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Specific binding of lactoferrin to Aeromonas hydrophila

1991; Oxford University Press; Volume: 83; Issue: 1 Linguagem: Inglês

10.1111/j.1574-6968.1991.tb04399.x

1574-6968

A R Kishore, J. Erdei, S. S. Naidu, Enevold Falsen, Arne Forsgren, A. Satyanarayan Naidu,

Neonatal and Maternal Infections

The interaction of lactoferrin (Lf) with Aeromonas hydrophila (n= 28) was tested in a 125I-labeled protein-binding assay. The mean percent binding values for human Lf (HLf) and bovine Lf (BLf) were 13.4±2.0 (SEM), and 17.5±2.7 (SEM), respectively. The Lf binding was characterized in type strain A. hydrophila subsp. hydrophila CCUG 14551. The HLf and BLf binding reached a complete saturation within 2 h. Unlabeled HLf and BLf displaced 125I-HLf binding in a dose-dependent manner, and more effectively by the heterologous (1 μg for 50% inhibition) than the homologous (10 μg for 50% inhibition) ligand. Apo- and holo-forms of HLf and BLf both inhibited more than 80%, while mucin caused approx. 50% inhibition of the HLf binding. Various other proteins (including transferrin) or carbohydrates did not block the binding. Two HLf-binding proteins with an estimated molecular masses of 40 kDa and 30 kDa were identified in a boiled-cell-envelope preparation, while the unboiled cell envelope demonstrated a short-ladder pattern at the top of the separating gel and a second band at approx. 60 kDa position. These data establish a specific interaction of Lf and the Lf-binding proteins seem to be porins in A. hydrophila.