Human alpha 3-fucosyltransferases convert chitin oligosaccharides to products containing a GlcNAc beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-4R determinantat the nonreducing terminus

Human alpha3-fucosyltransferases (Fuc-Ts) are known to convert N-acetyllact osamine to Gal beta1-4(Fuc alpha1-3)GlcNAc (Lewis x antigen); some of them transfer fucose also to GalNAc beta1-4GlcNAc, generating GalNAc beta1-4(Fuc alpha1-3)GlcNAc determinants. Here, we report that recombinant forms of Fu c-TV and Fuc-TVI as well as Fuc-Ts of human milk converted chitin oligosacc harides of 2-4 GlcNAc units efficiently to products containing a GlcNAc bet a1-4(Fuc alpha1-3)GlcNAc beta1-4R determinant at the nonreducing terminus. The product structures were identified by mass spectrometry and nuclear mag netic resonance experiments; rotating frame nuclear Overhauser spectroscopy data suggested that the fucose and the distal N-acetylglucosamine are stac ked in the same way as the fucose and the distal galactose of the Lewis x d eterminant. The products closely resembled a nodulation factor of Mesorhizo bium loti but were distinct from nodulation signals generated by NodZ-enzym e.