1be8
From Proteopedia
(New page: 200px<br /><applet load="1be8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1be8, resolution 2.2Å" /> '''TRANS-CINNAMOYL-SUBTI...) |
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| - | [[Image:1be8.gif|left|200px]]<br /><applet load="1be8" size=" | + | [[Image:1be8.gif|left|200px]]<br /><applet load="1be8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1be8, resolution 2.2Å" /> | caption="1be8, resolution 2.2Å" /> | ||
'''TRANS-CINNAMOYL-SUBTILISIN IN WATER'''<br /> | '''TRANS-CINNAMOYL-SUBTILISIN IN WATER'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The x-ray crystal structures of trans-cinnamoyl-subtilisin, an acyl-enzyme | + | The x-ray crystal structures of trans-cinnamoyl-subtilisin, an acyl-enzyme covalent intermediate of the serine protease subtilisin Carlsberg, have been determined to 2.2-A resolution in anhydrous acetonitrile and in water. The cinnamoyl-subtilisin structures are virtually identical in the two solvents. In addition, their enzyme portions are nearly indistinguishable from previously determined structures of the free enzyme in acetonitrile and in water; thus, acylation in either aqueous or nonaqueous solvent causes no appreciable conformational changes. However, the locations of bound solvent molecules in the active site of the acyl- and free enzyme forms in acetonitrile and in water are distinct. Such differences in the active site solvation may contribute to the observed variations in enzymatic activities. On prolonged exposure to organic solvent or removal of interstitial solvent from the crystal lattice, the channels within enzyme crystals are shown to collapse, leading to a drop in the number of active sites accessible to the substrate. The mechanistic and preparative implications of our findings for enzymatic catalysis in organic solvents are discussed. |
==About this Structure== | ==About this Structure== | ||
| - | 1BE8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] with CA and TCA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Subtilisin Subtilisin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.62 3.4.21.62] Full crystallographic information is available from [http:// | + | 1BE8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=TCA:'>TCA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Subtilisin Subtilisin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.62 3.4.21.62] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BE8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Subtilisin]] | [[Category: Subtilisin]] | ||
| - | [[Category: Klibanov, A | + | [[Category: Klibanov, A M.]] |
| - | [[Category: Schmitke, J | + | [[Category: Schmitke, J L.]] |
| - | [[Category: Stern, L | + | [[Category: Stern, L J.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: TCA]] | [[Category: TCA]] | ||
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[[Category: serine protease]] | [[Category: serine protease]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:54:25 2008'' |
Revision as of 09:54, 21 February 2008
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TRANS-CINNAMOYL-SUBTILISIN IN WATER
Overview
The x-ray crystal structures of trans-cinnamoyl-subtilisin, an acyl-enzyme covalent intermediate of the serine protease subtilisin Carlsberg, have been determined to 2.2-A resolution in anhydrous acetonitrile and in water. The cinnamoyl-subtilisin structures are virtually identical in the two solvents. In addition, their enzyme portions are nearly indistinguishable from previously determined structures of the free enzyme in acetonitrile and in water; thus, acylation in either aqueous or nonaqueous solvent causes no appreciable conformational changes. However, the locations of bound solvent molecules in the active site of the acyl- and free enzyme forms in acetonitrile and in water are distinct. Such differences in the active site solvation may contribute to the observed variations in enzymatic activities. On prolonged exposure to organic solvent or removal of interstitial solvent from the crystal lattice, the channels within enzyme crystals are shown to collapse, leading to a drop in the number of active sites accessible to the substrate. The mechanistic and preparative implications of our findings for enzymatic catalysis in organic solvents are discussed.
About this Structure
1BE8 is a Single protein structure of sequence from Bacillus licheniformis with and as ligands. Active as Subtilisin, with EC number 3.4.21.62 Full crystallographic information is available from OCA.
Reference
Comparison of x-ray crystal structures of an acyl-enzyme intermediate of subtilisin Carlsberg formed in anhydrous acetonitrile and in water., Schmitke JL, Stern LJ, Klibanov AM, Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):12918-23. PMID:9789015
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