2bdb: Difference between revisions

Revision as of 17:36, 21 February 2008

Porcine pancreatic elastase complexed with Asn-Pro-Ile and Ala-Ala at pH 5.0

OverviewOverview

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 StructureAbout this Structure

2BDB 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.

ReferenceReference

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 16:36:32 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:2bdb.gif|left|200px]]<br /><applet load="2bdb" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2bdb.gif|left|200px]]<br /><applet load="2bdb" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2bdb, resolution 1.700&Aring;" />
 '''Porcine pancreatic elastase complexed with Asn-Pro-Ile and Ala-Ala at pH 5.0'''<br />
 ==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.
+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==
-BDB 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 and ALA 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BDB OCA].
+BDB 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> and <scene name='pdbligand=ALA:'>ALA</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=2BDB OCA].
 ==Reference==
@@ Line 15: / Line 15: @@
 [[Category: Sus scrofa]]
 [[Category: Liu, B.]]
-[[Category: Schofield, C.J.]]
+[[Category: Schofield, C J.]]
-[[Category: Wilmouth, R.C.]]
+[[Category: Wilmouth, R C.]]
 [[Category: ALA]]
 [[Category: CA]]
@@ Line 22: / Line 22: @@
 [[Category: serine proteinase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 08:44:41 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:36:32 2008''