A structural comparison of human serum transferrin and human lactoferrin
Open Access
- 11 January 2007
- journal article
- review article
- Published by Springer Science and Business Media LLC in BioMetals
- Vol. 20 (3-4), 249-262
- https://doi.org/10.1007/s10534-006-9062-7
Abstract
The transferrins are a family of proteins that bind free iron in the blood and bodily fluids. Serum transferrins function to deliver iron to cells via a receptor-mediated endocytotic process as well as to remove toxic free iron from the blood and to provide an anti-bacterial, low-iron environment. Lactoferrins (found in bodily secretions such as milk) are only known to have an anti-bacterial function, via their ability to tightly bind free iron even at low pH, and have no known transport function. Though these proteins keep the level of free iron low, pathogenic bacteria are able to thrive by obtaining iron from their host via expression of outer membrane proteins that can bind to and remove iron from host proteins, including both serum transferrin and lactoferrin. Furthermore, even though human serum transferrin and lactoferrin are quite similar in sequence and structure, and coordinate iron in the same manner, they differ in their affinities for iron as well as their receptor binding properties: the human transferrin receptor only binds serum transferrin, and two distinct bacterial transport systems are used to capture iron from serum transferrin and lactoferrin. Comparison of the recently solved crystal structure of iron-free human serum transferrin to that of human lactoferrin provides insight into these differences.Keywords
This publication has 70 references indexed in Scilit:
- The Crystal Structure of Iron-free Human Serum Transferrin Provides Insight into Inter-lobe Communication and Receptor BindingOnline Journal of Public Health Informatics, 2006
- Crystal Structure at High Resolution of Ferric-pyochelin and its Membrane Receptor FptA from Pseudomonas aeruginosaJournal of Molecular Biology, 2005
- The Crystal Structure of the Pyoverdine Outer Membrane Receptor FpvA from Pseudomonas aeruginosa at 3.6Å ResolutionJournal of Molecular Biology, 2005
- Mechanism for Multiple Ligand Recognition by the Human Transferrin ReceptorPLoS Biology, 2003
- “Dilysine Trigger” in Transferrins Probed by Mutagenesis of Lactoferrin: Crystal Structures of the R210G, R210E, and R210L Mutants of Human Lactoferrin,Biochemistry, 2002
- Camel Lactoferrin, a Transferrin-cum-Lactoferrin: Crystal Structure of Camel Apolactoferrin at 2.6Å Resolution and Structural Basis of its Dual RoleJournal of Molecular Biology, 2001
- A Dynamic Model of the Meningococcal Transferrin ReceptorJournal of Theoretical Biology, 1999
- SWISS‐MODEL and the Swiss‐Pdb Viewer: An environment for comparative protein modelingElectrophoresis, 1997
- CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choiceNucleic Acids Research, 1994
- Structure of human lactoferrin: Crystallographic structure analysis and refinement at 2·8 Å resolutionJournal of Molecular Biology, 1989