title: Partial identification by site-directed mutagenesis of a cell growth inhibitory site on the human galectin-1 molecule.
abstract: BACKGROUND
  Previous work, by us and others, has shown that mammalian galectins-1 have a growth-inhibitory activity for mammalian cells which is apparently independent of their beta-galactoside binding site.
  
  
  RESULTS
  We have made recombinant human galectin-1 as a bacterial fusion protein with an N-terminal hexahistidine tag. This protein displays both haemagglutination and growth-inhibitory activities, even in the presence of the hexahistidine tag. Site-directed mutagenesis of this protein has confirmed the independent nature of the protein sites responsible for the two biological activities. Mutant proteins were created, which displayed each activity in the absence of the other.
  
  
  CONCLUSIONS
  Human galectin-1 possesses a growth-inhibitory site, which is not part of the beta-galactoside binding site. A surface loop, comprising amino acid residues 25-30, and joining two internal beta-strands, forms part of the growth-inhibitory site. This region is relatively close to the N-terminus of the protein, and N-terminal substitutions or extensions also affect growth-inhibitory activity. Further experiments will be necessary to fully define this site.
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand. k.scott@auckland.ac.nz
authors.forename: Ken
authors.initials: K
authors.lastname: Scott
authors.forename: Jialiang
authors.initials: J
authors.lastname: Zhang
mesh_terms: D002455:Cell Division / Q000235:genetics; D002478:Cells, Cultured; D005347:Fibroblasts / Q000737:chemistry / Q000378:metabolism; D037483:Galectin 1 / Q000737:chemistry* / Q000235:genetics*; D006131:Growth Inhibitors / Q000235:genetics*; D006801:Humans; D016297:Mutagenesis, Site-Directed / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics
chemical_list: D037483:Galectin 1; D006131:Growth Inhibitors; D011993:Recombinant Fusion Proteins