2bd8
From Proteopedia
(New page: 200px<br /><applet load="2bd8" size="450" color="white" frame="true" align="right" spinBox="true" caption="2bd8, resolution 1.700Å" /> '''Porcine pancreatic ...) |
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| - | [[Image:2bd8.gif|left|200px]]<br /><applet load="2bd8" size=" | + | [[Image:2bd8.gif|left|200px]]<br /><applet load="2bd8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2bd8, resolution 1.700Å" /> | caption="2bd8, resolution 1.700Å" /> | ||
'''Porcine pancreatic elastase complexed with beta-casomorphin-7 and Arg-Phe at pH 5.0 (50 min soak) and immersed in pH 9 buffer for 30 seconds'''<br /> | '''Porcine pancreatic elastase complexed with beta-casomorphin-7 and Arg-Phe at pH 5.0 (50 min soak) and immersed in pH 9 buffer for 30 seconds'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Mass spectrometric screening reveals that an unmodified natural | + | Mass spectrometric screening reveals that an unmodified natural heptapeptide--human beta-casomorphin-7, an internal sequence of human beta-casein that possesses opioid-like activity--reacts with porcine pancreatic elastase to form an unusually stable acyl-enzyme complex at low pH. X-ray crystallographic analysis (to 1.9 A resolution) at pH 5 shows continuous electron density linking the C-terminal isoleucine of beta-casomorphin-7 to Ser 195 through an ester bond. The structure reveals a well defined water molecule (Wat 317), equidistant between the carbon of the ester carbonyl and N epsilon 2 of His 57. Deprotonation of Wat 317 will produce a hydroxide ion positioned to attack the ester carbonyl through the favoured Burgi-Dunitz trajectory. |
==About this Structure== | ==About this Structure== | ||
| - | 2BD8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with CA, SO4, ARG and PHE as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pancreatic_elastase Pancreatic elastase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.36 3.4.21.36] Full crystallographic information is available from [http:// | + | 2BD8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=ARG:'>ARG</scene> and <scene name='pdbligand=PHE:'>PHE</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pancreatic_elastase Pancreatic elastase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.36 3.4.21.36] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BD8 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Sus scrofa]] | [[Category: Sus scrofa]] | ||
[[Category: Liu, B.]] | [[Category: Liu, B.]] | ||
| - | [[Category: Schofield, C | + | [[Category: Schofield, C J.]] |
| - | [[Category: Wilmouth, R | + | [[Category: Wilmouth, R C.]] |
[[Category: ARG]] | [[Category: ARG]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: serine proteinase]] | [[Category: serine proteinase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:36:34 2008'' |
Revision as of 14:36, 21 February 2008
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Porcine pancreatic elastase complexed with beta-casomorphin-7 and Arg-Phe at pH 5.0 (50 min soak) and immersed in pH 9 buffer for 30 seconds
Overview
Mass spectrometric screening reveals that an unmodified natural heptapeptide--human beta-casomorphin-7, an internal sequence of human beta-casein that possesses opioid-like activity--reacts with porcine pancreatic elastase to form an unusually stable acyl-enzyme complex at low pH. X-ray crystallographic analysis (to 1.9 A resolution) at pH 5 shows continuous electron density linking the C-terminal isoleucine of beta-casomorphin-7 to Ser 195 through an ester bond. The structure reveals a well defined water molecule (Wat 317), equidistant between the carbon of the ester carbonyl and N epsilon 2 of His 57. Deprotonation of Wat 317 will produce a hydroxide ion positioned to attack the ester carbonyl through the favoured Burgi-Dunitz trajectory.
About this Structure
2BD8 is a Single protein structure of sequence from Sus scrofa with , , and as ligands. Active as Pancreatic elastase, with EC number 3.4.21.36 Full crystallographic information is available from OCA.
Reference
Structure of a specific acyl-enzyme complex formed between beta-casomorphin-7 and porcine pancreatic elastase., Wilmouth RC, Clifton IJ, Robinson CV, Roach PL, Aplin RT, Westwood NJ, Hajdu J, Schofield CJ, Nat Struct Biol. 1997 Jun;4(6):456-62. PMID:9187653
Page seeded by OCA on Thu Feb 21 16:36:34 2008
Categories: Pancreatic elastase | Single protein | Sus scrofa | Liu, B. | Schofield, C J. | Wilmouth, R C. | ARG | CA | PHE | SO4 | Serine proteinase
