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.

MATERIALS AND 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.

CONCLUSION:

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: Saharuddin Bin Mohamad, Hideko Nagasawa, Yoshihiro Uto, Hitoshi Hori
• Journal: Anticancer research (Anticancer Res) 2002 Nov-Dec Vol. 22 Issue 6C Pg. 4297-300 ISSN: 0250-7005 [Print] Greece
• PMID: 12553073 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Macrophage-Activating Factors
• Vitamin D-Binding Protein
• vitamin D-binding protein-macrophage activating factor
• Superoxides
• Neuraminidase
• beta-Galactosidase

Topics

• Animals
• Blotting, Western
• Chromatography, Affinity
• Humans
• Macrophage Activation (drug effects)
• Macrophage-Activating Factors (chemistry, metabolism, pharmacology)
• Macrophages, Peritoneal (drug effects, metabolism)
• Mice
• Neuraminidase (chemistry, metabolism)
• Superoxides (metabolism)
• Vitamin D-Binding Protein (blood, chemistry, isolation & purification, metabolism, pharmacology)
• beta-Galactosidase (chemistry, metabolism)