Light and electron microscopical localization of concanavalin A lectin binding sites in rat epiphyseal chondrocytes

1987 ◽  
Vol 19 (1) ◽  
pp. 7-14 ◽  
Author(s):  
A. Velasco ◽  
J. Hidalgo
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Lectin Binding ◽  
Microscopical Localization ◽  
Electron Microscopical ◽  
Lectin Binding Sites

scholarly journals Schistosomula of Schistosoma mansoni clear concanavalin A from their surface by sloughing.

1982 ◽  
Vol 94 (2) ◽  
pp. 355-362 ◽  
Author(s):  
J C Samuelson ◽  
J P Caulfield ◽  
J R David
Keyword(s):  
Schistosoma Mansoni ◽  
Concanavalin A ◽  
Binding Sites ◽  
Culture Medium ◽  
Culture Media ◽  
Lectin Binding ◽  
Defined Medium ◽  
Con A ◽  
Sds Page ◽  
Lectin Binding Sites

The lectin concanavalin A (Con A) was used as a model probe to study the behavior of molecules bound to the surface of recently transformed schistosomula of Schistosoma mansoni. Con A binding was saturable (150-180 pg/organism) and specifically competed by alpha-methyl mannoside. Both FITC-Con A and 125-I-Con A were lost from the surface of schistosomula with a halftime of 8-10 h in culture in defined medium. A comparable decrease in the binding of Con A to schistosomula cultured and then labeled with the lectin indicated that the labeling procedure itself was not inducing the observed change. Internalization of Con A was not seen by either fluorescence microscopy or electron microscope radioautography. In addition, 70-80% of the radioactivity lost from the parasite was recoverable by TCA precipitation from the culture medium as intact Con A (27,000 mol wt on SDS PAGE). Thus, the mechanism of clearance of bound Con A from the surface of cultured schistosomula is apparently by sloughing of Con A molecules intact into the culture media and not by endocytosis and degradation. Con A binding sites, visualized with hemocyanin by scanning electron microscopy, appeared homogeneously distributed over the surface of schistosomula when organisms were labeled at 4 degree C or after fixation with glutaraldehyde. However, Con A and hemocyanin formed aggregates on the surface of schistosomula when labeling was performed at 37 degrees C, which suggests that lectin binding sites have lateral mobility within the plane of the membrane. These aggregates are likely independent of metabolism by the parasite because aggregation also occurs on the surface of organisms killed with azide.

Surface structure of the golgi complex and identification of concanavalin-A binding sites

1978 ◽  
Vol 36 (2) ◽  
pp. 246-247
Author(s):  
J.M. Sturgess ◽  
M. Teitelman ◽  
M.A. Moscarello
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Golgi Complex ◽  
Concanavalin A ◽  
Binding Sites ◽  
Lectin Binding ◽  
Bicarbonate Buffer ◽  
Sodium Phosphate Buffer ◽  
Scanning Electron ◽  
Lectin Binding Sites

Scanning electron microscopy has been applied to study the surface ultrastructure of the Golgi complex and labelling techniques have been developed to investigate the distribution of lectin-binding sites on the membrane surfaces. The study is based on the examination of Golgi-rich fractions, isolated by homogenisation and differential centrifugation of rat liver. The membranes are fixed in suspension with 1% glutaraldehyde in 0.1 M sodium phosphate buffer, pH 7.4 for 60 mins and then rinsed in distilled water. For scanning electron microscopy, a thin film of membrane is frozen rapidly on coverglasses using liquid Freon 22, cooled by liquid nitrogen and dried in vacuo at -60°C. Membranes are coated with approximately 100 Å gold in a sputter coater and examined at 20 kV in a JEOL JSM-35U scanning electron microscope. For transmission electron microscopy, membranes are processed as described previously. For examination of lectin binding sites, isolated Golgi membranes are washed in sodium bicarbonate buffer, fixed in glutaraldehyde, incubated with concanavalin A (Con A), rinsed in buffer and then incubated with hemocyanin1.

scholarly journals Peroxidase and gold complexes of lectins for double labeling of surface-binding sites by electron microscopy.

1977 ◽  
Vol 25 (10) ◽  
pp. 1181-1184 ◽  
Author(s):  
J Roth ◽  
M Wagner
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Concanavalin A ◽  
Binding Sites ◽  
Lectin Binding ◽  
Helix Pomatia ◽  
Surface Binding ◽  
Double Labeling ◽  
Membrane Bound ◽  
Lectin Binding Sites

Double labeling experiments were performed for visualization of the binding sites of Concanavalin A and anti-AHel (the lectin from Helix pomatia). The anti-AHel was labeled with the colloidal gold whereas the membrane bound Concanavalin A was demonstrated by an affinity technique using horseradish peroxidase. The two markers used could be clearly distinguished electron microscopically. The specificity of the cell surface double labeling was demonstrated in the control experiments. A topological distinct localization of the both lectin-binding sites is evident.

Differences in Glycoconjugates of Adrenocorticotropic Hormone-secretory Granules between Nonadenomatous Pituitary Cells and Adenoma Cells as Detected by Double Labeling

Neurosurgery ◽  
1988 ◽  
Vol 23 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Tomokatsu Hori ◽  
Fumiaki Nishiyama ◽  
Yuichi Anno ◽  
Satoshi Tanaka ◽  
Takashi Watanabe ◽  
...  
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Pituitary Adenomas ◽  
Adrenocorticotropic Hormone ◽  
Secretory Granules ◽  
Lectin Binding ◽  
Pituitary Cells ◽  
Human Pituitary ◽  
Pituitary Tissue ◽  
Lectin Binding Sites

ABSTRACT Lectin binding sites of adrenocorticotropic hormone (ACTH) secretory granules of human pituitary adenomas and of nonadenomatous pituitary tissue adjacent to adenomas were studied by postembedding immunocytochemical doublestaining on ultrathin sections followed by electron microscopy. The specific hormones produced by the secretory granules were identified by labeling one side of the section with anti-human pituitary hormone antibodies conjugated to gold particles. Simultaneously, the other side was labeled with horseradish peroxidase-lectin to reveal lectin binding sites. Specimens were obtained from four human ACTH-producing pituitary adenomas and from nonadenomatous pituitary tissue surrounding three other adenomas. The four ACTH-producing adenomas showed either weak or negative reactions with concanavalin A, whereas the nonadenomatous ACTH-producing pituitary cells reacted strongly with concanavalin A. Moreover, ACTH secretory granules were significantly larger in the nonadenomatous cells than in adenoma cells. Differences in biochemical structure and ultrastructure between nonadenomatous (normal) pituitary cells and adenoma cells secreting the same specific hormones were demonstrated, and the clinical implications of the results were discussed.

Lectin-binding sites in chick limb buds

1989 ◽  
Vol 27 ◽  
pp. 82
Author(s):  
M. Narita ◽  
K. Yamashita ◽  
M. Yasuda
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Limb Buds ◽  
Lectin Binding Sites

Ultrastructural demonstration of lectin binding sites in the Golgi apparatus of rat epiphyseal chondrocytes

1988 ◽  
Vol 89 (2) ◽  
pp. 177-184 ◽  
Author(s):  
A. Velasco ◽  
J. Hidalgo ◽  
M. M�ller ◽  
G. Garcia-Herdugo
Keyword(s):  
Golgi Apparatus ◽  
Binding Sites ◽  
Lectin Binding ◽  
Lectin Binding Sites

Lectin binding sites of the mouse ovary, intraovarian and ovulated ova

1984 ◽  
Vol 80 (6) ◽  
pp. 527-533 ◽  
Author(s):  
T. -C. Wu ◽  
M. -C. Lee ◽  
Y. -J. Wan ◽  
I. Damjanov
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Mouse Ovary ◽  
Lectin Binding Sites
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