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Odorant binding protein
From Proteopedia
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====Bombyx mori BmorPBP (lets talk about sex..)==== | ====Bombyx mori BmorPBP (lets talk about sex..)==== | ||
| - | [[Image:Bombykol.png|thumb|upright=1 | + | [[Image:Bombykol.png|thumb|upright=1|Bombykol, a sex pheromone of ''Bombyx mori'', from [http://pubchem.ncbi.nlm.nih.gov/compound/Bombykol#section=Top PubChem]]] |
==== BmorPBP Function ==== | ==== BmorPBP Function ==== | ||
| - | Despite three decades of intensive research, the exact roles of OBP and the mechanism by which the odorant receptor (OR) is activated are still in dispute | + | Despite three decades of intensive research, the exact roles of OBP and the mechanism by which the odorant receptor (OR) is activated are still in dispute <ref>DOI: 10.1146/annurev-ento-120811-153635</ref><ref>DOI: 10.1007/s00359-009-0461-4</ref>. |
| + | Of all, the role of OBP as an odorant carrier is generally accepted. | ||
'''A few functions have been suggested for OBP:''' | '''A few functions have been suggested for OBP:''' | ||
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3. | 3. | ||
4. | 4. | ||
| - | + | ||
| - | + | ||
<StructureSection load='1DQE' size='340' side='right' caption='''Bombyx mori'' PBP and his ligand - the moth pheromone [[bombykol]]' scene=''> | <StructureSection load='1DQE' size='340' side='right' caption='''Bombyx mori'' PBP and his ligand - the moth pheromone [[bombykol]]' scene=''> | ||
| - | + | <scene name='68/683383/1dqe-1gm0/2'>TextToBeDisplayed</scene> | |
| + | {{Button Toggle AnimationOnPause}} | ||
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======Receptor activation i lepidoptora====== | ======Receptor activation i lepidoptora====== | ||
| - | *'''The pH theory''' | + | *'''The pH dependent theory''' |
| - | This theory is supported by | + | This theory is supported by few assumptions. First, it has been found that the BmPBP conformation is changing from its [["open form" (A)]] to the [["close form" (B)]] in a pH dependent manner <ref>DOI: 10.1074/jbc.274.43.30950</ref>, and that the two conformations has different ligand affinities. |
| - | + | Second, the surface of the dendrite is negatively charged <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), thereby inducing a low pH environment near the dendrite membrane [[kaissling 2009]] | |
Revision as of 08:48, 8 January 2015
Contents |
Introduction
Odorant-binding protein (OBP) are soluble proteins which involve in the processes of odorant detection in the olfactory sensilla.
The first OBP that was identified is Bovine odorant binding protein, that was isolated from a cow's mucus ref. OBP in vertebrates
OBP in insects
In order to explain the structure and function of these fascinating proteins, this page will further focus on a particular OBP - the well investigated Bombyx mori PBP: BmorPBP.
PBP
PBPs are specialized members of the insect odorant-binding protein (OBP) super-family, and they are categorized into three groups by their lengths: the long-chain PBPs (∼160 aa), the medium-chain PBPs (∼120 aa), and the short-chain PBPs (∼110 aa)
Bombyx mori BmorPBP (lets talk about sex..)
BmorPBP Function
Despite three decades of intensive research, the exact roles of OBP and the mechanism by which the odorant receptor (OR) is activated are still in dispute [1][2]. Of all, the role of OBP as an odorant carrier is generally accepted.
A few functions have been suggested for OBP: 1. 2. 3. 4.
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Protein conformations
Receptor activation i lepidoptora
- The pH dependent theory
This theory is supported by few assumptions. First, it has been found that the BmPBP conformation is changing from its "open form" (A) to the "close form" (B) in a pH dependent manner [3], and that the two conformations has different ligand affinities.
Second, the surface of the dendrite is negatively charged [4], which cause the accumulation of positively charged kations near the membrane surface (20-50 nm), thereby inducing a low pH environment near the dendrite membrane kaissling 2009
Leal WS, et al. (2005) Kinetics and molecular properties of pheromone binding and release. Proc Natl Acad Sci USA 102(15):5386–5391.
- The other theory
See also
References
- ↑ Leal WS. Odorant reception in insects: roles of receptors, binding proteins, and degrading enzymes. Annu Rev Entomol. 2013;58:373-91. doi: 10.1146/annurev-ento-120811-153635. Epub, 2012 Sep 27. PMID:23020622 doi:http://dx.doi.org/10.1146/annurev-ento-120811-153635
- ↑ Kaissling KE. Olfactory perireceptor and receptor events in moths: a kinetic model revised. J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Oct;195(10):895-922. , doi: 10.1007/s00359-009-0461-4. Epub 2009 Aug 21. PMID:19697043 doi:http://dx.doi.org/10.1007/s00359-009-0461-4
- ↑ Hubert Wojtasek and Walter S. Leal. Conformational Change in the Pheromone-binding Protein fromBombyx mori Induced by pH and by Interaction with Membranes, 1999 The Journal of Biological Chemistry, 274, 30950-30956. doi:http://dx.doi.org/10.1074/jbc.274.43.30950
- ↑ Thomas A Keil, Surface coats of pore tubules and olfactory sensory dendrites of a silkmoth revealed by cationic markers, Tissue and Cell (1984), Vol 16, Issue 5, 705-717 doi:http://dx.doi.org/10.1016/0040-8166(84)90004-1
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