Odorant binding protein: Difference between revisions

This model is supported by the pH dependent conformation transition, that is described above. The bulk of the sensillar lymph is in neutral pH (6.5-7), while environment near the dendrite membrane bears a low pH (4.5), due to the negative charges on the surface of the membrane <ref>DOI: 10.1016/0040-8166(84)90004-1</ref>, which cause the accumulation of positively charged kations near the membrane surface (20-50 nm)<ref name="kaissling" /><ref>. According to this model, the pheromone is entering the sensillar lymph through a pore in the cuticle, then it can be either degraded by odorant degrading enzymes (ODE) or bind to a PBP (of both forms). Once the complex is arriving to the low pH environment near the dendrite membrane the PBP will shift to the A-form, thereby ejaculating the ligand from the binding pocket, allowing it to activate the OR:CO-OR complex and the cellular signal transduction begins.       

   

*'''Activation by the complex pheromone-PBP'''

An alternative mode of action was proposed for the receptor activation in ''Drosophila melanogaster'', where it was found that the complex of pheromone-PBP is required for the activity of pheromone-sensitive neurons <ref>DOI: 10.1016/j.neuron.2004.12.031<ref/><ref>doi: 10.1016/j.cell.2008.04.046<ref/>