High mannose-binding lectin with preference for the cluster of alpha1-2-mannose from the green alga Boodlea coacta is a potent entry inhibitor of HIV-1 and influenza viruses.
J Biol Chem
; 286(22): 19446-58, 2011 Jun 03.
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| MEDLINE
| ID: mdl-21460211
ABSTRACT
The complete amino acid sequence of a lectin from the green alga Boodlea coacta (BCA), which was determined by a combination of Edman degradation of its peptide fragments and cDNA cloning, revealed the following 1) B. coacta used a noncanonical genetic code (where TAA and TAG codons encode glutamine rather than a translation termination), and 2) BCA consisted of three internal tandem-repeated domains, each of which contains the sequence motif similar to the carbohydrate-binding site of Galanthus nivalis agglutinin-related lectins. Carbohydrate binding specificity of BCA was examined by a centrifugal ultrafiltration-HPLC assay using 42 pyridylaminated oligosaccharides. BCA bound to high mannose-type N-glycans but not to the complex-type, hybrid-type core structure of N-glycans or oligosaccharides from glycolipids. This lectin had exclusive specificity for α1-2-linked mannose at the nonreducing terminus. The binding activity was enhanced as the number of terminal α1-2-linked mannose substitutions increased. Mannobiose, mannotriose, and mannopentaose were incapable of binding to BCA. Thus, BCA preferentially recognized the nonreducing terminal α1-2-mannose cluster as a primary target. As predicted from carbohydrate-binding propensity, this lectin inhibited the HIV-1 entry into the host cells at a half-maximal effective concentration of 8.2 nm. A high association constant (3.71 × 10(8) M(-1)) of BCA with the HIV envelope glycoprotein gp120 was demonstrated by surface plasmon resonance analysis. Moreover, BCA showed the potent anti-influenza activity by directly binding to viral envelope hemagglutinin against various strains, including a clinical isolate of pandemic H1N1-2009 virus, revealing its potential as an antiviral reagent.
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Bases de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
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VIH-1
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Lectinas de Unión a Manosa
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Chlorophyta
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Subtipo H1N1 del Virus de la Influenza A
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Internalización del Virus
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Manosa
Límite:
Animals
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Humans
Idioma:
En
Revista:
J Biol Chem
Año:
2011
Tipo del documento:
Article
País de afiliación:
Japón