Odorant binding protein: Difference between revisions

Line 44:

====Protein conformations====

[[Image:A -B forms without ligand.png|thumb|upright=2|The A and B forms without ligand (PDB IDs: [[1gm0]] and [[1ls8]]).]]

BmorPBP has two conformations: The "~~open~~ form" (A) and the "~~close~~ form" (B)<ref>DOI: 10.1074/jbc.274.43.30950</ref>. The bombykol and the alpha-helix loacated in the c-terminus of the protein compete for the binding site: when the c-terminus is inside the binding cavity it get's an alpha helix shape, and the protien is in its "close form" (B), whereas in the "open form" (A) the c-terminus is outside of the protein and has no defined secondary structure. Binding experiments have shown that the B-form binds 15 times higher than the A-form <ref>doi: 10.1073/pnas.0501447102</ref>, therefore considered to be the carrier of the pheromone. The complex of the A-form and the pheromone, is then considered the form that activates the receptor.

BmorPBP has two conformations: The "closed form" (A) and the "open form" (B)<ref>DOI: 10.1074/jbc.274.43.30950</ref>. The bombykol and the alpha-helix loacated in the c-terminus of the protein compete for the binding site: when the c-terminus is inside the binding cavity it get's an alpha helix shape, and the protien is in its "close form" (B), whereas in the "open form" (A) the c-terminus is outside of the protein and has no defined secondary structure. Binding experiments have shown that the B-form binds 15 times higher than the A-form <ref>doi: 10.1073/pnas.0501447102</ref>, therefore considered to be the carrier of the pheromone. The complex of the A-form and the pheromone, is then considered the form that activates the receptor.

The <scene name='68/683383/1dqe-1gm0/2'>transition between the two conformation</scene> is both pH and ligand dependent <ref>doi: 10.1073?pnas.251532998</ref><ref>DOI: 10.1016/j.bbrc.2005.07.176</ref><ref>doi: 10.1073/pnas.1317706110</ref>. In short, the B-form (c-terminus outside the cavity) occurs only at neutral pH and in the presence of the ligand. The A-form (c-terminus inside the cavity) occurs at both low and neutral pH, yet at the latter only in the absence of ligand. Therefore, in neutral pH when the ligand is binding to the protein in its A-form, the complex formation causes a change in conformation to the B-form. However, both A and B forms are equally distributed in the lymph.

Odorant binding protein: Difference between revisions

Navigation menu

Page actions

Page actions

Personal tools

Navigation

Search

Tools

@@ Line 44: / Line 44: @@
 ====Protein conformations====
 [[Image:A -B forms without ligand.png|thumb|upright=2|The A and B forms without ligand (PDB IDs: [[1gm0]] and [[1ls8]]).]]
-BmorPBP has two conformations: The "open form" (A) and the "close form" (B)<ref>DOI: 10.1074/jbc.274.43.30950</ref>. The bombykol and the alpha-helix loacated in the c-terminus of the protein compete for the binding site: when the c-terminus is inside the binding cavity it get's an alpha helix shape, and the protien is in its "close form" (B), whereas in the "open form" (A) the c-terminus is outside of the protein and has no defined secondary structure. Binding experiments have shown that the B-form binds 15 times higher than the A-form <ref>doi: 10.1073/pnas.0501447102</ref>, therefore considered to be the carrier of the pheromone. The complex of the A-form and the pheromone, is then considered the form that activates the receptor.
+BmorPBP has two conformations: The "closed form" (A) and the "open form" (B)<ref>DOI: 10.1074/jbc.274.43.30950</ref>. The bombykol and the alpha-helix loacated in the c-terminus of the protein compete for the binding site: when the c-terminus is inside the binding cavity it get's an alpha helix shape, and the protien is in its "close form" (B), whereas in the "open form" (A) the c-terminus is outside of the protein and has no defined secondary structure. Binding experiments have shown that the B-form binds 15 times higher than the A-form <ref>doi: 10.1073/pnas.0501447102</ref>, therefore considered to be the carrier of the pheromone. The complex of the A-form and the pheromone, is then considered the form that activates the receptor.
 The <scene name='68/683383/1dqe-1gm0/2'>transition between the two conformation</scene> is both pH and ligand dependent <ref>doi: 10.1073?pnas.251532998</ref><ref>DOI: 10.1016/j.bbrc.2005.07.176</ref><ref>doi: 10.1073/pnas.1317706110</ref>. In short, the B-form (c-terminus outside the cavity) occurs only at neutral pH and in the presence of the ligand. The A-form (c-terminus inside the cavity) occurs at both low and neutral pH, yet at the latter only in the absence of ligand. Therefore, in neutral pH when the ligand is binding to the protein in its A-form, the complex formation causes a change in conformation to the B-form. However, both A and B forms are equally distributed in the lymph.