Antigen binding of an ovomucoid-specific antibody is affected by a carbohydrate chain located on the light chain variable region.
We cloned the variable regions of heavy and light chain genes of an anti-ovomucoid monoclonal antibody (MAb-OM21) produced by the mouse hybridoma cell line OM21. DNA sequence analysis showed that the light chain of the MAb-OM21 has only one potential N-glycosylation consensus sequence in the complementarity determining region 2 of the light chain. To find whether carbohydrate chains are located on the light chain, we assayed for the size of the light chain, after treatment with N-glycosidase, by western blotting, and also detection of the carbohydrate chains on the light chain was done using the lectin blot assay. A N-linked carbohydrate chain has been shown to bind to the light chain. To clarify the role of this carbohydrate chain in the light chain, we produced carbohydrate variant antibodies by N-deglycosylation using glycosidase or by expressing the antibody from different host cells. The N-deglycosylated variant antibody has greater antigen binding, and the antibody produced from the different host cells showed a reduced antigen binding activity and acquired the ability to react to ovalbumin. These results suggest that antigen binding of the ovomucoid specific antibody MAb-OM21 can be affected by the carbohydrate chain on the light chain variable region.
Fujimura
Y
Y
Division of Bioresources and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan.
Tachibana
H
H
Eto
N
N
Yamada
K
K
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000737:chemistry / Q000276:immunology; D000937:Antigen-Antibody Reactions; D000941:Antigens; D001483:Base Sequence; D016466:CHO Cells; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000276:immunology*; D003001:Cloning, Molecular; D006224:Cricetinae; D006031:Glycosylation; D006825:Hybridomas; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D010059:Ovomucin / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000941:Antigens; D002241:Carbohydrates; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D010059:Ovomucin