Characterization of a post‐translational modification of Campylobacter flagellin: identification of a sero‐specific glycosyl moiety

Abstract

The flagellins of Campylobacter spp. differ antigenically. In variants of C. coli strain VC167, two antigenic flagellin types determined by sero-specific antibodies have been described (termed T1 and T2). Post-translational modification has been suggested to be responsible for T1 and T2 epitopes, and, using mild periodate treatment and biotin hydrazide labelling, flagellin from both VC167-T1 and T2 were shown to be glycosylated. Glycosylation was also shown to be present on other Campylobacter flagellins. The ability to label all Campylobacter flagellins examined with the lectin LFA demonstrated the presence of a terminal sialic acid moiety. Furthermore, mild periodate treatment of the flagellins of VC167 eliminated reactivity with T1 and T2 specific antibodies LAH1 and LAH2, respectively, and LFA could also compete with LAH1 and LAH2 antibodies for binding to their respective flagellins. These data implicate terminal sialic acid as part of the LAH strain-specific epitopes. However, using mutants in genes affecting LAH serorecognition of flagellin it was demonstrated that sialic acid alone is not the LAH epitope. Rather, the epitope(s) is complex, probably involving multiple glycosyl and/or amino acid residues.

Flagellin from an Incompatible Strain of Pseudomonas avenae Induces a Resistance Response in Cultured Rice Cells

“…Mild periodate treatment of the two flagellins eliminated reactivity with T1-and T2-specific antibodies. However, mutation analysis demonstrated that sugar alone is not the specific epitope, suggesting that the epitope probably involves multiple glycosyl and/or amino acid residues (55). These experimental data indicate that the sugar moiety is important for flagellin recognition by antibody in the mammal defense system.…”

“…The glycosylation of flagellin protein was first confirmed in Campylobacter coli by mild periodate treatment and biotin hydrazide labeling (55,56). It has been also reported that the glycosylation of flagellin is important in forming the specific epitope of H antigen.…”

Structure of the N-Linked Glycan Present on Multiple Glycoproteins in the Gram-negative Bacterium, Campylobacter jejuni

“…The ability to vary protein glycosylation has been described for M. tuberculosis Apa glycoproteins, which show differences in delayed-type hypersensitivity reactions and T-lymphocyte stimulation related to the extent of protein glycosylation (43,44). Other biological roles that carbohydrate modifications on bacterial glycoproteins have been shown to affect include adhesion (45), protection against proteolytic cleavage (46), solubility (47), antigenic variation (48), and protective immunity (49). In C. jejuni, alteration of the N-linked glycosylation pathway by mutation in the pgl locus has already been shown to influence adherence, invasion, colonization, and immunogenicity (3,4).…”

Genome-wide Expression Analyses of Campylobacter jejuni NCTC11168 Reveals Coordinate Regulation of Motility and Virulence by flhA

“…A number of these genes are involved in pseudaminic acid biosynthesis (including the 54 -regulated Cj1293 mentioned above). These include ptmA and ptmB (posttranslational modification proteins), homologues of CMP-Nacetylneuraminic acid synthetase and alcohol dehydrogenases, respectively (9,59). Mutation of these genes in C. jejuni 81-176 caused loss of flagellar reactivity with carbohydrate-specific sera and changes in the pI of the purified protein.…”