Antibody variable region glycosylation: position effects on antigen binding and carbohydrate structure

EMBO J. 1991 Oct;10(10):2717-23.


The presence of N-linked carbohydrate at Asn58 in the VH of the antigen binding site of an antibody specific for alpha(1----6)dextran (TKC3.2.2) increases its affinity for dextran 10- to 50-fold. Site-directed mutagenesis has now been used to create novel carbohydrate addition sequences in the CDR2 of a non-glycosylated anti-dextran at Asn54 (TST2) and Asn60 (TSU7). These antibodies are glycosylated and the carbohydrates are accessible for lectin binding. The amino acid change in TSU7 (Lys62----Thr62) decreases the affinity for antigen; however, glycosylation of TSU7 increased its affinity for antigen 3-fold, less than the greater than 10-fold increase in affinity seen for glycosylated TKC3.2.2. The difference in impact of glycosylation could result either from the position of the carbohydrate or from its structure; unlike the other antibodies, TSU7 attaches a high mannose, rather than complex, carbohydrate in CDR2. In contrast, glycosylation of TST2 at amino acid 54 inhibits dextran binding. Thus slight changes in the position of the N-linked carbohydrate in the CDR2 of this antibody result in substantially different effects on antigen binding. Unlike what was observed for the anti-dextrans, a carbohydrate addition site placed in a similar position in an anti-dansyl is not utilized.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen-Antibody Reactions*
  • Carbohydrate Conformation
  • Carbohydrate Metabolism*
  • Cell Line
  • Concanavalin A / metabolism
  • Dextrans / immunology
  • Electrophoresis, Polyacrylamide Gel
  • Glycosylation
  • Hydrolysis
  • Immunoglobulin Fab Fragments / metabolism
  • Immunoglobulin Variable Region / genetics
  • Immunoglobulin Variable Region / metabolism*
  • Lectins / metabolism
  • Mice
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Transfection


  • Dextrans
  • Immunoglobulin Fab Fragments
  • Immunoglobulin Variable Region
  • Lectins
  • Concanavalin A