title: Cross-link formation between mutant galectins of Caenorhabditis elegans with a substituted cysteine residue and asialofetuin via a photoactivatable bifunctional reagent.
abstract: LEC-1 is the first tandem repeat-type galectin isolated from an animal system; this galectin has two carbohydrate recognition domains in a single polypeptide chain. Because its two lectin domains have different sugar-binding profiles, these domains are thought to interact with different carbohydrate ligands. In our previous study, we showed that a mutant of LEC-1 in which a cysteine residue was introduced at a unique position in the N-terminal lectin domain (Nh) can be cross-linked with a model glycoprotein ligand, bovine asialofetuin, by using a bifunctional photoactivatable cross-linking reagent, benzophenone-4-maleimide. In the present work, we applied the same procedure to the C-terminal lectin domain (Ch) of LEC-1. Cross-linked products were formed in the cases of two mutants in which a cysteine residue was introduced at Lys¹⁷⁷ and Ser²⁶⁸, respectively. This method is very useful for capturing and assigning endogenous ligand glycoconjugates with relatively low affinities to each carbohydrate recognition domain of the whole tandem repeat-type galectin molecule.
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Tamura
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Takamasa
authors.initials: T
authors.lastname: Nonaka
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Kasai
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Arata
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001212:Asialoglycoproteins / Q000737:chemistry*; D001577:Benzophenones / Q000737:chemistry; D017173:Caenorhabditis elegans / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics; D002417:Cattle; D003432:Cross-Linking Reagents / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D060748:Fetuins; D037161:Galectins / Q000737:chemistry* / Q000235:genetics; D006001:Glycoconjugates / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D008301:Maleimides / Q000737:chemistry; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry; D055668:Photochemical Processes; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000737:chemistry*
chemical_list: D001212:Asialoglycoproteins; D001577:Benzophenones; D029742:Caenorhabditis elegans Proteins; D003432:Cross-Linking Reagents; D060748:Fetuins; D037161:Galectins; D006001:Glycoconjugates; C525184:Lec-1 protein, C elegans; D008024:Ligands; D008301:Maleimides; D050505:Mutant Proteins; D011994:Recombinant Proteins; D000509:alpha-Fetoproteins; C017029:asialofetuin; C046109:benzophenone-4-maleimide; D003545:Cysteine