|
|
| Line 1: |
Line 1: |
| [[Image:1gzx.gif|left|200px]] | | {{Seed}} |
| | [[Image:1gzx.png|left|200px]] |
|
| |
|
| <!-- | | <!-- |
| Line 9: |
Line 10: |
| {{STRUCTURE_1gzx| PDB=1gzx | SCENE= }} | | {{STRUCTURE_1gzx| PDB=1gzx | SCENE= }} |
|
| |
|
| '''OXY T STATE HAEMOGLOBIN: OXYGEN BOUND AT ALL FOUR HAEMS'''
| | ===OXY T STATE HAEMOGLOBIN: OXYGEN BOUND AT ALL FOUR HAEMS=== |
|
| |
|
|
| |
|
| ==Overview==
| | <!-- |
| The cooperative binding of oxygen by haemoglobin results from restraints on ligand binding in the T state. The unfavourable interactions made by the ligands at the haems destabilise the T state and favour the high affinity R state. The T <==> R equilibrium leads, in the presence of a ligand, to a rapid increase in the R state population and therefore generates cooperative binding. There is now considerable understanding of this phenomenon, but the interactions that reduce ligand affinity in the T state have not yet been fully explored, owing to the difficulties in preparing T state haemoglobin crystals in which all the subunits are oxygenated. A protocol has been developed to oxygenate deoxy T state adult human haemoglobin (HbA) crystals in air at 4 C at all four haems without significant loss of crystalline order. The X-ray crystal structure, determined to 2.1 A spacing, shows significant changes in the alpha and beta haem pockets as well as changes at the alpha(1)beta(2) interface in the direction of the R quaternary structure. Most of the shifts and deviations from deoxy T state HbA are similar to, but larger than, those previously observed in the T state met and other partially liganded T state forms. They provide clear evidence of haem-haem interaction in the T state. | | The line below this paragraph, {{ABSTRACT_PUBMED_8642597}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 8642597 is the PubMed ID number. |
| | --> |
| | {{ABSTRACT_PUBMED_8642597}} |
|
| |
|
| ==About this Structure== | | ==About this Structure== |
| Line 31: |
Line 35: |
| [[Category: Oxygen binding]] | | [[Category: Oxygen binding]] |
| [[Category: Transport]] | | [[Category: Transport]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 18:14:04 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 06:23:29 2008'' |