View source for 1lq8


==Crystal structure of cleaved protein C inhibitor==
<StructureSection load='1lq8' size='340' side='right'caption='[[1lq8]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1lq8]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LQ8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LQ8 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1lq8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lq8 OCA], [https://pdbe.org/1lq8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lq8 RCSB], [https://www.ebi.ac.uk/pdbsum/1lq8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lq8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/IPSP_HUMAN IPSP_HUMAN] Heparin-dependent serine protease inhibitor acting in body fluids and secretions. Inactivates serine proteases by binding irreversibly to their serine activation site. Involved in the regulation of intravascular and extravascular proteolytic activities. Plays hemostatic roles in the blood plasma. Acts as a procoagulant and proinflammatory factor by inhibiting the anticoagulant activated protein C factor as well as the generation of activated protein C factor by the thrombin/thrombomodulin complex. Acts as an anticoagulant factor by inhibiting blood coagulation factors like prothrombin, factor XI, factor Xa, plasma kallikrein and fibrinolytic enzymes such as tissue- and urinary-type plasminogen activators. In seminal plasma, inactivates several serine proteases implicated in the reproductive system. Inhibits the serpin acrosin; indirectly protects component of the male genital tract from being degraded by excessive released acrosin. Inhibits tissue-and urinary-type plasminogen activator, prostate-specific antigen and kallikrein activities; has a control on the sperm motility and fertilization. Inhibits the activated protein C-catalyzed degradation of SEMG1 and SEMG2; regulates the degradation of semenogelin during the process of transfer of spermatozoa from the male reproductive tract into the female tract. In urine, inhibits urinary-type plasminogen activator and kallikrein activities. Inactivates membrane-anchored serine proteases activities such as MPRSS7 and TMPRSS11E. Inhibits urinary-type plasminogen activator-dependent tumor cell invasion and metastasis. May also play a non-inhibitory role in seminal plasma and urine as a hydrophobic hormone carrier by its binding to retinoic acid.<ref>PMID:6323392</ref> <ref>PMID:3501295</ref> <ref>PMID:2844223</ref> <ref>PMID:1725227</ref> <ref>PMID:7521127</ref> <ref>PMID:7548057</ref> <ref>PMID:8536714</ref> <ref>PMID:8665956</ref> <ref>PMID:9473218</ref> <ref>PMID:9510955</ref> <ref>PMID:9556620</ref> <ref>PMID:10340997</ref> <ref>PMID:11722589</ref> <ref>PMID:14696115</ref> <ref>PMID:15328353</ref> <ref>PMID:15140131</ref> <ref>PMID:15853774</ref> <ref>PMID:18467335</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/lq/1lq8_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1lq8 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Protein C inhibitor (PCI) is a member of the serpin family that has many biological functions. In blood it acts as a procoagulant, and, in the seminal vesicles, it is required for spermatogenesis. The activity of PCI is affected by heparin binding in a manner unique among the heparin binding serpins, and, in addition, PCI binds hydrophobic hormones with apparent specificity for retinoids. Here we present the 2.4 A crystallographic structure of reactive center loop (RCL) cleaved PCI. A striking feature of the structure is a two-turn N-terminal shortening of helix A, which creates a large hydrophobic pocket that docking studies indicate to be the retinoid binding site. On the basis of surface electrostatic properties, a novel mechanism for heparin activation is proposed.

Crystal structure of protein C inhibitor provides insights into hormone binding and heparin activation.,Huntington JA, Kjellberg M, Stenflo J Structure. 2003 Feb;11(2):205-15. PMID:12575940<ref>PMID:12575940</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1lq8" style="background-color:#fffaf0;"></div>

==See Also==
*[[Plasminogen activator inhibitor|Plasminogen activator inhibitor]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Huntington JA]]
[[Category: Kjellberg M]]
[[Category: Stenflo J]]