Sandbox Reserved 954: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 32: | Line 32: | ||
The inhibitory members of serpin family undergo an unusual conformational change, the Stressed to Relaxed transition. This structural transition causes the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> insertion into <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene> thereby the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> forms an extra β strand . The serpin conformational change is essential for the inhibition mechanism of proteases. <scene name='60/604473/Rcl_insertion_into_beta_sheet/1'>Some amino-acids of RCL</scene> wich belong to a consensus sequence for inhibitory serpins are thought to permit the insertion of the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> into the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene>.<ref> James C Whisstocka, 2, Richard Skinnera, 2, Robin W Carrella, Arthur M Leska, Conformational changes in serpins: I. the native and cleaved conformations of α1-antitrypsin1, http://www.sciencedirect.com/science/article/pii/S0022283699935209 DOI:pii/S0022283699935209</ref> | The inhibitory members of serpin family undergo an unusual conformational change, the Stressed to Relaxed transition. This structural transition causes the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> insertion into <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene> thereby the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> forms an extra β strand . The serpin conformational change is essential for the inhibition mechanism of proteases. <scene name='60/604473/Rcl_insertion_into_beta_sheet/1'>Some amino-acids of RCL</scene> wich belong to a consensus sequence for inhibitory serpins are thought to permit the insertion of the <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> into the <scene name='60/604473/A_beta_sheet/3'>A β-sheet</scene>.<ref> James C Whisstocka, 2, Richard Skinnera, 2, Robin W Carrella, Arthur M Leska, Conformational changes in serpins: I. the native and cleaved conformations of α1-antitrypsin1, http://www.sciencedirect.com/science/article/pii/S0022283699935209 DOI:pii/S0022283699935209</ref> | ||
[[Image:Structure region.jpg|thumbnail|300px | [[Image:Structure region.jpg|thumbnail|300px]] | ||
==Function== | ==Function== | ||
| Line 49: | Line 49: | ||
Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australiahttp://onlinelibrary.wiley.com/doi/10.1111/j.1399-0039.2008.01059.x/pdf DOI : 10.1111/j.1399-0039.2008.01059.x/pdf </ref> http://genome.cshlp.org/content/10/12/1845 | Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australiahttp://onlinelibrary.wiley.com/doi/10.1111/j.1399-0039.2008.01059.x/pdf DOI : 10.1111/j.1399-0039.2008.01059.x/pdf </ref> http://genome.cshlp.org/content/10/12/1845 | ||
[[Image: | [[Image:fonction1.jpg|thumbnail|900px]] | ||
Before the hydrolysis of the acyl-enzyme intermediate, the serpin rapidly undergoes from Stressed to Relaxed transition. The <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> remains covalently attached to the protease, however the protease is moved from the top to the bottom of SCCA1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0104935 | Before the hydrolysis of the acyl-enzyme intermediate, the serpin rapidly undergoes from Stressed to Relaxed transition. The <scene name='60/604473/The_rcl_loop_scene/3'>RCL</scene> remains covalently attached to the protease, however the protease is moved from the top to the bottom of SCCA1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0104935 | ||
This move induce a protease distortion into a conformation, in which the acyl enzyme intermediate is hydrolysed extremely slowly. The active site of the enzyme would be expected to break.The protease thus remains covalently attached to the target protease and is thereby inhibited. | This move induce a protease distortion into a conformation, in which the acyl enzyme intermediate is hydrolysed extremely slowly. The active site of the enzyme would be expected to break.The protease thus remains covalently attached to the target protease and is thereby inhibited. | ||
Consequently, the serpin has to be cleaved to inhibit the target protases. Thus, SCCA1 is irreversible protease inhibitor. | Consequently, the serpin has to be cleaved to inhibit the target protases. Thus, SCCA1 is irreversible protease inhibitor. | ||
