Cell Membrane Preparation

2016 ◽  
Author(s):  
John Proudfoot ◽  
Olivier Nosjean ◽  
Jan Blanchard ◽  
John Wang ◽  
Dominique Besson ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Membrane Preparation ◽  
Cell Membrane Preparation

Processing of surfactant protein B proprotein by a cathepsin D-like protease

1992 ◽  
Vol 263 (1) ◽  
pp. L95-L103 ◽  
Author(s):  
T. E. Weaver ◽  
S. Lin ◽  
B. Bogucki ◽  
C. Dey
Keyword(s):  
Epithelial Cell ◽  
Cell Membrane ◽  
Cathepsin D ◽  
Surfactant Protein ◽  
Membrane Preparation ◽  
Aspartyl Protease ◽  
Type Ii ◽  
Surfactant Protein B ◽  
Type Ii Cell ◽  
Cell Membrane Preparation

Surfactant protein B (SP-B) is a hydrophobic peptide of relative molecular weight (M(r)) = 8,000 that is associated with pulmonary surfactant phospholipids. SP-B is synthesized by the alveolar type II epithelial cell as a proprotein of M(r) = 42,000 which requires at least two proteolytic cleavages to generate the 79 residue mature SP-B peptide. We have previously reported that cleavage of the NH2-terminal propeptide, to generate a processing intermediate of M(r) = 25,000, occurs in close temporal approximation to secretion. In the present study we demonstrate that SP-B proprotein, isolated from stably transfected Chinese hamster ovary cells, is processed to M(r) = 25,000 by a crude type II cell membrane fraction but not by intact type II cells or type II cell conditioned media. In vitro processing of the proprotein by the type II cell membrane preparation resulted in release of a single peptide of M(r) = 16,000–17,000, which was detected by antiserum directed against antigenic epitopes in propeptide of the precursor. SP-B processing activity was extracted by Na2CO3 lysis of the type II cell membrane preparation, had a pH optimum of 5.0–6.0, and was inhibited by 10(-7) M pepstatin A, suggesting that the NH2-terminal peptide of the precursor is cleaved by an aspartyl protease. Consistent with this hypothesis, processing of SP-B by a crude type II cell membrane preparation was blocked by antiserum directed against the aspartyl protease cathepsin D; further, purified cathepsin D efficiently processed the SP-B precursor to M(r) = 25,000. Collectively these results suggest that cleavage of the NH2-terminal propeptide of the SP-B precursor is mediated by cathepsin D or a cathepsin D-like protease localized within the secretory pathway of the type II epithelial cell.

Stimulatory effect of vanadate on (Na+ + K+)-ATPase activity and on 3H-ouabain-binding in a cat heart cell membrane preparation

Nature ◽  
1979 ◽  
Vol 278 (5703) ◽  
pp. 459-461 ◽  
Author(s):  
ERLAND ERDMANN ◽  
WOLFGANG KRAWIETZ ◽  
GUNTHER PHILIPP ◽  
INGELORE HACKBARTH ◽  
WILHELM SCHMITZ ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Atpase Activity ◽  
Membrane Preparation ◽  
Heart Cell ◽  
Ouabain Binding ◽  
Heart Cell Membrane ◽  
Cell Membrane Preparation ◽  
Cat Heart

scholarly journals Identification of diphtheria toxin receptor and a nonproteinous diphtheria toxin-binding molecule in Vero cell membrane.

1988 ◽  
Vol 107 (2) ◽  
pp. 511-519 ◽  
Author(s):  
E Mekada ◽  
Y Okada ◽  
T Uchida
Keyword(s):  
Cell Membrane ◽  
Vero Cell ◽  
Diphtheria Toxin ◽  
Vero Cells ◽  
Binding Activity ◽  
Membrane Preparation ◽  
Toxin Binding ◽  
Surface Receptor ◽  
Toxin Receptor ◽  
Cell Membrane Preparation

Two substances possessing the ability to bind to diphtheria toxin (DT) were found to be present in a membrane fraction from DT-sensitive Vero cells. One of these substances was found on the basis of its ability to bind DT and inhibit its cytotoxic effect. This inhibitory substance competitively inhibited the binding of DT to Vero cells. However this inhibitor could not bind to CRM197, the product of a missense mutation in the DT gene, and did not inhibit the binding of CRM197 to Vero cells. Moreover, similar levels of the inhibitory activity were observed in membrane fractions from DT-insensitive mouse cells, suggesting the inhibitor is not the DT receptor which is specifically present in DT-sensitive cells. The second DT-binding substance was found in the same Vero cell membrane preparation by assaying the binding of 125I-labeled CRM197. Such DT-binding activity could not be observed in membrane preparation from mouse L cells. From competition studies using labeled DT and CRM proteins, we conclude that this binding activity is due to the surface receptor for DT. Treatment of these substances with several enzymes revealed that the inhibitor was sensitive to certain RNases but resistant to proteases, whereas the DT receptor was resistant to RNase but sensitive to proteases. The receptor was solubilized and partially purified by chromatography on CM-Sepharose column. Immunoprecipitation and Western blotting analysis of the partially purified receptor revealed that a 14.5-kD protein is the DT receptor, or at least a component of it.

Binding of Insulin to a Muscle Cell Membrane Preparation

Nature ◽  
1963 ◽  
Vol 197 (4870) ◽  
pp. 878-880 ◽  
Author(s):  
P. M. EDELMAN ◽  
S. L. ROSENTHAL ◽  
I. L. SCHWARTZ
Keyword(s):  
Cell Membrane ◽  
Muscle Cell ◽  
Membrane Preparation ◽  
Cell Membrane Preparation ◽  
Muscle Cell Membrane

Sarcolemmal permeability changes during early myocardial anoxia

1978 ◽  
Vol 36 (2) ◽  
pp. 642-643
Author(s):  
M. Ashraf ◽  
L. Landa ◽  
L. Nimmo ◽  
C. M. Bloor
Keyword(s):  
Cell Membrane ◽  
Membrane Permeability ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Cell Membrane Permeability ◽  
Enzyme Release ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Sarcolemmal Permeability ◽  
Membrane Changes

Following coronary artery occlusion, the myocardial cells lose intracellular enzymes that appear in the serum 3 hrs later. By this time the cells in the ischemic zone have already undergone irreversible changes, and the cell membrane permeability is variably altered in the ischemic cells. At certain stages or intervals the cell membrane changes, allowing release of cytoplasmic enzymes. To correlate the changes in cell membrane permeability with the enzyme release, we used colloidal lanthanum (La+++) as a histological permeability marker in the isolated perfused hearts. The hearts removed from sprague-Dawley rats were perfused with standard Krebs-Henseleit medium gassed with 95% O2 + 5% CO2. The hypoxic medium contained mannitol instead of dextrose and was bubbled with 95% N2 + 5% CO2. The final osmolarity of the medium was 295 M osmol, pH 7. 4.

Flagellar Attachment in Selected Trypanosomes

1973 ◽  
Vol 31 ◽  
pp. 496-497
Author(s):  
J. J. Paulin
Keyword(s):  
Cell Membrane ◽  
Lateral Surface ◽  
The Body ◽  
Flagellar Pocket ◽  
Integral Component ◽  
Free Flagellum ◽  
Flagellar Axoneme

Movement in epimastigote and trypomastigote stages of trypanosomes is accomplished by planar sinusoidal beating of the anteriorly directed flagellum and associated undulating membrane. The flagellum emerges from a bottle-shaped depression, the flagellar pocket, opening on the lateral surface of the cell. The limiting cell membrane envelopes not only the body of the trypanosome but is continuous with and insheathes the flagellar axoneme forming the undulating membrane. In some species a paraxial rod parallels the axoneme from its point of emergence at the flagellar pocket and is an integral component of the undulating membrane. A portion of the flagellum may extend beyond the anterior apex of the cell as a free flagellum; the length is variable in different species of trypanosomes.

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.

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