The synthesis of deoxy-α-Gal epitope derivatives for the evaluation of an anti-α-Gal antibody binding
作者:Adam J. Janczuk、Wei Zhang、Peter R. Andreana、Joshua Warrick、Peng G. Wang
DOI:10.1016/s0008-6215(02)00159-3
日期:2002.8
alpha-Gal epitopes (also termed as alpha-Gal) are carbohydrate structures bearing the alpha-D-Gal-(1 --> 3)-beta-D-Gal terminus 1 and are known to be the antigen responsible for antibody-mediated hyperacute rejection in xenotransplantation. Terminal 2-, 3-, 4-, and 6-deoxy-Gal derivatives of alpha-Gal were synthesized. Inhibition ELISA using mouse laminin was established to determine the binding affinity of the synthesized alpha-Gal derivatives. 4-Deoxy-alpha-Gal derivative 7 showed a significant reduction in antibody recognition. The IC50 value was 15-fold poorer than the standard alpha-Gal epitopes alpha-D-Gal-(1 --> 3)-beta-D-Gal-(1 --> 4)-beta-D-Glc-NHAc (39) and alpha-D-Gal-(1 --> 3)-beta-D-Gal-(1 -- 4)-beta-D-Glc-OBn (40). A similar observation was seen with 2-deoxy-alpha-Gal derivative 5, whose IC50 value was nearly tenfold higher than the standards. Interestingly, substitution at the terminal 3-position resulted in only a fourfold decrease in antibody recognition, suggesting a possible point of future derivation. Finally, 6-deoxy-alpha-Gal derivative 8 exhibited similar antibody recognition to both alpha-Gal epitope 39 and alpha-Gal epitope 40. This strongly suggests that derivatization at the 6-position can be accomplished without loss of antibody recognition. These findings can be utilized for the future design of other alpha-Gal derivatives. (C) 2002 Elsevier Science Ltd. All rights reserved.