View source for 2hi9

[[Image:2hi9.jpg|left|200px]]<br /><applet load="2hi9" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="2hi9, resolution 2.300&Aring;" />
'''Crystal Structure of human native protein C inhibitor'''<br />

==Overview==
Protein C inhibitor (PCI) is a multifunctional serpin with wide-ranging, protease inhibitory functions, unique cofactor binding activities and, potential non-inhibitory functions akin to the hormone transporting, serpins. In order to gain insight into the molecular mechanisms utilized, by PCI we developed a robust expression system in E. coli and solved the, crystal structure of PCI in its native state. The five monomers obtained, from our two crystal forms provide an NMR-like ensemble revealing regions, of inherent flexibility. The reactive center loop (RCL) of PCI is long and, highly flexible with no evidence of hinge region incorporation into, beta-sheet A, as seen for other heparin binding serpins. We adapted an, extrinsic fluorescence method for determining dissociation constants for, heparin, and find that the N-terminal tail of PCI and residues adjacent to, helix H are not involved in heparin binding. The minimal heparin length, capable of tight binding to PCI was determined to be chains of eight, monosaccharide units. A large hydrophobic pocket occupied by hydrophobic, crystal contacts was found in an analogous position to the hormone binding, site in thyroxine binding globulin. In conclusion, the data presented here, provide important insights into the mechanisms by which PCI exercises its, multiple inhibitory and non-inhibitory functions.

==Disease==
Known diseases associated with this structure: Protein C inhibitor deficiency OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=601841 601841]]

==About this Structure==
2HI9 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=CIT:'>CIT</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HI9 OCA]. 

==Reference==
Structure of native protein C inhibitor provides insight into its multiple functions., Li W, Adams TE, Kjellberg M, Stenflo J, Huntington JA, J Biol Chem. 2007 Mar 2;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17337440 17337440]
[[Category: Homo sapiens]]
[[Category: Single protein]]
[[Category: Adams, T.E.]]
[[Category: Huntington, J.A.]]
[[Category: Li, W.]]
[[Category: CIT]]
[[Category: GOL]]
[[Category: acrosin inhibitor]]
[[Category: activated protein c inhibitor]]
[[Category: coagulation]]
[[Category: haemostasis]]
[[Category: serine protease inhibitor]]
[[Category: serpin]]
[[Category: thrombin inhibitor]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 17:32:22 2008''