The role of lactoferrin binding protein B in mediating protection against human lactoferricin

Ari Morgenthau, Margaret Livingstone, Paul Adamiak, Anthony B. Schryvers

Research output: Contribution to journalReview ArticleResearchpeer-review

28 Citations (Scopus)

Abstract

Bacteria that inhabit the mucosal surfaces of the respiratory and genitourinary tracts of mammals encounter an iron-deficient environment because of iron sequestration by the host iron-binding proteins transferrin and lactoferrin. Lactoferrin is also present in high concentrations at sites of inflammation where the cationic, antimicrobial peptide lactoferricin is produced by proteolysis of lactoferrin. Several Gram-negative pathogens express a lactoferrin receptor that enables the bacteria to use lactoferrin as an iron source. The receptor is composed of an integral membrane protein, lactoferrin binding protein A (LbpA), and a membrane-bound lipoprotein, lactoferrin binding protein B (LbpB). LbpA is essential for growth with lactoferrin as the sole iron source, whereas the role of LbpB in iron acquisition is not yet known. In this study, we demonstrate that LbpB from 2 different species is capable of providing protection against the killing activity of a human lactoferrin- derived peptide. We investigated the prevalence of lactoferrin receptors in bacteria and examined their sequence diversity. We propose that the protection against the cationic antimicrobial human lactoferrin-derived peptide is associated with clusters of negatively charged amino acids in the C-terminal lobe of LbpB that is a common feature of this protein.

Original languageEnglish
Pages (from-to)417-423
Number of pages7
JournalBiochemistry and Cell Biology
Volume90
Issue number3
DOIs
Publication statusPublished - Jun 2012
Externally publishedYes

Keywords

  • Binding protein
  • Cationic antimicrobial peptide
  • Iron transport
  • Lactoferricin
  • Lactoferrin

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