Interactions between ions and the axon plasma membrane: Effects of cations and anions on the axonal cholinergic binding macromolecule of lobster nerves

1973 ◽  
Vol 11 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Jeffrey L. Denburg
Keyword(s):  
Plasma Membrane ◽  
Membrane Effects

scholarly journals Dimerization of the Trk receptors in the plasma membrane: effects of their cognate ligands

2018 ◽  
Vol 475 (22) ◽  
pp. 3669-3685 ◽  
Author(s):  
Fozia Ahmed ◽  
Kalina Hristova
Keyword(s):  
Plasma Membrane ◽  
Ligand Binding ◽  
Conformational Changes ◽  
Tyrosine Kinases ◽  
Structural Changes ◽  
Control Cell ◽  
Trk Receptors ◽  
Surface Receptors ◽  
Neuronal Tissues ◽  
Membrane Effects

Receptor tyrosine kinases (RTKs) are cell surface receptors which control cell growth and differentiation, and play important roles in tumorigenesis. Despite decades of RTK research, the mechanism of RTK activation in response to their ligands is still under debate. Here, we investigate the interactions that control the activation of the tropomyosin receptor kinase (Trk) family of RTKs in the plasma membrane, using a FRET-based methodology. The Trk receptors are expressed in neuronal tissues, and guide the development of the central and peripheral nervous systems during development. We quantify the dimerization of human Trk-A, Trk-B, and Trk-C in the absence and presence of their cognate ligands: human β-nerve growth factor, human brain-derived neurotrophic factor, and human neurotrophin-3, respectively. We also assess conformational changes in the Trk dimers upon ligand binding. Our data support a model of Trk activation in which (1) Trks have a propensity to interact laterally and to form dimers even in the absence of ligand, (2) different Trk unliganded dimers have different stabilities, (3) ligand binding leads to Trk dimer stabilization, and (4) ligand binding induces structural changes in the Trk dimers which propagate to their transmembrane and intracellular domains. This model, which we call the ‘transition model of RTK activation,’ may hold true for many other RTKs.

Structure and Polarity of Mouse Brain Synaptic Plasma Membrane: Effects of Ethanol in vitro and in vivo

Biochemistry ◽  
1995 ◽  
Vol 34 (17) ◽  
pp. 5945-5959 ◽  
Author(s):  
Scott Colles ◽  
W. Gibson Wood ◽  
Sean Meyers-Payne ◽  
Jim Joseph ◽  
Friedhelm Schroeder
Keyword(s):  
Plasma Membrane ◽  
Mouse Brain ◽  
Synaptic Plasma Membrane ◽  
Membrane Effects

Plasma membrane effects of salicyclic acid treatment on cultured rose cells

1993 ◽  
Vol 33 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Terence M. Murphy ◽  
Ilya Raskin ◽  
Alexander J. Enyedi
Keyword(s):  
Plasma Membrane ◽  
Acid Treatment ◽  
Salicyclic Acid ◽  
Membrane Effects

scholarly journals The plasma membrane of Leishmania donovani promastigotes is the main target for CA(1–8)M(1–18), a synthetic cecropin A–melittin hybrid peptide

1998 ◽  
Vol 330 (1) ◽  
pp. 453-460 ◽  
Author(s):  
Pilar DÍAZ-ACHIRICA ◽  
Josep UBACH ◽  
Almudena GUINEA ◽  
David ANDREU ◽  
Luis RIVAS
Keyword(s):  
Plasma Membrane ◽  
Leishmania Donovani ◽  
Hybrid Peptide ◽  
Fast Kinetics ◽  
Micromolar Concentration ◽  
Cecropin A ◽  
Main Target ◽  
Membrane Effects ◽  
Leishmania Promastigotes ◽  
Kinetics Of

Reports on the lethal activity of animal antibiotic peptides have largely focused on bacterial rather than eukaryotic targets. In these, involvement of internal organelles as well as mechanisms different from those of prokaryotic cells have been described. CA(1-8)M(1-18) is a synthetic cecropin A-melittin hybrid peptide with leishmanicidal activity. Using Leishmania donovani promastigotes as a model system we have studied the mechanism of action of CA(1-8)M(1-18), its two parental peptides and two analogues. At micromolar concentration CA(1-8)M(1-18) induces a fast permeability to H+/OH-, collapse of membrane potential and morphological damage to the plasma membrane. Effects on other organelles are related to the loss of internal homeostasis of the parasite rather than to a direct effect of the peptide. Despite the fast kinetics of the process, the parasite is able to deactivate in part the effect of the peptide, as shown by the higher activity of the d-enantiomer of CA(1-8)M(1-18). Electrostatic interaction between the peptide and the promastigote membrane, the first event in the lethal sequence, is inhibited by polyanionic polysaccharides, including its own lipophosphoglycan. Thus, in common with bacteria, the action of CA(1-8)M(1-18) on Leishmania promastigotes has the same plasma membrane as target, but is unique in that different peptides show patterns of activity that resemble those observed on eukaryotic cells.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

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