ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
In a previous study, we noticed an unexpected reaction of an antithyrotropin receptor ectodomain (ETSHR)-reactive monoclonal antibody, A10, with α1-antitrypsin (antitrypsin). Presently, we decided to probe the structural basis of this cross-reactivity. Recombinant ETSHR, antitrypsin, synthetic peptides corresponding to the region of similarity in these proteins (EEDFRV and EEDFHV, respectively) and a set of peptides related to this region, N- and C-terminally elongated, were used in the study. Comparing the values of the dissociation constants, we found that the affinity of peptides corresponding to the region of similarity to monoclonal antibody A10 was the same in spite of a difference in one residue (R 38 in ETSHR and H 209 in antitrypsin), whereas a change of E 206 to R in antitrypsin-related peptide dramatically decreased the affinity. The whole binding site of A10 in ETSHR as well as in antitrypsin was larger than the region of similarity. We propose that residues ECHQEEDFV represent the monoclonal antibody A10 epitope. They form an almost continuous sequence of residues 30–37 and 39 in ETSHR. The monoclonal antibody A10 binding site on antitrypsin is shorter. It comprises amino acids 205–208 and 210, from the region of similarity with, probably, additional two residues, H-287 and E 363.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.2005.01699.x
