In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 100, No. 6 ( 2003-03-18), p. 3089-3094
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 ≈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.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.0437851100
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2003
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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