Corticosteroid-binding globulin: Difference between revisions
From Proteopedia
Jump to navigationJump to search
Michal Harel (talk | contribs) No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
< | <StructureSection load='2V95' size='450' side='right' scene='' caption='Cartoon representation of corticosteroid-binding globulin complex with cortisol, [[2v95]]'> | ||
[[Image:2v95.png|left|200px|thumb|Crystal Structure of corticosteroid-binding globulin complex with cortisol, [[2v95]]]] | [[Image:2v95.png|left|200px|thumb|Crystal Structure of corticosteroid-binding globulin complex with cortisol, [[2v95]]]] | ||
==Introduction== | ==Introduction== | ||
| Line 19: | Line 15: | ||
Previously-solved structures of the human CBG-antitrypsin (Pittsburgh) chimera with cleaved reactive centre loop at 1.84Å and the native rat CBG at 1.9Å confirm that corticosteroid-binding globulin, despite being a non-inhibitory member of the serpin family, undergoes the S-to-R transition just like the inhibitory members <ref>PMID:17644521 </ref>,<ref>PMID:18513745 </ref>. | Previously-solved structures of the human CBG-antitrypsin (Pittsburgh) chimera with cleaved reactive centre loop at 1.84Å and the native rat CBG at 1.9Å confirm that corticosteroid-binding globulin, despite being a non-inhibitory member of the serpin family, undergoes the S-to-R transition just like the inhibitory members <ref>PMID:17644521 </ref>,<ref>PMID:18513745 </ref>. | ||
In its native form, CBG is in the "stressed" conformation and binds cortisol with very high affinity<ref>PMID:17644521 </ref>. | In its native form, CBG is in the "stressed" conformation and binds cortisol with very high affinity<ref>PMID:17644521 </ref>. | ||
Upon cleavage by its target proteinase, believed to be human neutrophil elastase, the protein undergoes structural rearrangements in the main chain at several parts of the serpin fold, resulting in what is conventionally known as the "relaxed" state <ref>PMID:18513745 </ref>,<ref>PMID:3143075 </ref>, as seen <scene name='Corticosteroid-binding_globulin/Cleaved/9'>here</scene>. The main conformational change is the insertion of the entire N-terminal segment of the reactive loop into beta-sheet A where it is incorporated as a <scene name='Corticosteroid-binding_globulin/Cleaved/10'>novel beta-strand</scene>. | |||
''(Click'' <scene name='Corticosteroid-binding_globulin/Native/1'>here</scene> ''to return to structure of CBG in the S-state.) | ''(Click'' <scene name='Corticosteroid-binding_globulin/Native/1'>here</scene> ''to return to structure of CBG in the S-state.) | ||
