined application of thin-section and critical-point-drying "fracture-label" is used to determine the pattern of distribution and partition of wheat-germ agglutinin and concanavalin A binding sites on the membrane faces of freeze-fractured exocrine and endocrine rat pancreatic cells. Whereas the exoplasmic face of plasma membrane is preferentially labeled by both lectins, the endoplasmic reticulum and nuclear envelope are strongly and uniformly labeled by concanavalin A but not by wheat-germ agglutinin. The results support current views in the glycosylation of membrane proteins and do not support the backflow of sialidated glycoproteins to the endoplasmic reticulum.

scholarly journals Interaction of rice (Oryza sativa) lectin with N-acetylglucosaminides. Fluorescence studies

1985 ◽  
Vol 229 (3) ◽  
pp. 687-692 ◽  
Author(s):  
F Tabary ◽  
J P Frénoy
Keyword(s):  
Oryza Sativa ◽  
Binding Sites ◽  
Wheat Germ ◽  
Equilibrium Dialysis ◽  
Blue Shift ◽  
Association Constants ◽  
Fluorescence Studies ◽  
Saccharide Binding ◽  
Binding Enthalpy

The interaction of lectin isolated from rice (Oryza sativa) embryos with N-acetylglucosaminides was studied by equilibrium dialysis and fluorescence. Equilibrium dialysis with 4-methylumbelliferyl-(GlcNac)2 showed that rice lectin (Mr 38000) contains four equivalent saccharide-binding sites. Addition of the N-acetylglucosaminides GlcNac, (GlcNac)2 and (GlcNac)3 enhanced the intrinsic fluorescence of rice lectin and this was accompanied by a 10nm blue-shift of its maximum fluorescence with (GlcNac)2 and (GlcNac)3. These changes in intensity allowed determination of the association constants, which increased with the number of saccharide units: at 20 degrees C, Ka = (1.3 +/- 0.1) X 10(3), (5.1 +/- 0.4) X 10(4) and (2.6 +/- 0.1) X 10(5) M−1 for GlcNac, (GlcNac)2 and (GlcNac)3 respectively. The binding enthalpy, delta H0, for the three glucosaminides were very low and ranged from −12.1 to −20.6 kJ X mol-1. The results are compared with those obtained with wheat-germ agglutinin, another GlcNac-specific gramineaous lectin.

scholarly journals Compartmentalization of intracellular membrane glycocomponents is revealed by fracture-label.

1984 ◽  
Vol 98 (1) ◽  
pp. 29-34 ◽  
Author(s):  
M R Torrisi ◽  
P Pinto da Silva
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Secretory Granules ◽  
The Other ◽  
Rat Tissues ◽  
Intracellular Membrane ◽  
Definition Of

We used thin-section fracture-label to determine the distribution of wheat-germ agglutinin binding sites in intracellular membranes of secretory and nonsecretory rat tissues as well as in human leukocytes. In all cases, analysis of the distribution of wheat germ agglutinin led to the definition of two endomembrane compartments: one, characterized by absence of the label, includes the membranes of mitochondria and peroxisomes as well as those of the endoplasmic reticulum and nuclear envelope; the other, strongly labeled, comprises the membrane of lysosomes, phagocytic vacuoles, and secretory granules, as well as the plasma membrane. The Golgi apparatus was weakly labeled in all studied tissues.

Wheat germ agglutinin binding sites in the organ of Corti as revealed by lectin-gold labeling

1987 ◽  
Vol 27 (3) ◽  
pp. 239-244 ◽  
Author(s):  
Masayoshi Tachibana ◽  
Hiroyuki Morioka ◽  
Mitsuo Machino ◽  
Masaki Yoshimatsu ◽  
Osamu Mizukoshi
Keyword(s):  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Organ Of Corti

scholarly journals Expression of 5′Nucleotidase Activity and Wheat-Germ Agglutinin Binding Sites in Mononuclear Phagocytes From Bone Marrow Cultures

1985 ◽  
Vol 37 (3) ◽  
pp. 263-277 ◽  
Author(s):  
R. de Water ◽  
J.W.M. van der Meer ◽  
J.M. van't Noordende ◽  
J.J.M. Onderwater ◽  
J.S. van de Gevel ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Mononuclear Phagocytes ◽  
Nucleotidase Activity ◽  
Bone Marrow Cultures ◽  
Marrow Cultures
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