Pheromone binding conformational change

Figure 12.7 Effector mechanism opening or dosing of an ion channel. The binding of the hormone opens an ion channel. The link between the receptor and the ion channel may be via a messenger molecule that causes a conformational change in one of the proteins in the channel or may be via phosphorylation of one of the proteins in the channel. An example of opening an ion channel is that of a pheromone on a sensory cell in the olfaction epithelium (see below).

Wojtasek H. and Leal W. S. (1999) Conformational change in the pheromone-binding protein from Bombyx mori induced by pH and by interaction with membranes. J. Biol. Chem. 274, 30950-30956. 

Figure 15.8 Schematic representation of the proposed mechanisms for mode of action of OBPs in the perireceptor events. Pheromone (or other semiochemicals) enters the sensillar lymph through cuticular openings (pore tubules), is solubilized by an odorant-binding protein, transported to the olfactory receptors, and protected from degrading enzymes. Interaction with negatively charged sites at the surface of the dendrites triggers a conformational change that leads to the formation of a C-terminal a-helix. The insertion of this helix into the binding cavity ejects the pheromone to the olfactory receptors.

Mohl C., Breer H. and Krieger J. (2002) Species-specific pheromonal compounds induce distinct conformational changes of pheromone binding protein subtypes from Antheraea polyphemus. Invert. Neurosci. 4, 165-174. 

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