Specific binding of lactoferrin to Aeromonas hydrophila.
The interaction of lactoferrin (Lf) with Aeromonas hydrophila (n = 28) was tested in a 125I-labeled protein-binding assay. The mean per cent 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 microgram for 50% inhibition) than the homologous (10 micrograms 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.
Kishore
A R
AR
Department of Medical Microbiology, Malmö General Hospital, University of Lund, Sweden.
Erdei
J
J
Naidu
S S
SS
Falsen
E
E
Forsgren
A
A
Naidu
A S
AS
D016980:Aeromonas hydrophila / Q000378:metabolism*; D001665:Binding Sites; D015153:Blotting, Western; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007457:Iodine Radioisotopes; D007700:Kinetics; D007781:Lactoferrin / Q000378:metabolism*
D002352:Carrier Proteins; D007457:Iodine Radioisotopes; D007781:Lactoferrin