Metabolic incorporation of unnatural sialic acids into Haemophilus ducreyi lipooligosaccharides.
Proc Natl Acad Sci U S A
; 100(6): 3089-94, 2003 Mar 18.
Article
em En
| MEDLINE
| ID: mdl-12615992
ABSTRACT
The lipooligosaccharides (LOS) of Haemophilus ducreyi are highly sialylated, a modification that has been implicated in resistance to host defense and in virulence. In previous work, we demonstrated that H. ducreyi scavenges sialic acid from the extracellular milieu and incorporates those residues into LOS. Here we report that H. ducreyi can use unnatural sialic acids bearing elongated N-acyl groups from three to seven carbon atoms in length, resulting in outer membrane presentation of unnatural sialyl-LOS. The unnatural variant comprises approximately 90% of cell surface sialosides when exogenous substrates are added to the media at micromolar concentrations, despite the availability of natural sialic acid in the growth media. Although they represent the majority of cell surface sialosides, analogs with longer N-acyl groups diminish the overall level of LOS sialylation, culminating in complete inhibition of LOS sialylation by N-octanoyl sialic acid. Thus, sialylation of H. ducreyi LOS can be modulated with respect to the structure of the terminal sialic acid residue and the extent to which the LOS acceptor is modified by supplying the bacteria with various sialic acid analogs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ácidos Siálicos
/
Haemophilus ducreyi
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Lipopolissacarídeos
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos