Identification of a Human Lactoferrin-Binding Protein in
            <i>Gardnerella vaginalis</i>

Jarosik, Gregory P.; Land, Carol Beth

doi:10.1128/iai.68.6.3443-3447.2000

Cited by 16 publications

(16 citation statements)

References 50 publications

(56 reference statements)

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“…In bacteria, iron-acquisition systems have been widely studied (Alderete et al, 1988;Gray-Owen & Schryvers, 1996;Jarosik & Land, 2000). However, the mechanisms of iron acquisition in protozoa are less well understood (Loo & Lalonde, 1984;Murray et al, 1991;Rodríguez & Jungery, 1986;Tachezy et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Human hololactoferrin: endocytosis and use as an iron source by the parasite Entamoeba histolytica

et al. 2005

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Entamoeba histolytica is an enteric protozoan that exclusively infects human beings. This parasite requires iron for its metabolic functions. Lactoferrin is a mammalian glycoprotein that chelates extracellular iron on mucosal surfaces, including the surface of the large intestine, where E. histolytica initiates infection. This work examined the interaction in vitro of E. histolytica trophozoites with human hololactoferrin (iron-saturated lactoferrin). A minimum concentration of 50 mM Fe from hololactoferrin supported growth of the amoeba. Amoebic binding sites for hololactoferrin were different from those for human apolactoferrin, holotransferrin and haemoglobin. One amoebic hololactoferrrin-binding polypeptide of 90 kDa was found, which was not observed after treatment of trophozoites with trypsin. Hololactoferrin-binding-protein levels increased in amoebas starved of iron, or grown in hololactoferrin. Internalization of hololactoferrin was inhibited by filipin. Endocytosed hololactoferrin colocalized with an anti-chick embryo caveolin mAb in amoebic vesicles, and lactoferrin was further detected in acidic vesicles; amoebic caveolin of 22 kDa was detected by Western blotting using this antibody. Cysteine proteases from amoebic extracts were able to cleave hololactoferrin. Together, these data indicate that E. histolytica trophozoites bind to hololactoferrin through specific membrane lactoferrin-binding proteins. This ferric protein might be internalized via caveolae-like microdomains, then used as an iron source, and degraded.

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Section: Introductionmentioning

confidence: 99%

Human hololactoferrin: endocytosis and use as an iron source by the parasite Entamoeba histolytica

et al. 2005

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“…10 Wl of the cell suspensions was then vacuum-blotted onto Immobilon-NC nitrocellulose ¢lters (Millipore, Bedford, MA, USA). After drying for 2 h at 37³C, the ¢lters were subjected to a dot blot assay as previously described [11]. Brie£y, after a 1-h incubation with a blocking solution consisting of 3% (w/v) skim milk dissolved in Tris-bu¡ered saline (TBS), pH 7.4, the ¢lters were incubated with DIGlabeled catalase (¢nal concentration 10 Wg ml 31 ) for 1 h at room temperature.…”

Section: Solid-phase Dot Blot Binding Assaymentioning

confidence: 99%

Binding of catalase by Gardnerella vaginalis

Jarosik

2000

FEMS Microbiology Letters

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Previous work has demonstrated that Gardnerella vaginalis can utilize catalase as a sole source of iron. In this study, the interaction between G. vaginalis cells and catalase was investigated. G. vaginalis cells were shown to bind digoxigenin (DIG)-labeled catalase using a solid phase dot blot assay. An increase in catalase binding was observed from cells grown under iron-restrictive conditions. Western blot analysis of G. vaginalis proteins resulted in the detection of a putative catalase-binding protein with an estimated molecular mass of 128 kDa. The 128-kDa catalase-binding protein was not detected from intact G. vaginalis cells treated with trypsin prior to Western blot analysis suggesting this protein may be surface-exposed. ß

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“…It has been previously demonstrated that G. vaginalis could also utilize hemoglobin, catalase, and lactoferrin as sole sources of iron and could directly bind these iron-containing compounds , JAROSIK and LAND 2000, LAND et al 1999). To Fig.…”

Section: Resultsmentioning

confidence: 99%

Binding of heme byGardnerella vaginalis

Jarosik

Land

2001

J. Basic Microbiol.

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It has been previously demonstrated that Gardnerella vaginalis could acquire iron from a number of different iron‐containing compounds, including heme. In this study, the direct binding of heme by G. vaginalis strains was demonstrated utilizing a liquid broth heme‐binding assay. Competition studies demonstrated that pretreatment of G. vaginalis cells with other iron sources such as hemoglobin, catalase, and lactoferrin did not affect heme binding. Also, heme binding was not inhibited by preincubation of G. vaginalis cells with protoporphyrin IX. Two potential heme‐binding proteins with estimated molecular weights of 30 and 70 kDa were isolated using heme‐agarose batch affinity chromatography.

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Identification of a Human Lactoferrin-Binding Protein in Gardnerella vaginalis

Cited by 16 publications

References 50 publications

Human hololactoferrin: endocytosis and use as an iron source by the parasite Entamoeba histolytica

Human hololactoferrin: endocytosis and use as an iron source by the parasite Entamoeba histolytica

Binding of catalase by Gardnerella vaginalis

Binding of heme byGardnerella vaginalis

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