Clostridium botulinum type A haemagglutinin-positive progenitor toxin (HA(+)-PTX) binds to oligosaccharides containing Gal beta 1-4GlcNAc through onesubcomponent of haemagglutinin (HA1)
K. Inoue et al., Clostridium botulinum type A haemagglutinin-positive progenitor toxin (HA(+)-PTX) binds to oligosaccharides containing Gal beta 1-4GlcNAc through onesubcomponent of haemagglutinin (HA1), MICROBIO-UK, 147, 2001, pp. 811-819
Haemagglutinin (HA) activity of Clostridium botulinum type A 19S and 16S to
xins (HA-positive progenitor toxin; HA(+)-PTX) was characterized. HA titres
against human erythrocytes of HA(+)-PTX were inhibited by the addition of
lactose, D-gatactose, N-acetyl-D-galactosamine and D-fucose to the reaction
mixtures. A direct glycolipid binding test demonstrated that type A HA(+)-
PTX strongly bound to paragloboside and some neutral glycolipids, but did n
ot bind to gangliosides. Type A HA(+)-PTX also bound to asialoglycoproteins
(asialofetuin, neuraminidase-treated transferrin). but not to sialoglycopr
oteins (fetuin, transferrin). Although glycopeptidase F treatment of asialo
fetuin abolished the binding of HA(+)-PTX, endo-alpha -N-acetylgalactosamin
idase treatment did not. Thus these results can be interpreted as indicatin
g that type A HA(+)-PTX detects and kinds to Gal beta1-4GlcNAc in paraglobo
side and the N-linked oligosaccharides of glycoproteins. Regardless of neur
aminidase treatment type A HA(+)-PTX bound to glycophorin A which is a majo
r sialoglycoprotein on the surface of erythrocytes. Both native glycophorin
A and neuraminidase-treated glycophorin A inhibited the binding of erythro
cytes to type A HA(+)-PTX. Since the N-linked oligosaccharide of glycophori
n A is di-branched and more than 50% of this sugar chain is monosialylated,
type A HA(+)-PTX probably bound to the unsialylated branch of the N-linked
oligosaccharide of glycophorin A and agglutinated erythrocytes. One subcom
ponent of HA, designated HA1, did not agglutinate native erythrocytes, alth
ough it did bind to erythrocytes, paragloboside and asialoglycoproteins in
a manner quite similar to that of HA(+)-PTX. These results indicate that ty
pe A HA(+)-PTX binds to oligosaccharides through HA1.