1. Identification and preliminary characterization of a 75-kDa hemin- and hemoglobin-binding outer membrane protein of Actinobacillus pleuropneumoniae serotype 1
- Author
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Marie, Archambault, Josée, Labrie, Clément R, Rioux, France, Dumas, Pierre, Thibault, Christopher, Elkins, and Mario, Jacques
- Subjects
Hemeproteins ,Swine ,Iron ,Actinobacillus pleuropneumoniae ,Article ,Molecular Weight ,Heme-Binding Proteins ,Hemoglobins ,Bacterial Proteins ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Animals ,Hemin ,Serotyping ,Carrier Proteins ,Bacterial Outer Membrane Proteins - Abstract
The reference strains representing serotypes 1 to 12 of Actinobacillus pleuropneumoniae biotype 1 were examined for their ability to utilize porcine hemoglobin (Hb) or porcine hemin (Hm) as iron sources for growth. In a growth promotion assay, all of the reference strains were able to use porcine Hb, and all strains except 2 were able to use porcine Hm. Using a preliminary characterization procedure with Hm- or Hb-agarose, Hm- and Hb-binding outer membrane proteins (OMPs) of approximately 75 kDa were isolated from A. pleuropneumoniae serotype 1 strain 4074 grown under iron-restricted conditions. Matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) analysis revealed a number of common tryptic peptides between the Hb-agarose- and Hm-agarose-purified 75 kDa OMPs, strongly suggesting that these peptides originate from the same protein. A database search of these peptide sequences revealed identities with proteins from various Gram-negative bacteria, including iron-regulated OMPs, transporter proteins, as well as TonB-dependent receptors. Taken together, our data suggest that A. pleuropneumoniae synthesizes potential Hm- and Hb-binding proteins that could be implicated in the iron uptake from porcine Hb and Hm.
- Published
- 2003