1z8g: Difference between revisions
New page: left|200px<br /> <applet load="1z8g" size="450" color="white" frame="true" align="right" spinBox="true" caption="1z8g, resolution 1.55Å" /> '''Crystal structure o... |
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[[Image:1z8g.gif|left|200px]]<br /> | [[Image:1z8g.gif|left|200px]]<br /><applet load="1z8g" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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caption="1z8g, resolution 1.55Å" /> | caption="1z8g, resolution 1.55Å" /> | ||
'''Crystal structure of the extracellular region of the transmembrane serine protease hepsin with covalently bound preferred substrate.'''<br /> | '''Crystal structure of the extracellular region of the transmembrane serine protease hepsin with covalently bound preferred substrate.'''<br /> | ||
==Overview== | ==Overview== | ||
Hepsin is a membrane-anchored, trypsin-like serine protease with prominent | Hepsin is a membrane-anchored, trypsin-like serine protease with prominent expression in the human liver and tumours of the prostate and ovaries. To better understand the biological functions of hepsin, we identified macromolecular substrates employing a tetrapeptide PS-SCL (positional scanning-synthetic combinatorial library) screen that rapidly determines the P1-P4 substrate specificity. Hepsin exhibited strong preference at the P1 position for arginine over lysine, and favoured threonine, leucine or asparagine at the P2, glutamine or lysine at the P3, and proline or lysine at the P4 position. The relative activity of hepsin toward individual AMC (7-amino-4-methylcoumarin)-tetrapeptides was generally consistent with the overall peptide profiling results derived from the PC-SCL screen. The most active tetrapeptide substrate Ac (acetyl)-KQLR-AMC matched with the activation cleavage site of the hepatocyte growth factor precursor sc-HGF (single-chain HGF), KQLR downward arrowVVNG (where downward arrow denotes the cleavage site), as identified by a database analysis of trypsin-like precursors. X-ray crystallographic studies with KQLR chloromethylketone showed that the KQLR peptide fits well into the substrate-binding cleft of hepsin. This hepsin-processed HGF induced c-Met receptor tyrosine phosphorylation in SKOV-3 ovarian cancer cells, indicating that the hepsin-cleaved HGF is biologically active. Activation cleavage site mutants of sc-HGF with predicted non-preferred sequences, DPGR downward arrowVVNG or KQLQ downward arrowVVNG, were not processed, illustrating that the P4-P1 residues can be important determinants for substrate specificity. In addition to finding macromolecular hepsin substrates, the extracellular inhibitors of the HGF activator, HAI-1 and HAI-2, were potent inhibitors of hepsin activity (IC50 4+/-0.2 nM and 12+/-0.5 nM respectively). Together, our findings suggest that the HGF precursor is a potential in vivo substrate for hepsin in tumours, where hepsin expression is dysregulated and may influence tumorigenesis through inappropriate activation and/or regulation of HGF receptor (c-Met) functions. | ||
==About this Structure== | ==About this Structure== | ||
1Z8G is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with ACE as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1Z8G is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=ACE:'>ACE</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z8G OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Aaron, W.]] | [[Category: Aaron, W.]] | ||
[[Category: Austin, R | [[Category: Austin, R J.]] | ||
[[Category: Bhatt, A | [[Category: Bhatt, A S.]] | ||
[[Category: Cao, P.]] | [[Category: Cao, P.]] | ||
[[Category: Choe, Y.]] | [[Category: Choe, Y.]] | ||
[[Category: Craik, C | [[Category: Craik, C S.]] | ||
[[Category: Cutler, G.]] | [[Category: Cutler, G.]] | ||
[[Category: Gabriele, T.]] | [[Category: Gabriele, T.]] | ||
| Line 25: | Line 24: | ||
[[Category: Hoey, T.]] | [[Category: Hoey, T.]] | ||
[[Category: Meininger, D.]] | [[Category: Meininger, D.]] | ||
[[Category: Piper, D | [[Category: Piper, D E.]] | ||
[[Category: Walker, N.]] | [[Category: Walker, N.]] | ||
[[Category: ACE]] | [[Category: ACE]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:13:04 2008'' | ||
Revision as of 17:13, 21 February 2008
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Crystal structure of the extracellular region of the transmembrane serine protease hepsin with covalently bound preferred substrate.
OverviewOverview
Hepsin is a membrane-anchored, trypsin-like serine protease with prominent expression in the human liver and tumours of the prostate and ovaries. To better understand the biological functions of hepsin, we identified macromolecular substrates employing a tetrapeptide PS-SCL (positional scanning-synthetic combinatorial library) screen that rapidly determines the P1-P4 substrate specificity. Hepsin exhibited strong preference at the P1 position for arginine over lysine, and favoured threonine, leucine or asparagine at the P2, glutamine or lysine at the P3, and proline or lysine at the P4 position. The relative activity of hepsin toward individual AMC (7-amino-4-methylcoumarin)-tetrapeptides was generally consistent with the overall peptide profiling results derived from the PC-SCL screen. The most active tetrapeptide substrate Ac (acetyl)-KQLR-AMC matched with the activation cleavage site of the hepatocyte growth factor precursor sc-HGF (single-chain HGF), KQLR downward arrowVVNG (where downward arrow denotes the cleavage site), as identified by a database analysis of trypsin-like precursors. X-ray crystallographic studies with KQLR chloromethylketone showed that the KQLR peptide fits well into the substrate-binding cleft of hepsin. This hepsin-processed HGF induced c-Met receptor tyrosine phosphorylation in SKOV-3 ovarian cancer cells, indicating that the hepsin-cleaved HGF is biologically active. Activation cleavage site mutants of sc-HGF with predicted non-preferred sequences, DPGR downward arrowVVNG or KQLQ downward arrowVVNG, were not processed, illustrating that the P4-P1 residues can be important determinants for substrate specificity. In addition to finding macromolecular hepsin substrates, the extracellular inhibitors of the HGF activator, HAI-1 and HAI-2, were potent inhibitors of hepsin activity (IC50 4+/-0.2 nM and 12+/-0.5 nM respectively). Together, our findings suggest that the HGF precursor is a potential in vivo substrate for hepsin in tumours, where hepsin expression is dysregulated and may influence tumorigenesis through inappropriate activation and/or regulation of HGF receptor (c-Met) functions.
About this StructureAbout this Structure
1Z8G is a Single protein structure of sequence from Homo sapiens with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Hepatocyte growth factor is a preferred in vitro substrate for human hepsin, a membrane-anchored serine protease implicated in prostate and ovarian cancers., Herter S, Piper DE, Aaron W, Gabriele T, Cutler G, Cao P, Bhatt AS, Choe Y, Craik CS, Walker N, Meininger D, Hoey T, Austin RJ, Biochem J. 2005 Aug 15;390(Pt 1):125-36. PMID:15839837
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