High Affinity Binding of the Entamoeba histolytica Lectin to Polyvalent N-Acetylgalactosaminides

Adler, Pablo; Wood, Sheila; Lee, Yuan C.; Lee, Reiko T.; Petri, William A.; Schnaar, Ronald L.

doi:10.1074/jbc.270.10.5164

Cited by 86 publications

(66 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Recognition of host-specific mucin polysaccharides would allow the amoebae to use these sugars for simple attachment, while avoiding attempts at consuming the intestinal wall. Consistent with this hypothesis, the human-dwelling Entamoeba histolytica has been shown to strongly bind to the abundant mucin sugar N-acetylgalactosamine (Adler et al, 1995;Leroy et al, 1995). This sugar may be a receptor attachment site of E. histolytica, allowing it to reside in its adapted niche and avoid rapid expulsion from the colon.…”

Section: Discriminating Among Environmental Carbohydratesmentioning

confidence: 54%

Differential Salmonella survival against communities of intestinal amoebae

Wildschutte

Lawrence

2007

Microbiology

View full text Add to dashboard Cite

Predation from intestinal amoebae may provide selective pressure for the maintenance of high genetic diversity at the Salmonella enterica rfb locus, whereby serovars better escape predators in particular environments depending on the O-antigens they express. Here, the hypothesis that amoebae from a particular intestinal environment collectively prefer one serovar over another is tested. Collections of Acanthamoeba, Tetramitus, Naegleria and Hartmannella were isolated from the intestinal tracts of several vertebrate hosts, including bullfrog tadpoles, goldfish, turtles and bearded dragons, and their feeding preferences were determined. Congeneric amoebae from the same environment had significantly similar feeding preferences. Strikingly, even unrelated amoebae -such as Naegleria and Tetramitus from goldfish -also had significantly similar feeding preferences. Yet amoebae isolated from different environments showed no similarity in prey choice. Thus, feeding preferences of amoebae appear to reflect their environment, not their taxonomic relationships. A mechanism mediating this phenotypic convergence is discussed.

show abstract

Section: Discriminating Among Environmental Carbohydratesmentioning

confidence: 54%

Differential Salmonella survival against communities of intestinal amoebae

Wildschutte

Lawrence

2007

Microbiology

View full text Add to dashboard Cite

show abstract

“…The multiple subunits may endow multivalent binding properties to the MBP. This is of significant interest because it is well established that high affinity multivalent binding capable of clustering the receptors is often required for the biological function of most lectins (35,36).…”

Section: Discussionmentioning

confidence: 99%

Cloning and Characterization of a Novel Mannose-binding Protein of Acanthamoeba

Gárate

Cao

Bateman

et al. 2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

Acanthamoebae produce a painful, blinding infection of the cornea. The mannose-binding protein (MBP) of Acanthamoeba is thought to play a key role in the pathogenesis of the infection by mediating the adhesion of parasites to the host cells. We describe here the isolation and molecular cloning of Acanthamoeba MBP. The MBP was isolated by chromatography on the mannose affinity gel. Gel filtration experiments revealed that the Acanthamoeba lectin is a ϳ400-kDa protein that is constituted of multiple 130-kDa subunits. Cloning and sequencing experiments indicated that the Acanthamoeba MBP gene is composed of 6 exons and 5 introns that span 3.6 kb of the amoeba genome and that MBP cDNA codes for a precursor protein of 833 amino acids. That the cloned cDNA encodes authentic MBP was demonstrated by showing that: (i) recombinant MBP possesses mannose binding activity, and (ii) polyclonal antibodies prepared against Acanthamoeba MBP bound to the recombinant protein. Sequence analysis revealed that the MBP contains a large N-terminal extracellular domain, a transmembrane domain, and a short C-terminal cytoplasmic domain. Despite extensive BLAST searches using the MBP sequence, no significant matches were retrieved. The most striking feature of the Acanthamoeba MBP sequence is the presence of a cysteine-rich region containing 14 CXCXC motifs within the extracellular domain. In summary, we have isolated, cloned, and characterized a novel MBP from Acanthamoeba. Because the presence of antibodies to MBP in tears provides protection against infection, the availability of the MBP cDNA sequence and rMBP should help develop: (i) a tear-based test to identify individuals who are at risk of developing the keratitis and (ii) strategies to immunize high-risk individuals.Acanthamoebae are causative agents of two distinct disease entities. In immunocompromised individuals, this protozoan parasite produces chronic granulomatous amoebic encephalitis and disseminating infections including dermatitis and pneumonitis (1, 2). Granulomatous amoebic encephalitis is nearly always fatal because of the lack of an effective treatment. In immunocompetent individuals, Acanthamoebae provoke a debilitating vision-threatening corneal infection known as Acanthamoeba keratitis (AK) 1 (3-5). AK is characterized by intense pain and a slowly worsening clinical course. Contact lens wear is a major risk factor (3, 6, 7). In the developed world, ϳ85% of the cases are diagnosed in contact lens wearers (7). However, in the developing countries, where contact lens use is infrequent, the disease is more commonly found in non-contact lens wearers (8). The mechanism by which Acanthamoebae produce granulomatous amoebic encephalitis and AK has not been fully elucidated. It is generally accepted that the two major predisposing factors in the pathogenesis of AK are minor corneal trauma caused by contact lens wear or other noxious agents and exposure to contaminated solutions including lens care products and tap water (9, 10). The adhesion of parasites to the host cells ...

show abstract

“…Nevertheless, since the SPR response is proportional to the accumulation of mass on the sensor surface, a serious constraint imposed by this technique concerns the dimensions of the molecules to be employed as analytes. [7] In recent years, several groups have focused on SPR as an emerging technique to detect protein-carbohydrate interactions, [8][9][10][11][12][13][14][15][16][17][18][19][20] key steps in many biological events. [21,22] SPR studies of these biological events are hampered by the low availability of high-molecular-mass oligosaccharides and by the weakness of protein-carbohydrate interactions.…”

Section: Introductionmentioning

confidence: 99%

SPR Studies of Carbohydrate–Protein Interactions: Signal Enhancement of Low‐Molecular‐Mass Analytes by Organoplatinum(II)‐Labeling

et al. 2005

View full text Add to dashboard Cite

The relatively insensitive surface plasmon resonance (SPR) signal detection of low‐molecular‐mass analytes that bind with weak affinity to a protein—for example, carbohydrate–lectin binding—is hampering the use of biosensors in interaction studies. In this investigation, low‐molecular‐mass carbohydrates have been labeled with an organoplatinum(II) complex of the type [PtCl(NCNR)]. The attachment of this complex increased the SPR response tremendously and allowed the detection of binding events between monosaccharides and lectins at very low analyte concentrations. The platinum atom inside the organoplatinum(II) complex was shown to be essential for the SPR‐signal enhancement. The organoplatinum(II) complex did not influence the specificity of the biological interaction, but both the signal enhancement and the different binding character of labeled compounds when compared with unlabeled ones makes the method unsuitable for the direct calculation of biologically relevant kinetic parameters. However, the labeling procedure is expected to be of high relevance for qualitative binding studies and relative affinity ranking of small molecules (not restricted only to carbohydrates) to receptors, a process of immense interest in pharmaceutical research.

show abstract

High Affinity Binding of the Entamoeba histolytica Lectin to Polyvalent N-Acetylgalactosaminides

Cited by 86 publications

References 27 publications

Differential Salmonella survival against communities of intestinal amoebae

Differential Salmonella survival against communities of intestinal amoebae

Cloning and Characterization of a Novel Mannose-binding Protein of Acanthamoeba

SPR Studies of Carbohydrate–Protein Interactions: Signal Enhancement of Low‐Molecular‐Mass Analytes by Organoplatinum(II)‐Labeling

Contact Info

Product

Resources

About