Biochemical effects interaction with specific protein receptors

BIOCHEMICAL EFFECTS INTERACTION WITH SPECIFIC PROTEIN RECEPTORS... 

Biochemical Effects Interactions with Specific Protein Receptors... 

Biochemical effects interaction with specific protein receptors 311... 

At a cellular level, the activation of mAChRs leads to a wide spectrum of biochemical and electrophysiological responses [1, 5]. The precise pattern of responses that can be observed does not only depend on the nature of the activated G proteins (receptor subtypes) but also on which specific components of different signaling cascades (e.g. effector enzymes or ion channels) are actually expressed in the studied cell type or tissue. The observed effects can be caused by direct interactions of the activated G protein(s) with effector enzymes or ion channels or may be mediated by second messengers (Ca2+, DP3, etc.) generated upon mAChR stimulation. 

Figure 10.1 Biochemical mechanism of action of PGE and PCF j receptors. PGE and are envisaged as interacting with receptors coupled to guanine nucleotide regulatory (N) proteins. Interactions of an agonist-occupied receptor with a trimeric N protein in the presence of GTP causes dissociation of the N protein into a and Py subunits. The results depend on the specific effects of the a and subunits in the target cell...

In the absence of electrostatic effects on adsorption and of specific biochemical interactions (e.g., receptor-ligand) as well, the first subequilibrium state should be effectively characterized by the work of adhesion between protein and surface. Absolom et al. [87] used a fundamentally similar approach to describe the adhesion of bacteria to various polymeric low energy surfaces with good success. The model proposed here is limited to adsorption at hydrophobic interfaces so from a thermodynamic standpoint, the surface energies of each of the interacting phases should adequately describe the initial adsorption event. 

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