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Sewgobind NV, Albers S, Pieters RJ. Functions and Inhibition of Galectin-7, an Emerging Target in Cellular Pathophysiology. Biomolecules 2021; 11:1720. [PMID: 34827718 PMCID: PMC8615947 DOI: 10.3390/biom11111720] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 12/16/2022] Open
Abstract
Galectin-7 is a soluble unglycosylated lectin that is able to bind specifically to β-galactosides. It has been described to be involved in apoptosis, proliferation and differentiation, but also in cell adhesion and migration. Several disorders and diseases are discussed by covering the aforementioned biological processes. Structural features of galectin-7 are discussed as well as targeting the protein intracellularly or extracellularly. The exact molecular mechanisms that lie behind many biological processes involving galectin-7 are not known. It is therefore useful to come up with chemical probes or tools in order to obtain knowledge of the physiological processes. The objective of this review is to summarize the roles and functions of galectin-7 in the human body, providing reasons why it is necessary to design inhibitors for galectin-7, to give the reader structural insights and describe its current inhibitors.
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Affiliation(s)
| | | | - Roland J. Pieters
- Department of Chemical Biology & Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, P.O. Box 80082, NL-3508 TB Utrecht, The Netherlands; (N.V.S.); (S.A.)
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2
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Miller MC, Zheng Y, Suylen D, Ippel H, Cañada FJ, Berbís MA, Jiménez-Barbero J, Tai G, Gabius HJ, Mayo KH. Targeting the CRD F-face of Human Galectin-3 and Allosterically Modulating Glycan Binding by Angiostatic PTX008 and a Structurally Optimized Derivative. ChemMedChem 2020; 16:713-723. [PMID: 33156953 DOI: 10.1002/cmdc.202000742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/31/2020] [Indexed: 12/25/2022]
Abstract
Calix[4]arene PTX008 is an angiostatic agent that inhibits tumor growth in mice by binding to galectin-1, a β-galactoside-binding lectin. To assess the affinity profile of PTX008 for galectins, we used 15 N,1 H HSQC NMR spectroscopy to show that PTX008 also binds to galectin-3 (Gal-3), albeit more weakly. We identified the contact site for PTX008 on the F-face of the Gal-3 carbohydrate recognition domain. STD NMR revealed that the hydrophobic phenyl ring crown of the calixarene is the binding epitope. With this information, we performed molecular modeling of the complex to assist in improving the rather low affinity of PTX008 for Gal-3. By removing the N-dimethyl alkyl chain amide groups, we produced PTX013 whose reduced alkyl chain length and polar character led to an approximately eightfold stronger binding than PTX008. PTX013 also binds Gal-1 more strongly than PTX008, whereas neither interacts strongly, if at all, with Gal-7. In addition, PTX013, like PTX008, is an allosteric inhibitor of galectin binding to the canonical ligand lactose. This study broadens the scope for galectin targeting by calixarene-based compounds and opens the perspective for selective galectin blocking.
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Affiliation(s)
- Michelle C Miller
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Yi Zheng
- School of Life Science, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Dennis Suylen
- Department of Biochemistry and CARIM, Maastricht University, 6229HX, Maastricht, The Netherlands
| | - Hans Ippel
- Department of Biochemistry and CARIM, Maastricht University, 6229HX, Maastricht, The Netherlands
| | - F Javier Cañada
- NMR and Molecular Recognition Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - M Alvaro Berbís
- NMR and Molecular Recognition Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Jesús Jiménez-Barbero
- NMR and Molecular Recognition Group, Centro de Investigaciones Biológicas Margarita Salas (CSIC), C/Ramiro de Maeztu 9, 28040, Madrid, Spain.,CIC bioGUNE, Bizkaia Technological Park, Building 801 A, 48160, Derio, Spain.,Ikerbasque, Basque Foundation for Science, 28009, Bilbao, Spain
| | - Guihua Tai
- School of Life Science, Northeast Normal University, 130024, Changchun, People's Republic of China
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximillians-University, 80539, Munich, Germany
| | - Kevin H Mayo
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
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3
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López de Los Santos Y, Bernard DN, Egesborg P, Létourneau M, Lafortune C, Cuneo MJ, Urvoas A, Chatenet D, Mahy JP, St-Pierre Y, Ricoux R, Doucet N. Binding of a Soluble meso-Tetraarylporphyrin to Human Galectin-7 Induces Oligomerization and Modulates Its Pro-Apoptotic Activity. Biochemistry 2020; 59:4591-4600. [PMID: 33231438 DOI: 10.1021/acs.biochem.0c00736] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The selective targeting of protein-protein interactions remains a significant determinant for the proper modulation and regulation of cell apoptosis. Prototypic galectins such as human galectin-7 (GAL-7) are characterized by their ability to form homodimers that control the molecular fate of a cell by mediating subtle yet critical glycan-dependent interactions between pro- and anti-apoptotic molecular partners. Altering the structural architecture of GAL-7 can therefore result in resistance to apoptosis in various human cancer cells, further illustrating its importance in cell survival. In this study, we used a combination of biophysical and cellular assays to illustrate that binding of a water-soluble meso-tetraarylporphyrin molecule to GAL-7 induces protein oligomerization and modulation of GAL-7-induced apoptosis in human Jurkat T cells. Our results suggest that the integrity of the GAL-7 homodimer architecture is essential for its molecular function, in addition to providing an interesting porphyrin binding modulator for controlling apoptosis in mammalian cells.
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Affiliation(s)
- Yossef López de Los Santos
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - David N Bernard
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - Philippe Egesborg
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - Myriam Létourneau
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - Clara Lafortune
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - Matthew J Cuneo
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, United States
| | - Agathe Urvoas
- Institut de biologie intégrative de la cellule (I2BC), CNRS, Université Paris-Saclay, 91190 Orsay, France
| | - David Chatenet
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - Jean-Pierre Mahy
- Laboratoire de chimie bioorganique et bioinorganique, Institut de chimie moléculaire et des matériaux d'Orsay (ICMMO), CNRS, Université Paris-Saclay, 91190 Orsay, France
| | - Yves St-Pierre
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada
| | - Rémy Ricoux
- Laboratoire de chimie bioorganique et bioinorganique, Institut de chimie moléculaire et des matériaux d'Orsay (ICMMO), CNRS, Université Paris-Saclay, 91190 Orsay, France
| | - Nicolas Doucet
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, Laval, QC H7V 1B7, Canada.,PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Quebec City, QC G1V 0A6, Canada
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4
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Miller MC, Cai C, Wichapong K, Bhaduri S, Pohl NLB, Linhardt RJ, Gabius HJ, Mayo KH. Structural insight into the binding of human galectins to corneal keratan sulfate, its desulfated form and related saccharides. Sci Rep 2020; 10:15708. [PMID: 32973213 PMCID: PMC7515912 DOI: 10.1038/s41598-020-72645-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/11/2020] [Indexed: 02/08/2023] Open
Abstract
Glycosaminoglycan chains of keratan sulfate proteoglycans appear to be physiologically significant by pairing with tissue lectins. Here, we used NMR spectroscopy and molecular dynamics (MD) simulations to characterize interactions of corneal keratan sulfate (KS), its desulfated form, as well as di-, tetra- (N-acetyllactosamine and lacto-N-tetraose) and octasaccharides with adhesion/growth-regulatory galectins, in particular galectin-3 (Gal-3). The KS contact region involves the lectin canonical binding site, with estimated KD values in the low µM range and stoichiometry of ~ 8 to ~ 20 galectin molecules binding per polysaccharide chain. Compared to Gal-3, the affinity to Gal-7 is relatively low, signaling preferences among galectins. The importance of the sulfate groups was delineated by using desulfated analogs that exhibit relatively reduced affinity. Binding studies with two related di- and tetrasaccharides revealed a similar decrease that underscores affinity enhancement by repetitive arrangement of disaccharide units. MD-based binding energies of KS oligosaccharide-loaded galectins support experimental data on Gal-3 and -7, and extend the scope of KS binding to Gal-1 and -9N. Overall, our results provide strong incentive to further probe the relevance of molecular recognition of KS by galectins in terms of physiological processes in situ, e.g. maintaining integrity of mucosal barriers, intermolecular (lattice-like) gluing within the extracellular meshwork or synaptogenesis.
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Affiliation(s)
- Michelle C Miller
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Chao Cai
- Biocatalysis and Metabolic Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Kanin Wichapong
- Department of Biochemistry and the Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Sayantan Bhaduri
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Nicola L B Pohl
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Robert J Linhardt
- Biocatalysis and Metabolic Engineering, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximillians-University Munich, 80539, Munich, Germany
| | - Kevin H Mayo
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA.
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5
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Miller MC, Nesmelova IV, Daragan VA, Ippel H, Michalak M, Dregni A, Kaltner H, Kopitz J, Gabius HJ, Mayo KH. Pro4 prolyl peptide bond isomerization in human galectin-7 modulates the monomer-dimer equilibrum to affect function. Biochem J 2020; 477:3147-3165. [PMID: 32766716 PMCID: PMC7473712 DOI: 10.1042/bcj20200499] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 02/06/2023]
Abstract
Human galectin-7 (Gal-7; also termed p53-induced gene 1 product) is a multifunctional effector by productive pairing with distinct glycoconjugates and protein counter-receptors in the cytoplasm and nucleus, as well as on the cell surface. Its structural analysis by NMR spectroscopy detected doubling of a set of particular resonances, an indicator of Gal-7 existing in two conformational states in slow exchange on the chemical shift time scale. Structural positioning of this set of amino acids around the P4 residue and loss of this phenomenon in the bioactive P4L mutant indicated cis-trans isomerization at this site. Respective resonance assignments confirmed our proposal of two Gal-7 conformers. Mapping hydrogen bonds and considering van der Waals interactions in molecular dynamics simulations revealed a structural difference for the N-terminal peptide, with the trans-state being more exposed to solvent and more mobile than the cis-state. Affinity for lactose or glycan-inhibitable neuroblastoma cell surface contact formation was not affected, because both conformers associated with an overall increase in order parameters (S2). At low µM concentrations, homodimer dissociation is more favored for the cis-state of the protein than its trans-state. These findings give direction to mapping binding sites for protein counter-receptors of Gal-7, such as Bcl-2, JNK1, p53 or Smad3, and to run functional assays at low concentration to test the hypothesis that this isomerization process provides a (patho)physiologically important molecular switch for Gal-7.
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Affiliation(s)
- Michelle C. Miller
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Irina V. Nesmelova
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Vladimir A. Daragan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Hans Ippel
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
- Department of Biochemistry, CARIM, University of Maastricht, Maastricht, The Netherlands
| | - Malwina Michalak
- Department of Applied Tumor Biology, Institute of Pathology, Medical School of the Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Aurelio Dregni
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
| | - Herbert Kaltner
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximillians-University Munich, Munich, Germany
| | - Jürgen Kopitz
- Department of Applied Tumor Biology, Institute of Pathology, Medical School of the Ruprecht-Karls-University Heidelberg, Heidelberg, Germany
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximillians-University Munich, Munich, Germany
| | - Kevin H. Mayo
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 U.S.A
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6
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Adhesion/growth-regulatory galectins tested in combination: evidence for formation of hybrids as heterodimers. Biochem J 2018; 475:1003-1018. [PMID: 29321242 DOI: 10.1042/bcj20170658] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/22/2017] [Accepted: 01/07/2018] [Indexed: 12/14/2022]
Abstract
The delineation of the physiological significance of protein (lectin)-glycan recognition and the structural analysis of individual lectins have directed our attention to studying them in combination. In this report, we tested the hypothesis of hybrid formation by using binary mixtures of homodimeric galectin-1 and -7 as well as a proteolytically truncated version of chimera-type galectin-3. Initial supportive evidence is provided by affinity chromatography using resin-presented galectin-7. Intriguingly, the extent of cell binding by cross-linking of surface counter-receptor increased significantly for monomeric galectin-3 form by the presence of galectin-1 or -7. Pulsed-field gradient NMR (nuclear magnetic resonance) diffusion measurements on these galectin mixtures indicated formation of heterodimers as opposed to larger oligomers. 15N-1H heteronuclear single quantum coherence NMR spectroscopy and molecular dynamics simulations allowed us to delineate how different galectins interact in the heterodimer. The possibility of domain exchange between galectins introduces a new concept for understanding the spectrum of their functionality, particularly when these effector molecules are spatially and temporally co-expressed as found in vivo.
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7
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Lactose Binding Induces Opposing Dynamics Changes in Human Galectins Revealed by NMR-Based Hydrogen-Deuterium Exchange. Molecules 2017; 22:molecules22081357. [PMID: 28813004 PMCID: PMC6152064 DOI: 10.3390/molecules22081357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 11/17/2022] Open
Abstract
Galectins are β-galactoside-binding proteins implicated in a myriad of biological functions. Despite their highly conserved carbohydrate binding motifs with essentially identical structures, their affinities for lactose, a common galectin inhibitor, vary significantly. Here, we aimed to examine the molecular basis of differential lactose affinities amongst galectins using solution-based techniques. Consistent dissociation constants of lactose binding were derived from nuclear magnetic resonance (NMR) spectroscopy, intrinsic tryptophan fluorescence, isothermal titration calorimetry and bio-layer interferometry for human galectin-1 (hGal1), galectin-7 (hGal7), and the N-terminal and C-terminal domains of galectin-8 (hGal8NTD and hGal8CTD, respectively). Furthermore, the dissociation rates of lactose binding were extracted from NMR lineshape analyses. Structural mapping of chemical shift perturbations revealed long-range perturbations upon lactose binding for hGal1 and hGal8NTD. We further demonstrated using the NMR-based hydrogen–deuterium exchange (HDX) that lactose binding increases the exchange rates of residues located on the opposite side of the ligand-binding pocket for hGal1 and hGal8NTD, indicative of allostery. Additionally, lactose binding induces significant stabilisation of hGal8CTD across the entire domain. Our results suggested that lactose binding reduced the internal dynamics of hGal8CTD on a very slow timescale (minutes and slower) at the expense of reduced binding affinity due to the unfavourable loss of conformational entropy.
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8
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Hsieh TJ, Lin HY, Tu Z, Lin TC, Wu SC, Tseng YY, Liu FT, Hsu STD, Lin CH. Dual thio-digalactoside-binding modes of human galectins as the structural basis for the design of potent and selective inhibitors. Sci Rep 2016; 6:29457. [PMID: 27416897 PMCID: PMC4945863 DOI: 10.1038/srep29457] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/17/2016] [Indexed: 12/24/2022] Open
Abstract
Human galectins are promising targets for cancer immunotherapeutic and fibrotic disease-related drugs. We report herein the binding interactions of three thio-digalactosides (TDGs) including TDG itself, TD139 (3,3'-deoxy-3,3'-bis-(4-[m-fluorophenyl]-1H-1,2,3-triazol-1-yl)-thio-digalactoside, recently approved for the treatment of idiopathic pulmonary fibrosis), and TAZTDG (3-deoxy-3-(4-[m-fluorophenyl]-1H-1,2,3-triazol-1-yl)-thio-digalactoside) with human galectins-1, -3 and -7 as assessed by X-ray crystallography, isothermal titration calorimetry and NMR spectroscopy. Five binding subsites (A-E) make up the carbohydrate-recognition domains of these galectins. We identified novel interactions between an arginine within subsite E of the galectins and an arene group in the ligands. In addition to the interactions contributed by the galactosyl sugar residues bound at subsites C and D, the fluorophenyl group of TAZTDG preferentially bound to subsite B in galectin-3, whereas the same group favored binding at subsite E in galectins-1 and -7. The characterised dual binding modes demonstrate how binding potency, reported as decreased Kd values of the TDG inhibitors from μM to nM, is improved and also offer insights to development of selective inhibitors for individual galectins.
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Affiliation(s)
- Tung-Ju Hsieh
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Hsien-Ya Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan.,Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Zhijay Tu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Ting-Chien Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan.,Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Shang-Chuen Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Yu-Yao Tseng
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan
| | - Fu-Tong Liu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Shang-Te Danny Hsu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan.,Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan.,The Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan
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Ippel H, Miller MC, Berbís MA, Suylen D, André S, Hackeng TM, Cañada FJ, Weber C, Gabius HJ, Jiménez-Barbero J, Mayo KH. (1)H, (13)C, and (15)N backbone and side-chain chemical shift assignments for the 36 proline-containing, full length 29 kDa human chimera-type galectin-3. BIOMOLECULAR NMR ASSIGNMENTS 2015; 9:59-63. [PMID: 24504927 DOI: 10.1007/s12104-014-9545-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/27/2014] [Indexed: 06/03/2023]
Abstract
Galectin-3, an adhesion/growth regulatory lectin, has a unique trimodular design consisting of the canonical carbohydrate recognition domain, a collagen-like tandem-repeat section, and an N-terminal peptide with two sites for Ser phosphorylation. Structural characterization of the full length protein with its non-lectin part (115 of 250 residues total) will help understand the multi functionality of this potent cellular effector. Here, we report (1)H, (13)C, and (15)N chemical shift assignments as determined by heteronuclear NMR spectroscopy .
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Affiliation(s)
- Hans Ippel
- Department of Biochemistry and CARIM, University of Maastricht, Maastricht, The Netherlands
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10
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Thio- and selenoglycosides as ligands for biomedically relevant lectins: valency-activity correlations for benzene-based dithiogalactoside clusters and first assessment for (di)selenodigalactosides. Bioorg Med Chem Lett 2014; 25:931-5. [PMID: 25599835 DOI: 10.1016/j.bmcl.2014.12.049] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/10/2014] [Accepted: 12/12/2014] [Indexed: 01/26/2023]
Abstract
Substitution of the oxygen atom in the glycosidic linkage by a disulfide bond or by selenium makes the resulting glycoside resistant to hydrolysis. To clarify the consequences for affinity to lectins we prepared benzene-based mono- to trivalent dithiogalactosides. Inhibitory capacity increased with valency for a plant toxin, the synthetic compounds potently blocking its binding to a lactose-presenting matrix and to cells. Human galectins were much less sensitive to the disulfides than the toxin. This differential response constitutes a beneficial effect to avoid cross-reactivity in vivo. Symmetrical selenodigalactoside and diselenodigalactoside were prepared and similarly tested. Both compounds proved rather equally bioactive for the toxin, graded activity was measured for human galectins. This result directs attention to further studies to relate Se-dependent alterations in bond angle and length as well as van der Waals radius to binding properties of selenoglycosides to biomedically relevant lectins.
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11
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Ramaswamy S, Sleiman MH, Masuyer G, Arbez-Gindre C, Micha-Screttas M, Calogeropoulou T, Steele BR, Acharya KR. Structural basis of multivalent galactose-based dendrimer recognition by human galectin-7. FEBS J 2014; 282:372-87. [PMID: 25367374 DOI: 10.1111/febs.13140] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 10/03/2014] [Accepted: 10/30/2014] [Indexed: 12/30/2022]
Abstract
Galectins are evolutionarily conserved and ubiquitously present animal lectins with a high affinity for β-galactose-containing oligosaccharides. To date, 15 mammalian galectins have been identified. Their involvement in cell-cell and cell-matrix interactions has highlighted their importance in signal transduction and other intracellular processes. Human galectin-7 (hGal-7) is a 15 kDa proto type galectin that forms a dimer in solution and its involvement in the stimulation and development of tumour growth has been reported. Previously, we reported the crystal structure of hGal-7 and its complex with galactose and lactose which provided insight into its molecular recognition and detailed interactions. Here, we present newly obtained high-resolution structural data on carbohydrate-based dendrons in complex with hGal-7. Our crystallographic data reveal how multivalent ligands interact with and form cross-links with these galectin molecules. Understanding how these dendrimeric compounds interact with hGal-7 would help in the design of new tools to investigate the recognition of carbohydrates by lectins.
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Affiliation(s)
- Sneha Ramaswamy
- Department of Biology and Biochemistry, University of Bath, UK
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12
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Kaltner H, Raschta AS, Manning JC, Gabius HJ. Copy-number variation of functional galectin genes: studying animal galectin-7 (p53-induced gene 1 in man) and tandem-repeat-type galectins-4 and -9. Glycobiology 2013; 23:1152-63. [PMID: 23840039 DOI: 10.1093/glycob/cwt052] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Galectins are potent adhesion/growth-regulatory effectors with characteristic expression profiles. Understanding the molecular basis of gene regulation in each case requires detailed information on copy number of genes and sequence(s) of their promoter(s). Our report reveals plasticity in this respect between galectins and species. We here describe occurrence of a two-gene constellation for human galectin (Gal)-7 and define current extent of promoter-sequence divergence. Interestingly, cross-species genome analyses also detected single-copy display. Because the regulatory potential will then be different, extrapolations of expression profiles are precluded between respective species pairs. Gal-4 coding in chromosomal vicinity was found to be confined to one gene, whereas copy-number variation also applied to Gal-9. The example of rat Gal-9 teaches the lesson that the presence of multiple bands in Southern blotting despite a single-copy gene constellation is attributable to two pseudogenes. The documented copy-number variability should thus be taken into consideration when studying regulation of galectin genes, in a species and in comparison between species.
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Affiliation(s)
- Herbert Kaltner
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Veterinärstr. 13, 80539 München, Germany
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Ermakova E, Miller MC, Nesmelova IV, López-Merino L, Berbís MA, Nesmelov Y, Tkachev YV, Lagartera L, Daragan VA, André S, Cañada FJ, Jiménez-Barbero J, Solís D, Gabius HJ, Mayo KH. Lactose binding to human galectin-7 (p53-induced gene 1) induces long-range effects through the protein resulting in increased dimer stability and evidence for positive cooperativity. Glycobiology 2013; 23:508-23. [PMID: 23376190 DOI: 10.1093/glycob/cwt005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The product of p53-induced gene 1 is a member of the galectin family, i.e., galectin-7 (Gal-7). To move beyond structural data by X-ray diffraction, we initiated the study of the lectin by nuclear magnetic resonance (NMR) and circular dichroism spectroscopies, and molecular dynamics (MD) simulations. In concert, our results indicate that lactose binding to human Gal-7 induces long-range effects (minor conformational shifts and changes in structural dynamics) throughout the protein that result in stabilization of the dimer state, with evidence for positive cooperativity. Monte Carlo fits of (15)N-Gal-7 HSQC titrations with lactose using a two-site model yield K1 = 0.9 ± 0.6 × 10(3) M(-1) and K2 = 3.4 ± 0.8 × 10(3) M(-1). Ligand binding-induced stabilization of the Gal-7 dimer was supported by several lines of evidence: MD-based calculations of interaction energies between ligand-loaded and ligand-free states, gel filtration data and hetero-FRET spectroscopy that indicate a highly reduced tendency for dimer dissociation in the presence of lactose, CD-based thermal denaturation showing that the transition temperature of the lectin is significantly increased in the presence of lactose, and saturation transfer difference (STD) NMR using a molecular probe of the monomer state whose presence is diminished in the presence of lactose. MD simulations with the half-loaded ligand-bound state also provided insight into how allosteric signaling may occur. Overall, our results reveal long-range effects on Gal-7 structure and dynamics, which factor into entropic contributions to ligand binding and allow further comparisons with other members of the galectin family.
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Affiliation(s)
- Elena Ermakova
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 6-155 Jackson Hall, 321 Church Street, Minneapolis, MN 55455, USA
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