Human lactotransferrin: amino acid sequence and structural comparisons with other transferrins

Metz‐Boutigue, Marie‐Hélène; Jollès, Jacqueline; Mazurier, Joël; Schoentgen, FranGoise; Legrand, Dominique; Spik, Geneviève; Montreuil, Jean; Jollès, Pierre

doi:10.1111/j.1432-1033.1984.tb08607.x

Cited by 501 publications

(183 citation statements)

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“…Human lactoferrin (hLF) is an 80-kDa iron-binding glycoprotein of 703 amino acids (8). It constitutes about 15% of human milk protein and also can be found in low concentrations in blood plasma, tears, nasal fluids, saliva, pancreatic, gastrointestinal, and reproductive tissue secretions (9).…”

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confidence: 99%

A Cell-penetrating Peptide Derived from Human Lactoferrin with Conformation-dependent Uptake Efficiency

Duchardt

Ruttekolk

Verdurmen

et al. 2009

Journal of Biological Chemistry

112

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The molecular events that contribute to the cellular uptake of cell-penetrating peptides (CPP) are still a matter of intense research. Here, we report on the identification and characterization of a 22-amino acid CPP derived from the human milk protein, lactoferrin. The peptide exhibits a conformation-dependent uptake efficiency that is correlated with efficient binding to heparan sulfate and lipid-induced conformational changes. The peptide contains a disulfide bridge formed by terminal cysteine residues. At concentrations exceeding 10 M, this peptide undergoes the same rapid entry into the cytoplasm that was described previously for the arginine-rich CPPs nona-arginine and Tat. Cytoplasmic entry strictly depends on the presence of the disulfide bridge. To better understand this conformation dependence, NMR spectroscopy was performed for the free peptide, and CD measurements were performed for free and lipidbound peptide. In solution, the peptides showed only slight differences in secondary structure, with a predominantly disordered structure both in the presence and absence of the disulfide bridge. In contrast, in complex with large unilamellar vesicles, the conformation of the oxidized and reduced forms of the peptide clearly differed. Moreover, surface plasmon resonance experiments showed that the oxidized form binds to heparan sulfate with a considerably higher affinity than the reduced form. Consistently, membrane binding and cellular uptake of the peptide were reduced when heparan sulfate chains were removed.

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mentioning

confidence: 99%

A Cell-penetrating Peptide Derived from Human Lactoferrin with Conformation-dependent Uptake Efficiency

Duchardt

Ruttekolk

Verdurmen

et al. 2009

Journal of Biological Chemistry

112

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“…1), although Tf is homologous to Lf in structure and has similar iron-binding properties. 27) These results suggest that mechanisms distinct from a putative receptor-mediated iron-transport mechanism are involved in mediating the observed Lf-induced stimulation of NGF synthesis in L-M cells.…”

Section: Resultsmentioning

confidence: 65%

Stimulation by Bovine Lactoferrin of Nerve Growth Factor Synthesis/Secretion in Mouse L-M Cells

Shinoda

Fukuwatari

Shimamura

et al. 1993

Bioscience, Biotechnology, and Biochemistry

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“…The sequence numbering has been modified by the addition of one additional arginine residue to reflect the N-terminal amino acid sequence data for human milk lactoferrin determined by us (Table 1) and by others (28). The crystal structure sequence numbering in the N terminus is therefore modified accordingly (+1) relative to that of Metz-Boutigue et al (28) beginning at Ser-6. The corrected sequence, containing four arginines (residues 2-5), has been confirmed by the cDNA sequence for human lactoferrin (18).…”

Section: Resultsmentioning

confidence: 99%

Structurally intact (78-kDa) forms of maternal lactoferrin purified from urine of preterm infants fed human milk: identification of a trypsin-like proteolytic cleavage event in vivo that does not result in fragment dissociation.

Hutchens

Henry

Yip

1991

Proc. Natl. Acad. Sci. U.S.A.

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Two forms of lactoferrin, an intact lactoferrin and a "nicked" but apparently intact (i.e., 78-kDa) form, have been isolated from the urine of preterm infants fed human milk. These two forms of lactoferrin, demonstrated to be entirely of maternal origin, were copurified using affinity columns of immobilized single-stranded DNA-agarose. The relative concentrations of the intact lactoferrin and the "nicked" lactoferrin were determined after denaturation and separation by reverse-phase HPLC. N-terminal sequence analyses showed that the Intact 78-kDa form had lost two residues from its N terminus. The nicked 78-kDa form was composed of only two fragments; one fragment was identified as the N terminus of the N-lobe (residues 3-283). The other fragment started with Ser-284 and included the a-helical structures at the C terminus of the N-lobe, as well as the entire C-lobe. Although no disulfide bonds connect these two fragments, they were tightly associated in vivo and were not separated in vitro except under denaturing conditions. Limited in vitro digestion of human milk lactoferrin with trypsin produced a nicked, but stable (78-kDa), form of DNA-binding lactoferrin nearly indistinguishable from the isolated urinary lactoferrin, except for the absence of one additional arginine residue at the N terminus of the N-lobe. Residues involved in the stable molecular interaction between fragments were evaluated using data obtained from the high-resolution crystal structure of hololactoferrin. Two features, entirely within the N-lobe, account for the lack of fragment dissociation after cleavage at residue 283 in vivo: an extensive interface at the hinge region behind the ironbinding cleft and an "anchor" sequence traversing the remainder ofthe N-lobe at 90' relative to the fragment interface. These results document the remarkably limited degradation of absorbed lactoferrin in vivo and suggest that iron-binding activity, receptor-binding properties, and postulated immune cell regulatory functions remain intact.Lactoferrin is a 78-kDa metal-binding protein found in milk and various other mucosal secretions (1). It is also a component of neutrophil secretory granules and is generally thought to be important in host defense (1, 2). It has been associated with the promotion of cell growth (e.g., refs. 3 and 4), regulation of hematopoiesis, and immune-modulating properties (e.g., refs. 5-8) in vitro. Little, however, is known about the function and metabolism of lactoferrin in vivo.Lactoferrin is the major protein component of human colostral whey (9) and has been a focus of attention in numerous investigations of the nutrition and host defense of term and preterm infants (10-17). Since human lactoferrin has been cloned (18), overexpression and large-scale production are imminent. Thus, an increased need for the characterization of lactoferrin structure, function, and metabolism in vitro is anticipated. We have reported the identification and purification of intact (78- (20). In addition to identifying intact lactoferrin in ...

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Human lactotransferrin: amino acid sequence and structural comparisons with other transferrins

Cited by 501 publications

References 50 publications

A Cell-penetrating Peptide Derived from Human Lactoferrin with Conformation-dependent Uptake Efficiency

A Cell-penetrating Peptide Derived from Human Lactoferrin with Conformation-dependent Uptake Efficiency

Stimulation by Bovine Lactoferrin of Nerve Growth Factor Synthesis/Secretion in Mouse L-M Cells

Structurally intact (78-kDa) forms of maternal lactoferrin purified from urine of preterm infants fed human milk: identification of a trypsin-like proteolytic cleavage event in vivo that does not result in fragment dissociation.

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