Peptide-Membrane Interactions Affect the Inhibitory Potency and Selectivity of Spider Toxins ProTx-II and GpTx-1

2018 ◽  
Vol 14 (1) ◽  
pp. 118-130 ◽  
Author(s):  
Nicole Lawrence ◽  
Bin Wu ◽  
Joseph Ligutti ◽  
Olivier Cheneval ◽  
Akello Joanna Agwa ◽  
...  
Keyword(s):  
Membrane Interactions ◽  
Inhibitory Potency ◽  
Spider Toxins

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.

Heparin Counteracts the Antiaggregating Effect of Prostacyclin by Potentiating Platelet Aggregation

1983 ◽  
Vol 49 (02) ◽  
pp. 081-083 ◽  
Author(s):  
Vittorio Bertelé ◽  
Maria Carla Roncaglioni ◽  
Maria Benedetta Donati ◽  
Giovanni de Gaetano
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Specific Interaction ◽  
Inhibitory Effect ◽  
Effective Inhibitor ◽  
Inhibitory Potency ◽  
Human Platelet Aggregation

SummaryIt has recently been reported that heparin neutralizes the inhibitory effect of prostacyclin (PGI2) on human platelet aggregation. The mechanism of this interaction has not yet been unequivocally established. We present here evidence that heparin (Liquemin Roche) does not react directly with PGI2 but counteracts its inhibitory effect by potentiating platelet aggregation. In the absence of heparin, PGI2 was a less effective inhibitor of platelet aggregation induced by the combination of ADP and serotonin than by ADP alone. Moreover, the inhibitory effect of PGI2 was similarly reduced when increasing the concentrations of ADP (in the absence of heparin). The lack of a specific interaction between heparin and PGI2 is supported by the observation that, in the presence of heparin, other prostaglandins such as PGD2 and PGE1, and a non-prostanoid compound such as adenosine also appeared to lose their inhibitory potency. It is concluded that heparin opposes platelet aggregation inhibitory effect of PGI2 by enhancement of platelet aggregation.

Nanoparticle-plasma Membrane Interactions: Thermodynamics, Toxicity and Cellular Response

2020 ◽  
Vol 27 (20) ◽  
pp. 3330-3345
Author(s):  
Ana G. Rodríguez-Hernández ◽  
Rafael Vazquez-Duhalt ◽  
Alejandro Huerta-Saquero
Keyword(s):  
Gene Expression ◽  
Immune Responses ◽  
Cellular Response ◽  
Cellular Level ◽  
Membrane Interactions ◽  
Daily Lives ◽  
Cellular Physiology ◽  
Associated Proteins ◽  
First Contact ◽  
Insight Into

Nanomaterials have become part of our daily lives, particularly nanoparticles contained in food, water, cosmetics, additives and textiles. Nanoparticles interact with organisms at the cellular level. The cell membrane is the first protective barrier against the potential toxic effect of nanoparticles. This first contact, including the interaction between the cell membranes -and associated proteins- and the nanoparticles is critically reviewed here. Nanoparticles, depending on their toxicity, can cause cellular physiology alterations, such as a disruption in cell signaling or changes in gene expression and they can trigger immune responses and even apoptosis. Additionally, the fundamental thermodynamics behind the nanoparticle-membrane and nanoparticle-proteins-membrane interactions are discussed. The analysis is intended to increase our insight into the mechanisms involved in these interactions. Finally, consequences are reviewed and discussed.

CAMP-Membrane Interactions Using Fluorescence Spectroscopy

BIO-PROTOCOL ◽  
2013 ◽  
Vol 3 (15) ◽  
Author(s):  
Ron Saar-Dover ◽  
Yechiel Shai
Keyword(s):  
Fluorescence Spectroscopy ◽  
Membrane Interactions

Comparison of the Potency of 8-L-Arginine, 8-D-Arginine and 8-D-Homoarginine Vasopressin Analogs with Substituted Phenylalanine in Position 2

1994 ◽  
Vol 59 (6) ◽  
pp. 1439-1450 ◽  
Author(s):  
Miroslava Žertová ◽  
Jiřina Slaninová ◽  
Zdenko Procházka
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Basic Amino Acid ◽  
The Other ◽  
Side Chain ◽  
Inhibitory Potency ◽  
Phase Synthesis ◽  
Other Hand ◽  
Order Of Magnitude

An analysis of the uterotonic potencies of all analogs having substituted L- or D-tyrosine or -phenylalanine in position 2 and L-arginine, D-arginine or D-homoarginine in position 8 was made. The series of analogs already published was completed by the solid phase synthesis of ten new analogs having L- or D-Phe, L- or D-Phe(2-Et), L- or D-Phe(2,4,6-triMe) or D-Tyr(Me) in position 2 and either L- or D-arginine in position 8. All newly synthesized analogs were found to be uterotonic inhibitors. Deamination increases both the agonistic and antagonistic potency. In the case of phenylalanine analogs the change of configuration from L to D in position 2 enhances the uterotonic inhibition for more than 1 order of magnitude. The L to D change in position 8 enhances the inhibitory potency negligibly. Prolongation of the side chain of the D-basic amino acid in position 8 seems to decrease slightly the inhibitory potency if there is L-substituted amino acid in position 2. On the other hand there is a tendency to the increase of the inhibitory potency if there is D-substituted amino acid in position 2.

Sign in / Sign up

Export Citation Format

Share Document