Y. Fujimura et al., Antigen binding of an ovomucoid-specific antibody is affected by a carbohydrate chain located on the light chain variable region, BIOS BIOT B, 64(11), 2000, pp. 2298-2305
We cloned the variable regions of heavy and light chain genes of an anti-ov
omucoid monoclonal antibody (MAb-OM21) produced by the mouse hybridoma cell
line OM21. DNA sequence analysis showed that the light chain of the MAb-OM
21 has only one potential N-glycosylation consensus sequence in the complem
entarity determining region 2 of the light chain. To find whether carbohydr
ate chains are located on the light chain, we assayed for the size of the l
ight chain, after treatment with N-glycosidase, by western blotting, and al
so detection of the carbohydrate chains on the light chain was done using t
he 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 l
ight chain, we produced carbohydrate variant antibodies by N-deglycosylatio
n using glycosidase or by expressing the antibody from different host cells
. The N-deglycosylated variant antibody has greater antigen binding, and th
e antibody produced from the different host cells showed a reduced antigen
binding activity and acquired the ability to react to ovalbumin. These resu
lts suggest that antigen binding of the ovomucoid specific antibody MAb-OM2
1 can be affected by the carbohydrate chain on the light chain variable reg
ion.