The distribution and mobility of anionic sites on the surface of human placental syncytial trophoblast

1981 ◽  
Vol 199 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Barry F. King
Keyword(s):  
Anionic Sites ◽  
Syncytial Trophoblast

Trophoblast Cell Membrane Interactions at Implantation

1970 ◽  
Vol 28 ◽  
pp. 310-311
Author(s):  
A. C. Enders
Keyword(s):  
Epithelial Cells ◽  
Cell Membrane ◽  
Membrane Fusion ◽  
Trophoblast Cell ◽  
Membrane Interactions ◽  
Uterine Epithelial Cells ◽  
Functional Complex ◽  
Cytotrophoblast Cells ◽  
Complex Relationships ◽  
Syncytial Trophoblast

The alteration in membrane relationships seen at implantation include 1) interaction between cytotrophoblast cells to form syncytial trophoblast and addition to the syncytium by subsequent fusion of cytotrophoblast cells, 2) formation of a wide variety of functional complex relationships by trophoblast with uterine epithelial cells in the process of invasion of the endometrium, and 3) in the case of the rabbit, fusion of some uterine epithelial cells with the trophoblast.Formation of syncytium is apparently a membrane fusion phenomenon in which rapid confluence of cytoplasm often results in isolation of residual membrane within masses of syncytial trophoblast. Often the last areas of membrane to disappear are those including a desmosome where the cell membranes are apparently held apart from fusion.

Expression of Anionic Sites at the Dermoepibolic Junction

1987 ◽  
Vol 88 (1) ◽  
pp. 94-96
Author(s):  
Motomu Manabe ◽  
Shigaku Ikeda ◽  
Tsutomu Muramatsu ◽  
Hideoki Ogawa
Keyword(s):  
Anionic Sites

Anionic sites on developing rat photoreceptors

1985 ◽  
Vol 17 (2) ◽  
pp. 165
Author(s):  
E. Marksmer ◽  
I. Nir ◽  
D. Cohen
Keyword(s):  
Anionic Sites ◽  
Developing Rat

scholarly journals Potentiation effect of choline esters on choline-catalysed decarbamoylation of dimethylcarbamoyl-acetylcholinesterase

1992 ◽  
Vol 284 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Y B Kim ◽  
C H Jung ◽  
S J Choi ◽  
W J Seo ◽  
S H Cha ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Quaternary Ammonium ◽  
Acyl Chain ◽  
Requirement Analysis ◽  
Ester Bond ◽  
Choline Ester ◽  
Anionic Sites ◽  
Structural Requirement ◽  
Potentiation Effect ◽  
Choline Esters

The choline esters potentiated the choline-catalysed decarbamoylation of dimethylcarbamoyl-acetylcholinesterase in proportion to the length of acyl group, although esters containing an acyl chain longer than the hexanoyl group exhibited a corresponding decrease in the potentiation. In structural requirement analysis it was found that both the quaternary ammonium moiety and the ester bond were important for the effective acceleration of choline-catalysed decarbamoylation. In general, the respective thiocholine ester was found to be more effective than the corresponding choline ester. Whereas the binding affinity (Ka) of choline in the decarbamoylation was not significantly altered, the maximum decarbamoylation rate (kr(max.)) of choline was greatly enhanced in the presence of choline esters or thiocholine esters. Along with the above observation, the isotope solvent effect, the effect of ionic strength and the antagonism studies demonstrate that the choline esters or thiocholine esters may interact with one of peripheral anionic sites, and thereby make the choline-catalysed decarbamoylation more favourable.

Distribution of anionic sites on surface of B cell granule and plasma membranes: a study using cationic ferritin

1977 ◽  
Vol 27 (1) ◽  
pp. 289-301
Author(s):  
S.L. Howell ◽  
M. Tyhurst
Keyword(s):  
B Cell ◽  
Plasma Membranes ◽  
Calcium Concentration ◽  
Anionic Sites ◽  
Neuraminidase Treatment ◽  
Visual Probe ◽  
Cell Plasma ◽  
Granule Membrane ◽  
Pancreatic B Cells ◽  
Storage Granules

The distribution of anionic sites on the membranes of rat pancreatic B cells and of their storage granules has been studied by the use of a visual probe of cationic ferritin. Membranes of isolated storage granules possessed a net negative charge which was apparently evenly distributed; the number of anionic sites was not markedly altered by prior incubation of the granules with neuraminidase or with 10(−5) to 2 X 10(−3) M calcium chloride. Distribution of charges along B cell plasma membranes was less uniform but was similarly unaffected by alterations of calcium concentration, or by neuraminidase treatment. However, during the fusion of plasma membrane and granule membrane which occurs in exocytosis, the emerging granule membrane was found to be devoid of anionic sites. The implications of these findings for the regulation of insulin secretion by exocytosis are discussed.

scholarly journals Recovery of Anionic Sites of the Glomerular Basement Membrane after Their Disappearance by the Cationic Probe Molecule

Nephron ◽  
1991 ◽  
Vol 59 (3) ◽  
pp. 500-501 ◽  
Author(s):  
Ashio Yoshimura ◽  
Terukuni Ideura ◽  
Kiyoko Nakano ◽  
Hiroaki Oniki ◽  
Yuichi Sugisaki ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Probe Molecule ◽  
Anionic Sites

Cation exchange in cell walls of gram-positive bacteria

1976 ◽  
Vol 22 (7) ◽  
pp. 975-982 ◽  
Author(s):  
Robert E. Marquis ◽  
Kathleen Mayzel ◽  
Edwin L. Carstensen
Keyword(s):  
Cation Exchange ◽  
Cell Walls ◽  
Divalent Cations ◽  
Teichoic Acid ◽  
Dry Weight ◽  
High Ionic Strength ◽  
Monovalent Cations ◽  
Anionic Sites ◽  
Gram Positive Bacteria ◽  
Anionic Groups

The relative affinities of various cations for anionic sites in isolated, bacterial cell walls were assessed by means of a technique involving displacement of one cation by another. The affinity series determined was [Formula: see text]. High affinity was correlated with low mobility of the bound ions in an electric field. The net cation-exchange capacities of walls isolated from a variety of bacteria were estimated by preparing the magnesium forms of the walls, washing them well with deionized water to remove supernumerary ions, and then completely displacing the magnesium with Na+ or H+. Total amounts of magnesium displaced varied from 73 μmol per gram dry weight, for walls of the teichoic acid-deficient 52A5 strain of Staphylococcus aureus to about 520 μmol per gram for Bacillus megaterium KM walls. The amount of displacable magnesium was inversely related to the physical compactness of the walls, except for walls of Streptococcus mutans GS-5. It was found that magnesium or calcium ions can each neutralize, or pair with, two anionic groups in walls suspended in ion-deficient media. Previous work had indicated that these ions may pair with only one anionic group at high ionic strength. Therefore, it appeared that there is a great deal of flexibility in the arrangement of charged groups in the wall. It was concluded also that for cells growing in commonly used laboratory media, which generally contain large excesses of monovalent versus divalent cations, there is a mix of small, cationic counterions in the wall and that monovalent cations may predominate even though the wall has higher affinity for divalent ions.

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