40. SELECTIVE BINDING TO MANNAN OF GLIADIN PEPTIDES WHICH AGGLUTINATE UNDIFFERENTIATED K 562 S CELLS AND INHIBIT IN VITRO DEVELOPMENT OF FETAL RAT INTESTINE

Abstract

Mannan and N,N′-diacetyl-chitobiose and N,N′,N″-triacetyl-chitotriose prevent the agglutinating activity on K 562(5) cells and the damaging in vitro effect on fetal rat intestine and atrophic coeliac mucosa of mixtures of gliadin peptides and pure A-gliadin peptides (S.Auricchio et al., J. Ped. Gastroenterol. and Nutr. 4,923, 1985). We separated by cromatography on mannan-Sepharose 4-B of peptic-tryptic(PT) digest of gliadins: 1) A small fraction (C) which was very active in agglutinating cells and inhibiting the in vitro development of fetal rat intestine (20γ/ml medium). Both effects were prevented by the sugars. 2) A much larger fraction (B) which is devoid of both activities. These results show that only a few peptides of a gliadin digest, which are specifically bound by mannan, are active in the two in vitro systems.