Y. Takaya et al., ILLEXIN-A, ILLEXIN-B, AND ILLEXIN-C FROM SQUID INK SHOULD HAVE A BRANCHED STRUCTURE, Biochemical and biophysical research communications, 226(2), 1996, pp. 335-338
Ilexin A, illexin B, and illexin C, isolated from ink of the squid Ill
ex argentinus, have been reported to have a structure consisting of li
near repeating units of (-6GalNAc alpha 1-3GlcA beta 1-3Fuc alpha 1-)(
n) [Biochem. Biophys. Res. Commun. 198, 560 (1994)]. This structure wa
s further investigated using NOESY and atmospheric pressure MS/MS meas
urement of PA-trisaccharide obtained by acid hydrolysis of illexin C.
The results indicated that the structure is, in fact, branched. Observ
ation of both [GalNAc-Fuc-PA](+) and [GlcA-Fuc-PA](-) obtained as prod
uct ions from the molecular ion of PA-trisaccharide on the MS/MS spect
ra suggested a branched repeating unit. NOEs between H-1 of GalNAc and
H-3 of Fuc, and between H-1 of GlcA and H-4 of Fuc, revealed the posi
tions of glycosidic linkages, and from the results of sodium periodate
oxidation of illexin C and PA-trisaccharide, the structure was determ
ined to be (-3GlcA beta 1-4(GalNAc alpha 1-3)Fuc alpha 1-}(n). (C) 199
6 Academic Press, Inc.