title: Quaternary solution structures of galectins-1, -3, and -7.
abstract: Galectins are a growing family of animal lectins with functions in growth regulation and cell adhesion that bind beta-Gal residues in oligosaccharides. Evidence indicates that some of the biological properties of galectins are due to their cross-linking activities with multivalent glycoconjugate receptors. Therefore determination of the quaternary solution structures of these proteins is important in understanding their structure-function properties. The present study reports analytical sedimentation velocity and equilibrium data for galectins-1, -3, and -7 in the absence and presence of bound LacNAc, the natural ligand epitope. Galectin-1 from bovine heart and recombinant human galectin-7 were found to be stable dimers by both methods. In contrast, recombinant murine galectin-3, as well as its proteolytical derived C-terminal domain, are predominantly monomeric. The presence of LacNAc at concentrations sufficient to fully saturate the proteins had no significant effect on either the weight average molecular weight determined by sedimentation equilibrium or the hydrodynamic properties determined from sedimentation velocity experiments. These results show that binding of a monovalent ligand does not affect oligomerization of these galectins.
authors.affiliation: Department of Biochemistry, and Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Morris
authors.forename: Nisar
authors.initials: N
authors.lastname: Ahmad
authors.forename: Sabine
authors.initials: S
authors.lastname: André
authors.forename: Herbert
authors.initials: H
authors.lastname: Kaltner
authors.forename: Hans-J
authors.initials: HJ
authors.lastname: Gabius
authors.forename: Michael
authors.initials: M
authors.lastname: Brenowitz
authors.forename: Fred
authors.initials: F
authors.lastname: Brewer
mesh_terms: D000818:Animals; D002417:Cattle; D037483:Galectin 1 / Q000737:chemistry*; D037502:Galectin 3 / Q000737:chemistry*; D037161:Galectins / Q000737:chemistry*; D006801:Humans; D051379:Mice; D020836:Protein Structure, Quaternary; D012996:Solutions / Q000737:chemistry; D013057:Spectrum Analysis; D014461:Ultracentrifugation
chemical_list: D037483:Galectin 1; D037502:Galectin 3; D037161:Galectins; C092525:LGALS7 protein, human; C490487:Lgals7 protein, mouse; D012996:Solutions