Primary structure of neutral oligosaccharides derived from respiratory‐mucus glycoproteins of a patient suffering from bronchiectasis, determined by combination of 500‐MHz 1H‐NMR spectroscopy and quantitative sugar analysis

Abstract

A pool of neutral carbohydrate chains was prepared from respiratory mucins of a patient suffering from bronchiectasis. Fractionation by HPLC led to 35 smaller‐size oligosaccharide‐alditols; the structure of 16 oligosaccharide‐alditols with core type 1 or type 2 has been established (Klein, A., Lamblin, G., Lhermitte, M., Roussel, P., Breg, J., Van Halbeek, H. & Vliegenthart, J. F. G., preceding paper in this journal). In this second part, we identified 19 oligosaccharide‐alditols possessing core types 3 and 4. Nine of the structures (1, 5, 9, 6, 10b, 13, 19, 15b and 18.1) have been described previously to be present in cystic fibrosis mucins [Lamblin, G., Boersma, A., Lhermitte, M., Roussel, P., Mutsaers, J. G. H. M., Van Halbeek, H. & Vliegenthart, J. F. G. (1984) Eur. J. Biochem. 143, 227–234]. The remaining ten are new structures isolated from bronchial mucins; they are all extensions of the above‐mentioned nine oligosaccharides. These compounds are octasaccharide‐alditols containing the Y determinant together with the H determinant of either backbone‐type 1 or 2, and partial structures thereof: and 21b, which is 23c without Fucα(1→3), 18.2, which is 23c without any Fuc in the 6‐branch, and 22b, which is 23c without Fuc in the 3‐branch.