Detection and identification of a soy protein component that cross reacts with caseins from cow milk

ROZENFELD P.; DOCENA G; FOSSATI C.A.; AÑON, MARÍA CRISTINA

CLINICAL AND EXPERIMENTAL IMMUNOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2002 vol. 130 p. 49 - 58

0009-9104

Soy-based formulas are the most employed cow?s milk substitutes in the treatment of cow?s milk allergyin our country. Since adverse reactions have been reported in allergic patients as a consequence ofexposure to soy proteins, we have investigated the possible cross-reactivity between components fromsoybean and cow?s milk. A cow?s milk specific polyclonal antiserum and casein specific monoclonal anti-bodies were used in immunoblotting and competitive ELISA studies to identify a 30-kD componentfrom soybean that cross-reacts with cow?s milk caseins. Its IgE binding capacity was tested by EAST,employing sera from cow?s milk allergic patients, not previously exposed to soy proteins. The 30 kDprotein was isolated and partially sequenced. It is constituted by two polypeptides (A5and B3) linkedby a disulphide bond. The protein?s capacity to bind to the different antibodies relies on the B3poly-peptide. These results indicate that soy-based formula, which contains the A5-B3 glycinin molecule, could be involved in allergic reactions observed in cow?s milk allergic patients exposed tosoy-containing foods.