Membrane proteins, activation

The objective of this study was also to establish a link between an easily observable allelopathic effect (growth inhibition of roots) and a cellular-based explanation (membrane permeability changes). Several modes of action can explain these results, such as an increase in the lipid peroxidation, a disruption in the intrinsic membrane protein activities, or an alteration in plasma membrane ATPase activity. 

Tetracycline Binds to the 30S ribosomal subunit and prevents the tRNA from interacting with the ribosome A membrane protein actively expels or transports the antibiotic out of the cell... 

Gruner SM. Coupling between bilayer curvature elasticity and membrane-protein activity. In Biomembrane Electrochemistry, Volume 235. Blank M, Vodyanoy I, eds. 1994. American Chemical Society, Washington, DC. pp. 129-149. 

The lipid bilayer is not passive in determining membrane protein activity and function, and an accumulating body of evidence indicates that there is a coupling of membrane proteins to lipid bilayer properties. These properties include the effect of bilayer curvature strain (20), the role of specific lipids such as phosphoinositides, (21) and the effect of thickness on membrane protein function (22). The lipid composition, as well as the bilayer properties that result from this composition, act as allosteric regulators of membrane protein function. 

Coupling between Bilayer Curvature Elasticity and Membrane Protein Activity... 

The binding sites for lipopolysaccharides on mouse lymphocytes have been identified as membrane proteins. Active fractions isolated by affinity chromatography from B cell membranes were identified as immunoglobulins, possibly IgM and IgD, whilst the histocompatibility-2 complex proteins (H-2D, H-2K, and la antigens) were found to be binding sites for lipopolysaccharides on both B and T cells. 

Further biological modifications are possible by adding natural lipids or membrane proteins (such as ATPase) to polymerizable membranes. Membrane protein activity can be retained after polymerization. The natural, non-polymerizable lipid component can be selectively degraded (for instance by phospholipase A2) to open up the previously stable compartment. The pol3mierization behaviour of... 

Carruthers, A. and Melchior, D.L. (1986) How bilayer lipids affect membrane protein activity. Trends Biochem. ScL, 11, 331-335. 

---