Purification and characterization of ferritin from Campylobacter jejuni.
We purified an iron-containing protein from Campylobacter jejuni using ultracentrifugation and ion-exchange chromatography. Electron microscopy of this protein revealed circular particles with a diameter of 11.5 nm and a central core with a diameter of 5.5 nm. The protein was composed of a single peptide of 21 kDa and did not serologically cross-react with horse spleen ferritin. The UV-visible spectrum of the protein showed no absorption peaks in the visible region, indicating that little or no heme is bound. The ratio of Fe:phosphate of C. jejuni ferritin was 1.5:1. From these morphological and chemical examinations, we concluded that the C. jejuni purified protein is a ferritin of the same class as that of Helicobacter pylori and Bacteroides fragilis and differs from the heme-containing bacterioferritin of Escherichia coli. The 30 N-terminal amino acids were sequenced and were found to resemble the sequences of other ferritins strongly (H. pylori ferritin, 73% identity; B. fragilis ferritin, 50% identity; E. coli gene-165 product, 50% identity), and to a lesser degree, bacterioferritins (E. coli bacterioferritin, 26% identity; Azotobacter vinelandii, 26% identity; horse spleen ferritin 30% identity). Proteins that cross-reacted with antiserum against the ferritin of C. jejuni were found in other Campylobacter species and in H. pylori, but not in Vibrio, E. coli, or Pseudomonas aeruginosa.
Wai
S N
SN
Department of Bacteriology, Faculty of Medicine, Kyushu University, Eukuoka, Japan.
Takata
T
T
Takade
A
A
Hamasaki
N
N
Amako
K
K
D000595:Amino Acid Sequence; D016123:Campylobacter jejuni / Q000737:chemistry*; D002499:Centrifugation, Density Gradient; D002852:Chromatography, Ion Exchange; D003429:Cross Reactions; D005293:Ferritins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D006090:Gram-Negative Bacteria / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016415:Sequence Alignment; D017421:Sequence Analysis
D005293:Ferritins