title: Heterogeneous post-translational modification of Actinobacillus actinomycetemcomitans fimbrillin.
abstract: Fresh isolates of Actinobacillus actinomycetemcomitans produce bundle-forming fimbriae. The exact molecular mass of A. actinomycetemcomitans fimbrillin, a structural subunit of fimbriae, was determined by liquid chromatography-electrospray ionization mass spectrometry. Three major molecular species with 6,226.0, 6,366.0, and 6,513.0 Da were detected in a purified fimbrial fraction from the strain 310-a. These molecular masses were significantly higher than the molecular weight (5,118 Da) calculated from nucleotide sequence data of the fimbrillin gene, flp, suggesting that the fimbrial peptides were post-translationally modified. Modification of the fimbrial peptides was also suggested by an N-terminal amino acid sequence analysis of fimbrillin peptic fragments, with the modified amino acids being due to seven serine or asparagine residues located in the C-terminal region. A periodate oxidation/biotin-hydrazide labeling assay of fimbrillin suggested that it might be glycosylated.
authors.affiliation: Department of Microbiology, Okayama University Dental School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: H
authors.initials: H
authors.lastname: Ohta
authors.forename: I
authors.initials: I
authors.lastname: Tanimoto
authors.forename: R
authors.initials: R
authors.lastname: Shingaki
authors.forename: K
authors.initials: K
authors.lastname: Fukui
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000737:chemistry*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D036781:Fimbriae Proteins; D006031:Glycosylation; D008969:Molecular Sequence Data; D008970:Molecular Weight; D020033:Protein Isoforms / Q000302:isolation & purification / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D001426:Bacterial Proteins; D020033:Protein Isoforms; C063055:fimbrillin; D036781:Fimbriae Proteins