Iron binding proteins lactoferrin

So called because they are found in milk, where the iron-binding protein lactoferrin sequesters iron so tightly... 

Crouch, S.P., Slater, K.J., and Fletcher, J. 1992. Regulation of cytokine release from mononuclear cells by the iron-binding protein lactoferrin. Blood 80, 235 - 240. 

Gutteridge, J.M.C., Patterson, S.K., Segal, A.W., Halliwell, B. 1981. Inhibition of lipid peroxidation by the iron-binding protein lactoferrin. Biochem. J. 199, 259-261. 

Human colostrum and milk contain other substances important to the infant, for example the iron-binding protein lactoferrin and the enzyme lysozyme, both of which, like IgA, prevent infection within the digestive tract. It is going to be difficult for manufacturers of infant foods to include these substances in their products, and it seems important that all infants should have the benefits of colostrum and breast milk, even if only for a short time. 

Lactoferrin j Iron-binding protein May inhibit growth of certain bacteria by binding iron and may be involved in regulation of proliferation of myeloid cells... 

Transferrin iron uptake via receptor-mediated endocytosis has clearly appeared fairly late in evolution, when we consider that the bilobal iron-binding protein is found only as far back as insects . As we have seen in the preceding chapters, iron-uptake mechanisms involving the synthesis of more or less specific siderophores have evolved together with strategies implying the solubilization of insoluble ferric iron by the combined effects of pH and reduction, and even the development of receptor proteins capable of taking up transferrin-, lactoferrin- or haem-bound iron from specific hosts. 

The transferrins are proteins that bind and transport iron as peIII 16-U.8 They indude lactoferrin from milk, ovotransferrin from egg white, and serum transferrin from a range of organisms. Uteroferrin, considered in Section 62.1.5.5.2 on the purple acid phosphatases, is an iron-binding protein with phosphatase activity, that has been proposed to transport iron from maternal to foetal circulation.824 826 There are distinct differences between the iron-binding sites in uteroferrin and transferrin, and so uteroferrin will not be discussed in this section. 

Human lactoferrin (HL) is a component of innate immunity. Human lactoferrin is an iron-binding protein found in milk, granulocytes and exocrine secretions. It is released during inflammation, has bactericidal effects and reduces cytokine production by binding to the lipid A portion of endotoxin (Appelmelk et al., 1994). 

Masson, P.L. and Heremans, J.F. 1966. Studies on lactoferrin, the iron-binding protein of secretions. Prot. Biol. Fluids 14, 115-142. 

We subsequently used extrinsically labeled diets for further fractionation by gel filtration and immunoaffinity chromatography. Mn in human milk was found to be predominantly (about 70%) bound to lactoferrin, the major iron-binding protein in human milk. Minor amounts were bound to casein in human milk and the milk fat globule membrane. It is therefore possible that changes in lactoferrin concentration in human milk may explain the developmental pattern... 

Figure 3.3. Flexibility aud Fuuctiou. Upon binding iron, the protein lactoferrin undergoes conformational changes that...

Figure 2.3 Flexibility and function. On binding iron, the protein lactoferrin undergoes a substantial change in conformation that allows other molecules to distinguish between the iron free and the iron-bound forms. [Drawn from ILFM.pdp and ILFG.pdb.]...

Lactoferrin (from hnman whey) [55599-62-7, Fe Salty 90,000. This iron-binding protein is purified by direct adsorption on cellulose phosphate by batch extraction, then eluted by a stepped salt and pH gradient. The Fe bound protein forms red crystals with Lmax at 465nm (pH 8.2). [Foley Bates Anal Biochem 162 296 79S7.]... 

To meet these metabolic requirements, nature has developed protein ligands which maintain iron in a soluble, bioavailable form while preventing it from catalyzing reactions that produce harmful oxidative products. These iron-binding proteins are transferrin, lactoferrin, and ferritin. 

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