title: Preparation of Gc protein-derived macrophage activating factor (GcMAF) and its structural characterization and biological activities.
abstract: BACKGROUND
  Gc protein has been reported to be a precursor of Gc protein-derived macrophage activation factor (GcMAF) in the inflammation-primed macrophage activation cascade. An inducible beta-galactosidase of B cells and neuraminidase of T cells convert Gc protein to GcMAF.
  
  
  METHODS
  Gc protein from human serum was purified using 25(OH)D3 affinity column chromatography and modified to GcMAF using immobilized glycosidases (beta-galactosidase and neuraminidase) The sugar moiety structure of GcMAF was characterized by lectin blotting by Helix pomatia agglutinin. The biological activities of GcMAF were evaluated by a superoxide generation assay and a phagocytosis assay.
  
  
  RESULTS
  We successfully purified Gc protein from human serum. GcMAF was detected by lectin blotting and showed a high biological activity.
  
  
  CONCLUSIONS
  Our results support the importance of the terminal N-acetylgalactosamine moiety in the GcMAF-mediated macrophage activation cascade, and the existence of constitutive GcMAF in human serum. These preliminary data are important for designing small molecular GcMAF mimics.
authors.affiliation: Department of Biological Science and Technology, Faculty of Engineering, University of Tokushima, Minamijyosanjimacho-2, Tokushima, 770-8506 Japan.
authors.forename: Saharuddin Bin
authors.initials: SB
authors.lastname: Mohamad
authors.forename: Hideko
authors.initials: H
authors.lastname: Nagasawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Uto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hori
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002846:Chromatography, Affinity; D006801:Humans; D008262:Macrophage Activation / Q000187:drug effects; D016215:Macrophage-Activating Factors / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009439:Neuraminidase / Q000737:chemistry / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014809:Vitamin D-Binding Protein / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001616:beta-Galactosidase / Q000737:chemistry / Q000378:metabolism
chemical_list: D016215:Macrophage-Activating Factors; D014809:Vitamin D-Binding Protein; C101908:vitamin D-binding protein-macrophage activating factor; D013481:Superoxides; D009439:Neuraminidase; D001616:beta-Galactosidase