EFFECTS OF STRUCTURE MODIFICATIONS ON IGE BINDING-PROPERTIES OF SERUMALBUMINS

Background: Bovine serum albumin (BSA) is one of the most widely studi ed proteins; its structure is well-known and its antigenic characteris tics have been described in studies performed in in vitro and animal m odels. The aim of our work was to evaluate the role of BSA conformatio n in its antigenicity (recognition by circulating IgEs from allergic c hildren). Methods: This study was per formed using electrophoresis ass ociated with the immunoblotting technique, where sera from children se nsitized to BSA (as shown by double-blind placebo-controlled food chal lenge) were used. Results and Discussion: Heat treatment and chemical denaturation (SDS treatment) are not able to decrease the BSA capabili ty to bind circulating IgEs. Only by reducing treatment with 2-mercapt oethanol is it possible to modify but not to eliminate the antigenicit y of this protein. The reactivity to other serum albumins from differe nt animal species was also investigated and in this study we show a di rect correlation between the number of IgE-mediated responses observed in immunoblotting and the percentage of sequence identity (phylogenet ic similarity) of serum albumins. Conclusion: Data obtained in this re search indicate that serum albumin antigenicity is only partially corr elated to its native three-dimensional structure.