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Haugaard-Kedström, Linda M.
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Publications (10 of 17) Show all publications
Nilsson, P. H., Johnson, C., Pischke, S. E., Fure, H., Landsem, A., Bergseth, G., . . . Mollnes, T. E. (2017). Characterization of a novel whole blood model for the study of thrombin in complement activation and inflammation. Paper presented at 16th European Meeting on Complement in Human Disease (EMCHD), SEP 08-12, 2017, Copenhagen, DENMARK. Molecular Immunology, 89, 136-137
Open this publication in new window or tab >>Characterization of a novel whole blood model for the study of thrombin in complement activation and inflammation
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2017 (English)In: Molecular Immunology, ISSN 0161-5890, E-ISSN 1872-9142, Vol. 89, p. 136-137Article in journal, Meeting abstract (Other academic) Published
National Category
Immunology
Research subject
Biomedical Sciences, Immunology
Identifiers
urn:nbn:se:lnu:diva-68146 (URN)10.1016/j.molimm.2017.06.075 (DOI)000410014500056 ()
Conference
16th European Meeting on Complement in Human Disease (EMCHD), SEP 08-12, 2017, Copenhagen, DENMARK
Available from: 2017-10-02 Created: 2017-10-02 Last updated: 2018-11-16Bibliographically approved
Haugaard-Kedström, L. M., Hossain, M. A., Daly, N. L., Bathgate, R. A., Rinderknecht, E., Wade, J. D., . . . Rosengren, K. J. (2015). Solution Structure, Aggregation Behavior, and Flexibility of Human Relaxin-2.. ACS Chemical Biology, 10(3), 891-900
Open this publication in new window or tab >>Solution Structure, Aggregation Behavior, and Flexibility of Human Relaxin-2.
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2015 (English)In: ACS Chemical Biology, ISSN 1554-8929, E-ISSN 1554-8937, Vol. 10, no 3, p. 891-900Article in journal (Refereed) Published
Abstract [en]

Relaxin is a member of the relaxin/insulin peptide hormone superfamily and is characterized by a two-chain structure constrained by three disulfide bonds. Relaxin is a pleiotropic hormone and involved in a number of physiological and pathogenic processes, including collagen and cardiovascular regulation and tissue remodelling during pregnancy and cancer. Crystallographic and ultracentrifugation experiments have revealed that the human form of relaxin, H2 relaxin, self-associates into dimers, but the significance of this is poorly understood. Here, we present the NMR structure of a monomeric, amidated form of H2 relaxin and compare its features and behavior in solution to those of native H2 relaxin. The overall structure of H2 relaxin is retained in the monomeric form. H2 relaxin amide is fully active at the relaxin receptor RXFP1 and thus dimerization is not required for biological activity. Analysis of NMR chemical shifts and relaxation parameters identified internal motion in H2 relaxin at the pico-nanosecond and milli-microsecond time scales, which is commonly seen in other relaxin and insulin peptides and might be related to function.

National Category
Biochemistry and Molecular Biology
Research subject
Natural Science, Biomedical Sciences
Identifiers
urn:nbn:se:lnu:diva-39719 (URN)10.1021/cb500918v (DOI)000351558700028 ()25547165 (PubMedID)2-s2.0-84925365962 (Scopus ID)
Available from: 2015-02-04 Created: 2015-02-04 Last updated: 2017-12-05Bibliographically approved
Andersson, H. S., Figueredo, S. M., Haugaard-Kedström, L. M., Bengtsson, E., Daly, N. L., Qu, X., . . . Rosengren, K. J. (2012). The alpha-defensin salt-bridge induces backbone stability to facilitate folding and confer proteolytic resistance. Amino Acids, 43(4), 1471-1483
Open this publication in new window or tab >>The alpha-defensin salt-bridge induces backbone stability to facilitate folding and confer proteolytic resistance
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2012 (English)In: Amino Acids, ISSN 0939-4451, E-ISSN 1438-2199, Vol. 43, no 4, p. 1471-1483Article in journal (Refereed) Published
Abstract [en]

Salt-bridge interactions between acidic and basic amino acids contribute to the structural stability of proteins and to protein-protein interactions. A conserved salt-bridge is a canonical feature of the alpha-defensin antimicrobial peptide family, but the role of this common structural element has not been fully elucidated. We have investigated mouse Paneth cell alpha-defensin cryptdin-4 (Crp4) and peptide variants with mutations at Arg(7) or Glu(15) residue positions to disrupt the salt-bridge and assess the consequences on Crp4 structure, function, and stability. NMR analyses showed that both (R7G)-Crp4 and (E15G)-Crp4 adopt native-like structures, evidence of fold plasticity that allows peptides to reshuffle side chains and stabilize the structure in the absence of the salt-bridge. In contrast, introduction of a large hydrophobic side chain at position 15, as in (E15L)-Crp4 cannot be accommodated in the context of the Crp4 primary structure. Regardless of which side of the salt-bridge was mutated, salt-bridge variants retained bactericidal peptide activity with differential microbicidal effects against certain bacterial cell targets, confirming that the salt-bridge does not determine bactericidal activity per se. The increased structural flexibility induced by salt-bridge disruption enhanced peptide sensitivity to proteolysis. Although sensitivity to proteolysis by MMP7 was unaffected by most Arg(7) and Glu(15) substitutions, every salt-bridge variant was degraded extensively by trypsin. Moreover, the salt-bridge facilitates adoption of the characteristic alpha-defensin fold as shown by the impaired in vitro refolding of (E15D)-proCrp4, the most conservative salt-bridge disrupting replacement. In Crp4, therefore, the canonical alpha-defensin salt-bridge facilitates adoption of the characteristic alpha-defensin fold, which decreases structural flexibility and confers resistance to degradation by proteinases.

Keywords
Defensin, Cryptdin-4, Crp4, Salt-bridge, Structure, Folding, Proteolytic stability
National Category
Organic Chemistry
Research subject
Chemistry, Biochemistry; Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-22288 (URN)10.1007/s00726-012-1220-3 (DOI)000309070700007 ()2-s2.0-84867577474 (Scopus ID)
Available from: 2012-11-06 Created: 2012-11-06 Last updated: 2017-04-18Bibliographically approved
Haugaard-Kedström, L. M., Shabanpoor, F., Hossain, M. A., Clark, R., Ryan, P., Craik, D., . . . Rosengren, K. J. (2011). Design, synthesis, and characterization of a single-chain peptide antagonist for the relaxin-3 receptor RXFP3. Journal of the American Chemical Society, 133(13), 4965-4974
Open this publication in new window or tab >>Design, synthesis, and characterization of a single-chain peptide antagonist for the relaxin-3 receptor RXFP3
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2011 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 133, no 13, p. 4965-4974Article in journal (Refereed) Published
National Category
Chemical Sciences
Research subject
Chemistry, Biochemistry
Identifiers
urn:nbn:se:lnu:diva-9785 (URN)10.1021/ja110567j (DOI)2-s2.0-79953858024 (Scopus ID)
Available from: 2010-12-21 Created: 2010-12-20 Last updated: 2017-04-19Bibliographically approved
Haugaard-Kedström, L. M. (2011). Structure and function of relaxins. (Doctoral dissertation). Växjö, Kalmar: Linneaus University Press
Open this publication in new window or tab >>Structure and function of relaxins
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The relaxin/insulin superfamily is a group of peptide hormones that consists of ten members in human, namely relaxins 1-3, insulin-like peptides (INSL) 3-6, insulin and insulin-like growth factors (IGF) I-II. These peptides have various functions in the body, such as regulating growth, blood glucose levels,  collagen metabolism, germ cell maturation and appetite. Misregulation of these mechanisms is associated with disease and accordingly they are of interest as potential pharmaceutical targets. Structurally the hormones are characterised by two peptide chains, A and B, which are held together by one intra A-chain and two inter chain disulfide bonds. Four different G-protein coupled receptors (GPCR) called relaxin family peptide receptor (RXFP) 1-4 have been found to respond to stimuli by different relaxin peptides. RXFP3 and RXFP4 are classic peptide ligand GPCRs, whereas RXFP1 and RXFP2 are characterised by a large extracellular leucine rich-repeat domain. Relaxin-3, which is the relaxin family ancestor, is the only relaxin peptide known to be able to bind and activate both subtypes of GPCRs, namely RXFP1, RXFP3 and RXFP4.

The aim of this thesis was to analyse the structure-function relationship of the relaxin ligands and receptors, and to use this information to develop selective ligands for the relaxin receptors, which can be used as drug leads or pharmacological tools for investigating the physiological roles of the RXFPs.

The 3D structures of native INSL5 and relaxin-2 were determined by solution NMR spectroscopy. The peptides showed an insulin/relaxin-like overall fold. A relaxin chimera peptide, consisting of the A-chain from INSL5 and the B-chain from relaxin-3, R3/I5, which has been shown to be selective for RXFP3 and RXFP4 over RXFP1, was also subjected to NMR studies. The R3/I5 peptide maintained an insulin/relaxin-like overall fold, and the relaxin-3 B-chain adopted a conformation identical to that in native relaxin-3, confirming that the activity of R3/I5 can be directly related to its primary sequence. Furthermore, a truncation study was undertaken to ascertain the importance of the termini for structure and function. By using the knowledge generated from the structure-function relationship, a single-chain high affinity RXFP3 selective antagonist was developed.

In conclusion, this thesis has contributed to broaden the knowledge of the structure-function relationship of the relaxin ligands and the development of a selective RXFP3 antagonist, which is currently a drug lead for treatment of neurological disorders including stress and obesity.

Place, publisher, year, edition, pages
Växjö, Kalmar: Linneaus University Press, 2011
Series
Linnaeus University Dissertations ; 31/2011
Keywords
relaxin, insulin-like peptide, peptide hormone, peptide synthesis and NMR
National Category
Organic Chemistry
Research subject
Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-9793 (URN)978-91-86491-55-0 (ISBN)
Public defence
2011-01-28, N2007, Smålandsgatan 26B, Kalmar, 09:30 (English)
Opponent
Supervisors
Available from: 2010-12-21 Created: 2010-12-21 Last updated: 2017-04-18Bibliographically approved
Rosengren, K. J., Bathgate, R. A. .., Craik, D. J., Daly, N. L., Haugaard-Kedström (published under the name Haugaard-Jönsson), L. M., Hossain, M. A. & Wade, J. D. (2009). Structural insights into the function of relaxins. Paper presented at RELAXIN AND RELATED PEPTIDES: FIFTH INTERNATIONAL CONFERENCE. Annals of the New York Academy of Sciences, 1160, 20-26
Open this publication in new window or tab >>Structural insights into the function of relaxins
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2009 (English)In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 1160, p. 20-26Article in journal (Refereed) Published
Abstract [en]

The relaxin peptide hormones are members of the insulin superfamily and share a structural fold that is characterized by two peptide chains which are cross-braced by three disulfide bonds. On this framework, various amino acid side chains are presented, allowing specific interactions with different receptors. The relaxin receptors belong to two unrelated classes of G-protein-coupled receptors, but interestingly they are not selective for a single relaxin peptide. Relaxin-3, which is considered to be an extreme example of the relaxin family, can activate receptors from both classes and in fact interacts to some degree with all four receptors identified to date. To deduce how changes in the primary sequence can fine-tune the overall structure and thus the ability to interact with the various receptors, we have studied a range of relaxin-like peptides using solution nuclear magnetic resonance analysis. Three-dimensional structures of relaxin-3, insulin-like peptide 3 (INSL3), and INSL5 were determined and revealed a number of interesting features. All peptides showed a significant amount of line-broadening in certain regions, in particular around the intra-A-chain disulfide bond, suggesting that despite the disulfide bonds the fold is rather dynamic. Although the peptides share a common structural core there are significant differences, particularly around the termini. The structural data in combination with mutational studies provide valuable insights into the structure-activity relationships of relaxins.

National Category
Organic Chemistry
Research subject
Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-2093 (URN)10.1111/j.1749-6632.2009.03833.x (DOI)
Conference
RELAXIN AND RELATED PEPTIDES: FIFTH INTERNATIONAL CONFERENCE
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-04-18Bibliographically approved
Haugaard-Kedström (published under the name Haugaard-Jönsson), L. M., Hossain, M. A., Daly, N. L., Bathgate, R. A. .., Wade, J. D., Craik, D. J. & Rosengren, K. J. (2009). Structural Properties of Relaxin Chimeras: NMR Characterization of the R3/I5 Relaxin Peptide. Paper presented at RELAXIN AND RELATED PEPTIDES: FIFTH INTERNATIONAL CONFERENCE. Annals of the New York Academy of Sciences, 1160, 27-30
Open this publication in new window or tab >>Structural Properties of Relaxin Chimeras: NMR Characterization of the R3/I5 Relaxin Peptide
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2009 (English)In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 1160, p. 27-30Article in journal (Refereed) Published
Abstract [en]

Relaxin-3 interacts with high potency with three relaxin family peptide receptors (RXFP1, RXFP3, and RXFP4). Therefore, the development of selective agonist and antagonist analogs is important for in vivo studies characterizing the biological significance of the different receptor-ligand systems and for future pharmaceutical applications. Recent reports demonstrated that a peptide selective for RXFP3 and RXFP4 over RXFP1 can be generated by the combination of the relaxin-3 B chain with the A chain from insulin-like peptide 5 (INSL5), creating an R3/I5 chimera. We have used NMR spectroscopy to determine the three-dimensional structure of this peptide to gain structural insights into the consequences of combining chains from two different relaxins. The R3/I5 structure reveals a similar backbone conformation for the relaxin-3 B chain compared to native relaxin-3, and the INSL5 A chain displays a relaxin/insulin-like fold with two parallel helices. The findings indicate that binding and activation of RXFP3 and RXFP4 mainly require the B chain and that the A chain functions as structural support. RXFP1, however, demonstrates a more complex binding mechanism, involving both the A chain and the B chain. The creation of chimeras is a promising strategy for generating new structure-activity data on relaxins.

National Category
Organic Chemistry
Research subject
Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-2094 (URN)10.1111/j.1749-6632.2008.03805.x (DOI)
Conference
RELAXIN AND RELATED PEPTIDES: FIFTH INTERNATIONAL CONFERENCE
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-04-18Bibliographically approved
Haugaard-Kedström (published under the name Haugaard-Jönsson), L. M., Hossain, M. A., Daly, N. L., Craik, D. J., Wade, J. D. & Rosengren, K. J. (2009). Structure of the human insulin-like peptide 5 and characterization of conserved hydrogen bonds and electrostatic interactions within the relaxin framework. Biochemical Journal, 419, 619-627
Open this publication in new window or tab >>Structure of the human insulin-like peptide 5 and characterization of conserved hydrogen bonds and electrostatic interactions within the relaxin framework
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2009 (English)In: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 419, p. 619-627Article in journal (Refereed) Published
Abstract [en]

INSL5 (insulin-like peptide 5) is a two-chain peptide hormone related to insulin and relaxin. It was recently discovered through searches of expressed sequence tag databases and, although the fulfil biological significance of INSL5 is still being elucidated, high expression in peripheral tissues such as the colon, as well as in the brain and hypothalamus, suggests roles in gut contractility and neuroendocrine signalling. INSL5 activates the relaxin family peptide receptor 4 with high potency and appears to be the endogenous ligand for this receptor, on the basis of overlapping expression profiles and their apparent co-evolution. In the present Study, we have used solution-state NMR to characterize the three-dimensional structure of synthetic human INSL5. The structure reveals an insulin/relaxin-like fold with three helical segments that are braced by three disulfide bonds and enclose a hydrophobic core. Furthermore, we characterized in detail the hydrogen-bond network and electrostatic interactions between charged groups in INSL5 by NMR-monitored temperature and pH titrations and Undertook a comprehensive structural comparison with other members of the relaxin family, thus identifying the conserved structural features of the relaxin fold. The B-chain helix, which is the primary receptor-binding site of the relaxins, is longer in INSL5 than in its close relative relaxin-3. As this feature results in a different positioning of the receptor-activation domain Arg(B23) and Trp(B24), it may be an important contributor to the difference in biological activity observed for these two peptides. Overall, the structural Studies provide mechanistic insights into the receptor selectivity of this important family of hormones. 

National Category
Organic Chemistry
Research subject
Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-1953 (URN)10.1042/BJ20082353 (DOI)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-04-18Bibliographically approved
Göransson, U., Herrmann, A., Burman, R., Haugaard-Kedström (published under the name Haugaard-Jönsson), L. M. & Rosengren, K. J. (2009). The conserved Glu in the cyclotide cycloviolacin O2 has a key structural role. ChemBioChem (Print), 10(14), 2354-2360
Open this publication in new window or tab >>The conserved Glu in the cyclotide cycloviolacin O2 has a key structural role
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2009 (English)In: ChemBioChem (Print), ISSN 1439-4227, E-ISSN 1439-7633, Vol. 10, no 14, p. 2354-2360Article in journal (Refereed) Published
Abstract [en]

Cyclotides are a large family of plant peptides that are characterised by a head-to-tail circular backbone and three disulfide bonds that are arranged in a cystine knot. This unique structural feature, which is referred to as a cyclic cystine knot, gives the cyclotides remarkable stability against chemical and biological degradation. In addition to their natural function as insecticides for plant defence, the cyclotides have a range of bioactivities with pharmaceutical relevance, including cytotoxicity against cancer cell lines. A glutamic acid residue, aside from the invariable disulfide array, is the most conserved feature throughout the cyclotide family, and it has recently been shown to be crucial for biological activity. Here we have used solution-state NMR spectroscopy to determine the three-dimensional structures of the potent cytotoxic cyclotide cycloviolacin O2, and an inactive analogue in which this conserved glutamic acid has been methylated. The structures of the peptides show that the glutamic acid has a key structural role in coordinating a set of hydrogen bonds in native cycloviolacin O2; this interaction is disrupted in the methylated analogue. The proposed mechanism of action of cyclotides is membrane disruption and these results suggest that the glutamic acid is linked to cyclotide function by stabilising the structure to allow efficient aggregation in membranes, rather than in a direct interaction with a target receptor.

National Category
Organic Chemistry
Research subject
Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-2096 (URN)10.1002/cbic.200900342 (DOI)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-04-18Bibliographically approved
Haugaard-Kedström (published under the name Haugaard-Jönsson), L. M., Hossain, M. A., Daly, N. L., Bathgate, R. A. .., Wade, J. D., Craik, D. J. & Rosengren, J. (2008). Structure of the R3/I5 chimeric relaxin peptide, a selective GPCR135 and GPCR142 agonist. Journal of Biological Chemistry, 283(35), 23811-23818
Open this publication in new window or tab >>Structure of the R3/I5 chimeric relaxin peptide, a selective GPCR135 and GPCR142 agonist
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2008 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 283, no 35, p. 23811-23818Article in journal (Refereed) Published
Abstract [en]

The human relaxin family comprises seven peptide hormones with various biological functions mediated through interactions with G-protein-coupled receptors. Interestingly, among the hitherto characterized receptors there is no absolute selectivity toward their primary ligand. The most striking example of this is the relaxin family ancestor, relaxin-3, which is an agonist for three of the four currently known relaxin receptors: GPCR135, GPCR142, and LGR7. Relaxin-3 and its endogenous receptor GPCR135 are both expressed predominantly in the brain and have been linked to regulation of stress and feeding. However, to fully understand the role of relaxin-3 in neurological signaling, the development of selective GPCR135 agonists and antagonists for in vivo studies is crucial. Recent reports have demonstrated that such selective ligands can be achieved by making chimeric peptides comprising the relaxin-3 B-chain combined with the INSL5 A-chain. To obtain structural insights into the consequences of combining A-and B-chains from different relaxins we have determined the NMR solution structure of a human relaxin-3/INSL5 chimeric peptide. The structure reveals that the INSL5 A-chain adopts a conformation similar to the relaxin-3 A-chain, and thus has the ability to structurally support a native-like conformation of the relaxin-3 B-chain. These findings suggest that the decrease in activity at the LGR7 receptor seen for this peptide is a result of the removal of a secondary LGR7 binding site present in the relaxin-3 A-chain, rather than conformational changes in the primary B-chain receptor binding site. 

National Category
Medical and Health Sciences Organic Chemistry
Research subject
Natural Science, Biomedical Sciences; Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-1877 (URN)10.1074/jbc.M800489200 (DOI)
Available from: 2010-04-06 Created: 2010-04-06 Last updated: 2017-12-12Bibliographically approved
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