ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Pseudomonas aeruginosa employs pili to mediate adherence to epithelial cell surfaces. The pilus adhesin of P. aeruginosa strains PAK and PAO has been shown to bind to the glycolipid asialo-GM1 (Lee et al., 1994 —accompanying article). PAK and PAO pili were examined for their abilities to bind to the synthetic βGalNAc(1–4)βGal (a minimal structural carbohydrate receptor sequence of asialo-GM1 and asialo-GM2 proposed by Krivan et al., 1988a) using solid-phase binding assays. Both pill specifically bound to βGalNAc(1–4)βGal. The binding of βGal-NAc(1–4)βGal-Biotin to the Immobilized PAK and PAO pili was inhibited by corresponding free pili. The receptor binding domain of the PAK pilus resides in the C-terminal disulphide-looped region (residues 128–144) of the pilin structural subunit (Irvin et al., 1989). Biotinylated synthetic peptides corresponding the C-terminal residues 128–144 of P. aeruginosa PAK and PAO pilin molecules were shown to bind to the βGalNAc(1–4)βGal-(bovine serum albumin (BSA)). The binding of biotinylated peptides to βGalNAc-(1–4)βGal-BSA was inhibited by PAK pili, Ac-KCTSDQDEOFIPKGCSK-OH (AcPAK(128–144)ox-OH) and Ac-ACKSTQDPMFTPKGCDN-OH (AcPAO(128–144)ox-OH) peptides. (In these peptides Ac denotes Nα -acetylation of the N-terminus, -OH means a peptide with a free a-carboxyl group at the C-terminus and the‘ox’denotes the oxidation of the sulphhydryl groups of Cys–129 and Cys–142.) Both acetylated peptides were also able to inhibit the binding of βGalNAc(1–4)βGal-biotin to the corresponding BSA-Peptide(128–144)ox-OH conjugates. The βGlcNAc(1–3)βGal(1–4)βGlc-biotin conjugate was unable to specifically bind to either Immobilized PAK and PAO pili or the respective C-termlnal peptides. The data above demonstrated that the P. aeruginosa pili recognize asialo-GM1 receptor analogue and that βGalNAc(1–4)βGal disaccharlde is sufficient for binding. Furthermore, the binding to βGalNAc(1–4)βGal was mediated by residues 128–144 of the pilin subunit.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.1994.tb00349.x
