View source for 2pk4


==THE REFINED STRUCTURE OF THE EPSILON-AMINOCAPROIC ACID COMPLEX OF HUMAN PLASMINOGEN KRINGLE==
<StructureSection load='2pk4' size='340' side='right'caption='[[2pk4]], [[Resolution|resolution]] 2.25&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2pk4]] is a 1 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=2PK4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PK4 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]] 2.25&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACA:6-AMINOHEXANOIC+ACID'>ACA</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=2pk4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2pk4 OCA], [https://pdbe.org/2pk4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2pk4 RCSB], [https://www.ebi.ac.uk/pdbsum/2pk4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2pk4 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/PLMN_HUMAN PLMN_HUMAN] Defects in PLG are the cause of plasminogen deficiency (PLGD) [MIM:[https://omim.org/entry/217090 217090]. PLGD is characterized by decreased serum plasminogen activity. Two forms of the disorder are distinguished: type 1 deficiency is additionally characterized by decreased plasminogen antigen levels and clinical symptoms, whereas type 2 deficiency, also known as dysplasminogenemia, is characterized by normal, or slightly reduced antigen levels, and absence of clinical manifestations. Plasminogen deficiency type 1 results in markedly impaired extracellular fibrinolysis and chronic mucosal pseudomembranous lesions due to subepithelial fibrin deposition and inflammation. The most common clinical manifestation of type 1 deficiency is ligneous conjunctivitis in which pseudomembranes formation on the palpebral surfaces of the eye progresses to white, yellow-white, or red thick masses with a wood-like consistency that replace the normal mucosa.<ref>PMID:1986355</ref> <ref>PMID:8392398</ref> <ref>PMID:6216475</ref> <ref>PMID:6238949</ref> <ref>PMID:1427790</ref> <ref>PMID:9242524</ref> <ref>PMID:9858247</ref> <ref>PMID:10233898</ref> 
== Function ==
[https://www.uniprot.org/uniprot/PLMN_HUMAN PLMN_HUMAN] Plasmin dissolves the fibrin of blood clots and acts as a proteolytic factor in a variety of other processes including embryonic development, tissue remodeling, tumor invasion, and inflammation. In ovulation, weakens the walls of the Graafian follicle. It activates the urokinase-type plasminogen activator, collagenases and several complement zymogens, such as C1 and C5. Cleavage of fibronectin and laminin leads to cell detachment and apoptosis. Also cleaves fibrin, thrombospondin and von Willebrand factor. Its role in tissue remodeling and tumor invasion may be modulated by CSPG4. Binds to cells.<ref>PMID:14699093</ref>   Angiostatin is an angiogenesis inhibitor that blocks neovascularization and growth of experimental primary and metastatic tumors in vivo.<ref>PMID:14699093</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/pk/2pk4_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2pk4 ConSurf].
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== Publication Abstract from PubMed ==
The crystallographic structure of the plasminogen kringle 4-epsilon-aminocaproic acid (ACA) complex (K4-ACA) has been solved by molecular replacement rotation-translation methods utilizing the refined apo-K4 structure as a search model (Mulichak et al., 1991), and it has been refined to an R value of 0.148 at 2.25-A resolution. The K4-ACA structure consists of two interkringle residues, the kringle along with the ACA ligand, and 106 water molecules. The lysine-binding site has been confirmed to be a relatively open and shallow depression, lined by aromatic rings of Trp62, Phe64, and Trp72, which provide a highly nonpolar environment between doubly charged anionic and cationic centers formed by Asp55/Asp57 and Lys35/Arg71. A zwitterionic ACA ligand molecule is held by hydrogen-bonded ion pair interactions and van der Waals contacts between the charged centers. The lysine-binding site of apo-K4 and K4-ACA have been compared: the rms differences in main-chain and side-chain positions are 0.25 and 0.69 A, respectively, both practically within error of the determinations. The largest deviations in the binding site are due to different crystal packing interactions. Thus, the lysine-binding site appears to be preformed, and lysine binding does not require conformational changes of the host. The results of NMR studies of lysine binding with K4 are correlated with the structure of K4-ACA and agree well.

The refined structure of the epsilon-aminocaproic acid complex of human plasminogen kringle 4.,Wu TP, Padmanabhan K, Tulinsky A, Mulichak AM Biochemistry. 1991 Oct 29;30(43):10589-94. PMID:1657149<ref>PMID:1657149</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2pk4" style="background-color:#fffaf0;"></div>

==See Also==
*[[Plasminogen 3D structures|Plasminogen 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Tulinsky A]]
[[Category: Wu T-P]]