Interactions of membranes

M. le Maire, P. Champed, J. V. Moller (2000) Interaction of membrane proteins and lipids with solubilizing detergents. Biochim. Biophys. Acta, 1508 86-111... 

R. Kramer, Interaction of membrane surface charges with the reconstituted ADP/ATP-carrier from mitochondria, Biochim. Biophys. Acta 735, 145-159 (1983). 

B lymphocytes may be activated by a cell-cell interaction with T lymphocytes, i.e., they are stimulated to proliferate and produce antibodies. Stimulation of B lymphocytes takes place in a complex with T lymphocytes and this complex formation is mediated by a number of protein-protein interactions of membrane proteins from both cell types. The proteins involved are receptor systems with corresponding hgands on the partner cell. Tlie hgands are either secreted proteins or membrane proteins that speci-ficaUy bind to receptors on the surface of the partner cell, which in this case is a B or T lymphocyte. 

Lipids and proteins can diffuse laterally within the plane of the membrane, but this mobility is limited by interactions of membrane proteins with internal cytoskeletal structures and interactions of lipids with lipid rafts. One class of lipid rafts consists of sphingolipids and cholesterol with a subset of membrane proteins that are GPI-linked or attached to several long-chain fatty acyl moieties. 

Kaczmarek, L. K. Cation binding models for the interaction of membranes with EM fields. Neurosci. Res. Program Bull. 1977, 15, 54-60. 

Fig. 3.5 Model of cell activation initiated by LBP. Dual role of the LPS-binding protein LBP On the one hand, LBP mediates and enhances the activation of immune cells induced by LPS. This process seems to be influenced by LBP which is intercalated in or associated with the immune cell membrane (upper cartoon). An interaction of membrane-bound LBP (mLBP) with LPS can led to an intercalation of LPS into the phospholipid matrix. On the other hand, the interaction between soluble LBP (sLBP) and LPS aggregates induces a multilamellarization of the aggregates and finally to a neutralization of the endotoxin because of the inhibition of the binding to signaling proteins of the immune cell (lower cartoon)...

O Brien, J.E, E. Dahlhoff, and G.N. Somero (1991). Thermal resistance of mitochondrial respiration hydrophobic interactions of membrane proteins may limit mitochondrial thermal resistance. Physiol. Zool. 64 1509-1526. 

Mekler, V.M. and Umarova, F.T. (1988) The use of triplet-sensitized photochromism phenomenon for the study of dynamic interaction of membrane proteins, Biofizika 33, 720-722. 

T-cell activation involves interactions of membrane-bound immunoglobulin-like receptors with membranous antigen-MHC complexes. The antigen receptors of B and T lymphocytes are complex membrane-bound multisubunit proteins. Antigen receptors are immunoglobulin (Ig)-like antibody molecules. B cells do not secrete the first antibodies that they make, instead, they insert them into the plasma membrane, where they now serve as receptors for antigen. Each B cell has approximately 10 such molecules in the plasma membrane. 

Membrane proteins are difficult to work with. Solubilization in a semi-fiinctional form is possible with the aid of certain non-ionic detergents (3) the sheath of detergent molecules attached to the hydrophobic regions of these molecules compromise studies of interactions of membrane proteins. Thus, a method applicable to an intact cell or organelle may have some value. The system here involves membrane proteins (PBPs) and cytosolic proteins (most of the other MGPs) and thus demonstrates that such proteins and their interacting ligands can be accessed. 

Assessing Forces that Determine Stability and Interactions of Membrane Proteins... 

Figure 18.1 Models for different modes of peptide-lipid interaction of membrane-active peptides. The peptide remains unstructured in solution and acquires an amphipathic structure in the presence of a membrane. The hydrophobic face of the amphipathic peptide binds to the membrane, as represented by the grayscale. At low concentration, the peptide lies on the surface. At higher peptide concentrations the membrane becomes disrupted, either by the formation of transmembrane pores or by destabilization via the "carpet mechanism." In the "barrel-stave pore" the pore consists of peptides alone, whereas in the "toroidal wormhole pore" negatively charged lipids also line the pore, counteracting the electrostatic repulsion between the positively charged peptides. The peptide may also act as a detergent and break up the membrane to form small aggregates. Peptides can also induce inverted micelle structures in the membrane.

Tsong, T. Y. Chauvin, F. Astumian, R. D. Interaction of membrane proteins with static and dynamic electric fields via electroconformational coupling. In Mechanistic Approaches to Interaction of Electromagnetic Fields with Living Systems Blank, M. Findl, E., Eds. Plenum New York pp 187-202. 

Im, W., Feig, M., Brooks 111, C.L. An implicit membrane Generalized Bom theory for the study of structure, stability, and interactions of membrane proteins. Biophys. J. 2003,85,2900-18. 

S. Marcelja, Toward a realistic theory of the interaction of membrane inclusions, Biophys. J., 1999, 76, 593-594. 

Determination of the coefficients based on understanding of the membrane microstructure and modelling of the interaction between the membrane and the two transported species, i.e. hydronium and water, would be better. Most desirable would be a proper mathematical transition from an exact microscopic description of the interaction of membrane, hydronium and water, towards a macroscopic model. Such information and description being currently unavailable, we have to rely on guidance from knowledge on the membrane morphology to devise assumptions on the functional dependence of the coefficients on temperature and water content. 

These reports indicated that importance of IR spectroscopy in analysis of chemical structures of membranes and interactions of membranes with other materials. Accordingly, IR analysis could provide to verify the chemical structure of ESA membranes. 

Lipids are a diverse group of biomolecules that are known to exist as thousands of distinct covalent entities, each with its nniqne stmctnral and physical characteristics. Lipids are essential cellular constituents that have multiple distinct roles in cellular functions. They participate in the storage of energy, cell-ceU communication, cell-cell recognition, and various human diseases. They provide a barrier that separates intracellular and extracellular compartments and a matrix for the interactions of membrane-bound proteins. 

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