Sandbox Reserved 1105: Difference between revisions
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==== TTR-T4 complex ==== | ==== TTR-T4 complex ==== | ||
The crystal structure of this complex is orthorhombic <ref name="wo">Wojtczak, A., Cody, V., Luft, J. R., & Pangborn, W. (1996). Structures of Human Transthyretin Complexed with Thyroxine at 2.0 Å Resolution and 3’,5’-Dinitro-N-acetyl-L-thyronine at 2.2 Å Resolution. Acta Crystallographica Section D Biological Crystallography, 52(4), 758–765. doi:http://dx.doi.org/ 10.1107/s0907444996003046 </ref>. | The crystal structure of this complex is orthorhombic <ref name="wo">Wojtczak, A., Cody, V., Luft, J. R., & Pangborn, W. (1996). Structures of Human Transthyretin Complexed with Thyroxine at 2.0 Å Resolution and 3’,5’-Dinitro-N-acetyl-L-thyronine at 2.2 Å Resolution. Acta Crystallographica Section D Biological Crystallography, 52(4), 758–765. doi:http://dx.doi.org/10.1107/s0907444996003046 </ref>. | ||
Two hormone binding sites are located at the dimer–dimer region bind T4 with negative cooperativity. Under physiological conditions, the bound between the natural ligand and the tetramer can’t be broken down. Moreover, there is only one hormone bound per tetramer. The negative cooperativity mechanism explain the fact that the affinity constants (Ka) for the binding of the first and the second T4 changes, they are respectively 108 and 106 M-1 <ref name= "Klabunde">PMID: 10742177</ref>. | Two hormone binding sites are located at the dimer–dimer region bind T4 with negative cooperativity. Under physiological conditions, the bound between the natural ligand and the tetramer can’t be broken down. Moreover, there is only one hormone bound per tetramer. The negative cooperativity mechanism explain the fact that the affinity constants (Ka) for the binding of the first and the second T4 changes, they are respectively 108 and 106 M-1 <ref name= "Klabunde">PMID: 10742177</ref>. | ||
[[Image:t4.png|thumb|left|alt=Puzzle globe|Caption for the image|Structure of thyroxine (T4)|200px]] | [[Image:t4.png|thumb|left|alt=Puzzle globe|Caption for the image|Structure of thyroxine (T4)|200px]] | ||