Chemokine CXCL8 and its receptor CXCR1 are key mediators in combating infection and have also been implicated in the pathophysiology of various diseases including chronic obstructive pulmonary disease (COPD) and cancer. CXCL8 exists as monomers and dimers but monomer alone binds CXCR1 with high affinity. CXCL8 function involves binding two distinct CXCR1 sites – the N-terminal domain (Site-I) and the extracellular/transmembrane domain (Site-II). Therefore, higher monomer affinity could be due to stronger binding at Site-I or Site-II or both. We have now characterized the binding of a human CXCR1 N-terminal domain peptide (hCXCR1Ndp) to WT CXCL8 under conditions where it exists as both monomers and dimers. We show that the WT monomer binds the CXCR1 N-domain with much higher affinity and that binding is coupled to dimer dissociation. We also characterized the binding of two CXCL8 monomer variants and a trapped dimer to two different hCXCR1Ndp constructs, and observe that the monomer binds with ~10- to 100-fold higher affinity than the dimer. Our studies also show that the binding constants of monomer and dimer to the receptor peptides, and the dimer dissociation constant, can vary significantly as a function of pH and buffer, and so the ability to observe WT monomer peaks is critically dependent on NMR experimental conditions. We conclude that the monomer is the high affinity CXCR1 agonist, that Site-I interactions play a dominant role in determining monomer vs. dimer affinity, and that the dimer plays an indirect role in regulating monomer function.
[NMR paper] Solution NMR characterization of WT CXCL8 monomer and dimer binding to CXCR1 N-terminal domain.
Solution NMR characterization of WT CXCL8 monomer and dimer binding to CXCR1 N-terminal domain.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--media.wiley.com-assets-2250-98-WileyOnlineLibrary-Button_120x27px_FullText.gif Related Articles Solution NMR characterization of WT CXCL8 monomer and dimer binding to CXCR1 N-terminal domain.
Protein Sci. 2014 Oct 18;
Authors: Joseph PR, Rajarathnam K
Abstract
Chemokine CXCL8 and its receptor CXCR1 are key mediators in combating infection and have also been...
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10-21-2014 11:31 PM
Solution NMR characterization of WT CXCL8 monomer and dimer binding to CXCR1 N-terminal domain
Solution NMR characterization of WT CXCL8 monomer and dimer binding to CXCR1 N-terminal domain
Abstract
Chemokine CXCL8 and its receptor CXCR1 are key mediators in combating infection and have also been implicated in the pathophysiology of various diseases including chronic obstructive pulmonary disease (COPD) and cancer. CXCL8 exists as monomers and dimers but monomer alone binds CXCR1 with high affinity. CXCL8 function involves binding two distinct CXCR1 sites – the N-terminal domain (Site-I) and the extracellular/transmembrane domain (Site-II). Therefore, higher monomer affinity...
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10-18-2014 09:26 PM
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain
March 2012
Publication year: 2012
Source:Biochimie, Volume 94, Issue 3</br>
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The insulin-like growth factor binding proteins are a family of six proteins (IGFBP-1 to -6) that bind insulin-like growth factors-I and -II (IGF-I/II) with high affinity. In addition to regulating IGF actions, IGFBPs have IGF-independent functions. IGFBP-2, the largest member of this family, is over-expressed in many cancers and has been proposed as a possible target for the...
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02-03-2013 10:13 AM
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain.
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain.
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain.
Biochimie. 2011 Sep 22;
Authors: Galea CA, Mobli M, McNeil KA, Mulhern TD, Wallace JC, King GF, Forbes BE, Norton RS
Abstract
The insulin-like growth factor binding proteins are a family of six proteins (IGFBP-1 to 6) that bind insulin-like growth factors-I and -II (IGF-I/II) with high affinity. In addition...
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09-30-2011 06:00 AM
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain.
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain.
Insulin-like growth factor binding protein-2: NMR analysis and structural characterization of the N-terminal domain.
Biochimie. 2011 Sep 22;
Authors: Galea CA, Mobli M, McNeil KA, Mulhern TD, Wallace JC, King GF, Forbes BE, Norton RS
Abstract
The insulin-like growth factor binding proteins are a family of six proteins (IGFBP-1 to 6) that bind insulin-like growth factors-I and -II (IGF-I/II) with high affinity. In...
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09-30-2011 05:59 AM
[NMR paper] Solution structure of the carboxyl-terminal domain of RAP74 and NMR characterization
Solution structure of the carboxyl-terminal domain of RAP74 and NMR characterization of the FCP1-binding sites of RAP74 and human TFIIB.
Solution structure of the carboxyl-terminal domain of RAP74 and NMR characterization of the FCP1-binding sites of RAP74 and human TFIIB.
Biochemistry. 2003 Feb 18;42(6):1460-9
Authors: Nguyen BD, Chen HT, Kobor MS, Greenblatt J, Legault P, Omichinski JG
FCP1 (TFIIF-associated CTD phosphatase) is the only known phosphatase specific for the phosphorylated CTD of RNAP II. The phosphatase activity of FCP1 is...
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11-24-2010 09:01 PM
[NMR paper] NMR spectroscopic studies of the DNA-binding domain of the monomer-binding nuclear or
NMR spectroscopic studies of the DNA-binding domain of the monomer-binding nuclear orphan receptor, human estrogen related receptor-2. The carboxyl-terminal extension to the zinc-finger region is unstructured in the free form of the protein.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--highwire.stanford.edu-icons-externalservices-pubmed-standard-jbc_full_free.gif Related Articles NMR spectroscopic studies of the DNA-binding domain of the monomer-binding nuclear orphan receptor, human estrogen related receptor-2. The carboxyl-terminal extension to the zinc-finger region...