Structure of native protein C inhibitor provides insight into its multiple functions
(2007) In Journal of Biological Chemistry 282(18). p.13759-13768- Abstract
- 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. To gain insight into the molecular mechanisms utilized by PCI we developed a robust expression system in Escherichia 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... (More)
- 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. To gain insight into the molecular mechanisms utilized by PCI we developed a robust expression system in Escherichia 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. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/663053
- author
- Liu, Wei ; Adams, Ty E. ; Kjellberg, Margareta LU ; Stenflo, Johan LU and Huntington, James A
- organization
- publishing date
- 2007
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 282
- issue
- 18
- pages
- 13759 - 13768
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- wos:000246060300066
- scopus:34250332236
- ISSN
- 1083-351X
- DOI
- 10.1074/jbc.M701074200
- language
- English
- LU publication?
- yes
- id
- 1b430420-f4da-45e6-b477-15a350c607f2 (old id 663053)
- date added to LUP
- 2016-04-01 12:29:03
- date last changed
- 2022-05-19 06:14:10
@article{1b430420-f4da-45e6-b477-15a350c607f2, abstract = {{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. To gain insight into the molecular mechanisms utilized by PCI we developed a robust expression system in Escherichia 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.}}, author = {{Liu, Wei and Adams, Ty E. and Kjellberg, Margareta and Stenflo, Johan and Huntington, James A}}, issn = {{1083-351X}}, language = {{eng}}, number = {{18}}, pages = {{13759--13768}}, publisher = {{American Society for Biochemistry and Molecular Biology}}, series = {{Journal of Biological Chemistry}}, title = {{Structure of native protein C inhibitor provides insight into its multiple functions}}, url = {{http://dx.doi.org/10.1074/jbc.M701074200}}, doi = {{10.1074/jbc.M701074200}}, volume = {{282}}, year = {{2007}}, }