Interaction of lactoferrin withEscherichia colicells and correlation with antibacterial activity

✍ Scribed by Paolo Visca; Claudia Dalmastri; Daniela Verzili; Giovanni Antonini; Emilia Chiancone; Piera Valenti

• Book ID: 104656778
• Publisher: Springer-Verlag
• Year: 1990
• Tongue: English
• Weight: 577 KB
• Volume: 179
• Category: Article
• ISSN: 0300-8584
• DOI: 10.1007/bf00189610

✦ Synopsis

It has been established that the antimicrobial activity of lactoferrin towards Escherichia coli is enhanced by a direct contact between the protein and the microbial cell and that, in the case of E. coli K-12 strains, an antibacterial activity of lactoferrin unrelated to iron withdrawal is present. Evidence is now reported that lactoferrin binds to surface structures expressed in E. coli K-12 strains grown in either an "excess" or "stress" of iron. Under the experimental conditions used, lactoferrin binding both in the apo and in the iron-saturated form yields a maximum of 1.6 X 10(5) bound molecules/E. coli K-12 cell; the amount of lactoferrin bound does not depend on the expression of the iron-regulated outer membrane proteins. In contrast, lactoferrin does not bind to E. coli clinical isolates. Apo-lactoferrin (at 500 micrograms/ml in a chemically defined medium) inhibits the growth of E. coli K-12 strains but not of clinical isolates. These findings suggest that the antibacterial activity of the protein could be associated to its binding to the cell surface.