Immunochemical study of soybean proteins that cross react with cow’s milk proteins.

LAREU, FABRICIO,; DOCENA, GUILLERMO HORACIO; PETRUCCELLI, SILVANA*,

Foz Iguazu

Congreso; XXXX Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2004

SAIB

Soy based formulas are used as milk substitute for cows´ milk protein allergic (CMPA) infants because are cheaper and more palatable than other formulas. Approximately, 10% to 35% of CMPA infants do not tolerate soy proteins. Identification of crossreactive proteins will give valuable information to develop soy based hypoallergenic substitutes. We have identified glycinin A4A5B3 as one of the proteins that cross-reacts with cows’ milk proteins. The aim of this work was to analyzed the cross reactivity of a soybean varieties that naturally lacks A4A5B3 (Raiden). Soy proteins obtained from conventional and Raiden seeds and recombinant glycinin A2B1a, A4A5B3 and α subunit β-conglycinin were used in this study. Cross-reactive proteins were analyzed by ELISA and Western Blot using a rabbit polyclonal antiserum obtained using CMP as immunogen and three monoclonal antibodies (mAb) with high specificity for α- (1D5), β- (2A1) and κ-casein (3B5). Conventional soybean has only one protein of 23kDa that has reactivity with the anti-milk polyclonal serum and four proteins (23, 37, 53 and 57kDa) that show strong reactivity to the mAbs 2A1 and 3B5. In contrast, Raiden has only one protein (57kDa) that cross reacts with CMP; that was identified as αα’-β-conglycinin using soybean purified and recombinant αα’subunits. mAbs 2A1 and 3B5 shows reactivity against recombinant A4A5B3 while  mAb 1D5-I did not. This results confirm the cross reactivity of  A4A5B3 with CMP and open the possibility of use of Raiden as cow milk substitute. A4A5B3 as one of the proteins that cross-reacts with cows’ milk proteins. The aim of this work was to analyzed the cross reactivity of a soybean varieties that naturally lacks A4A5B3 (Raiden). Soy proteins obtained from conventional and Raiden seeds and recombinant glycinin A2B1a, A4A5B3 and α subunit β-conglycinin were used in this study. Cross-reactive proteins were analyzed by ELISA and Western Blot using a rabbit polyclonal antiserum obtained using CMP as immunogen and three monoclonal antibodies (mAb) with high specificity for α- (1D5), β- (2A1) and κ-casein (3B5). Conventional soybean has only one protein of 23kDa that has reactivity with the anti-milk polyclonal serum and four proteins (23, 37, 53 and 57kDa) that show strong reactivity to the mAbs 2A1 and 3B5. In contrast, Raiden has only one protein (57kDa) that cross reacts with CMP; that was identified as αα’-β-conglycinin using soybean purified and recombinant αα’subunits. mAbs 2A1 and 3B5 shows reactivity against recombinant A4A5B3 while  mAb 1D5-I did not. This results confirm the cross reactivity of  A4A5B3 with CMP and open the possibility of use of Raiden as cow milk substitute. 4A5B3 as one of the proteins that cross-reacts with cows’ milk proteins. The aim of this work was to analyzed the cross reactivity of a soybean varieties that naturally lacks A4A5B3 (Raiden). Soy proteins obtained from conventional and Raiden seeds and recombinant glycinin A2B1a, A4A5B3 and α subunit β-conglycinin were used in this study. Cross-reactive proteins were analyzed by ELISA and Western Blot using a rabbit polyclonal antiserum obtained using CMP as immunogen and three monoclonal antibodies (mAb) with high specificity for α- (1D5), β- (2A1) and κ-casein (3B5). Conventional soybean has only one protein of 23kDa that has reactivity with the anti-milk polyclonal serum and four proteins (23, 37, 53 and 57kDa) that show strong reactivity to the mAbs 2A1 and 3B5. In contrast, Raiden has only one protein (57kDa) that cross reacts with CMP; that was identified as αα’-β-conglycinin using soybean purified and recombinant αα’subunits. mAbs 2A1 and 3B5 shows reactivity against recombinant A4A5B3 while  mAb 1D5-I did not. This results confirm the cross reactivity of  A4A5B3 with CMP and open the possibility of use of Raiden as cow milk substitute.