1fq7: Difference between revisions

Revision as of 13:41, 21 February 2008

X-RAY STRUCTURE OF INHIBITOR CP-72,647 BOUND TO SACCHAROPEPSIN

OverviewOverview

Saccharopepsin is a vacuolar aspartic proteinase involved in activation of a number of hydrolases. The enzyme has great structural homology to mammalian aspartic proteinases including human renin and we have used it as a model system to study the binding of renin inhibitors by X-ray crystallography. Five medium-to-high resolution structures of saccharopepsin complexed with transition-state analogue renin inhibitors were determined. The structure of a cyclic peptide inhibitor (PD-129,541) complexed with the proteinase was solved to 2.5 A resolution. This inhibitor has low affinity for human renin yet binds very tightly to the yeast proteinase (K(i)=4 nM). The high affinity of this inhibitor can be attributed to its bulky cyclic moiety spanning P(2)-P(3)' and other residues that appear to optimally fit the binding sub-sites of the enzyme. Superposition of the saccharopepsin structure on that of renin showed that a movement of the loop 286-301 relative to renin facilitates tighter binding of this inhibitor to saccharopepsin. Our 2.8 A resolution structure of the complex with CP-108,420 shows that its benzimidazole P(3 )replacement retains one of the standard hydrogen bonds that normally involve the inhibitor's main-chain. This suggests a non-peptide lead in overcoming the problem of susceptible peptide bonds in the design of aspartic proteinase inhibitors. CP-72,647 which possesses a basic histidine residue at P(2), has a high affinity for renin (K(i)=5 nM) but proves to be a poor inhibitor for saccharopepsin (K(i)=3.7 microM). This may stem from the fact that the histidine residue would not bind favourably with the predominantly hydrophobic S(2) sub-site of saccharopepsin.

About this StructureAbout this Structure

1FQ7 is a Single protein structure of sequence from Saccharomyces cerevisiae with , , , , and as ligands. Active as Saccharopepsin, with EC number 3.4.23.25 Full crystallographic information is available from OCA.

ReferenceReference

X-ray structures of five renin inhibitors bound to saccharopepsin: exploration of active-site specificity., Cronin NB, Badasso MO, J Tickle I, Dreyer T, Hoover DJ, Rosati RL, Humblet CC, Lunney EA, Cooper JB, J Mol Biol. 2000 Nov 10;303(5):745-60. PMID:11061973

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-[[Image:1fq7.jpg|left|200px]]<br /><applet load="1fq7" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1fq7.jpg|left|200px]]<br /><applet load="1fq7" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1fq7, resolution 2.8&Aring;" />
 '''X-RAY STRUCTURE OF INHIBITOR CP-72,647 BOUND TO SACCHAROPEPSIN'''<br />
 ==Overview==
-Saccharopepsin is a vacuolar aspartic proteinase involved in activation of, a number of hydrolases. The enzyme has great structural homology to, mammalian aspartic proteinases including human renin and we have used it, as a model system to study the binding of renin inhibitors by X-ray, crystallography. Five medium-to-high resolution structures of, saccharopepsin complexed with transition-state analogue renin inhibitors, were determined. The structure of a cyclic peptide inhibitor (PD-129,541), complexed with the proteinase was solved to 2.5 A resolution. This, inhibitor has low affinity for human renin yet binds very tightly to the, yeast proteinase (K(i)=4 nM). The high affinity of this inhibitor can be, attributed to its bulky cyclic moiety spanning P(2)-P(3)' and other, residues that appear to optimally fit the binding sub-sites of the enzyme., Superposition of the saccharopepsin structure on that of renin showed that, a movement of the loop 286-301 relative to renin facilitates tighter, binding of this inhibitor to saccharopepsin. Our 2.8 A resolution, structure of the complex with CP-108,420 shows that its benzimidazole P(3, )replacement retains one of the standard hydrogen bonds that normally, involve the inhibitor's main-chain. This suggests a non-peptide lead in, overcoming the problem of susceptible peptide bonds in the design of, aspartic proteinase inhibitors. CP-72,647 which possesses a basic, histidine residue at P(2), has a high affinity for renin (K(i)=5 nM) but, proves to be a poor inhibitor for saccharopepsin (K(i)=3.7 microM). This, may stem from the fact that the histidine residue would not bind, favourably with the predominantly hydrophobic S(2) sub-site of, saccharopepsin.
+Saccharopepsin is a vacuolar aspartic proteinase involved in activation of a number of hydrolases. The enzyme has great structural homology to mammalian aspartic proteinases including human renin and we have used it as a model system to study the binding of renin inhibitors by X-ray crystallography. Five medium-to-high resolution structures of saccharopepsin complexed with transition-state analogue renin inhibitors were determined. The structure of a cyclic peptide inhibitor (PD-129,541) complexed with the proteinase was solved to 2.5 A resolution. This inhibitor has low affinity for human renin yet binds very tightly to the yeast proteinase (K(i)=4 nM). The high affinity of this inhibitor can be attributed to its bulky cyclic moiety spanning P(2)-P(3)' and other residues that appear to optimally fit the binding sub-sites of the enzyme. Superposition of the saccharopepsin structure on that of renin showed that a movement of the loop 286-301 relative to renin facilitates tighter binding of this inhibitor to saccharopepsin. Our 2.8 A resolution structure of the complex with CP-108,420 shows that its benzimidazole P(3 )replacement retains one of the standard hydrogen bonds that normally involve the inhibitor's main-chain. This suggests a non-peptide lead in overcoming the problem of susceptible peptide bonds in the design of aspartic proteinase inhibitors. CP-72,647 which possesses a basic histidine residue at P(2), has a high affinity for renin (K(i)=5 nM) but proves to be a poor inhibitor for saccharopepsin (K(i)=3.7 microM). This may stem from the fact that the histidine residue would not bind favourably with the predominantly hydrophobic S(2) sub-site of saccharopepsin.
 ==About this Structure==
-FQ7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with NAG, BOC, PHE, HIS, CAL and NME as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Saccharopepsin Saccharopepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.25 3.4.23.25] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1FQ7 OCA].
+FQ7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=BOC:'>BOC</scene>, <scene name='pdbligand=PHE:'>PHE</scene>, <scene name='pdbligand=HIS:'>HIS</scene>, <scene name='pdbligand=CAL:'>CAL</scene> and <scene name='pdbligand=NME:'>NME</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Saccharopepsin Saccharopepsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.23.25 3.4.23.25] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FQ7 OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Saccharopepsin]]
 [[Category: Single protein]]
-[[Category: Badasso, M.O.]]
+[[Category: Badasso, M O.]]
-[[Category: Cooper, J.B.]]
+[[Category: Cooper, J B.]]
-[[Category: Cronin, N.B.]]
+[[Category: Cronin, N B.]]
 [[Category: Dreyer, T.]]
-[[Category: Hoover, D.J.]]
+[[Category: Hoover, D J.]]
-[[Category: Humblet, C.C.]]
+[[Category: Humblet, C C.]]
-[[Category: Lunney, E.A.]]
+[[Category: Lunney, E A.]]
-[[Category: Rosati, R.L.]]
+[[Category: Rosati, R L.]]
-[[Category: Tickle, I.J.]]
+[[Category: Tickle, I J.]]
 [[Category: BOC]]
 [[Category: CAL]]
@@ Line 32: / Line 32: @@
 [[Category: t-boc terminal group]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 15:09:04 2007''
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