Purification and characterization of a lectin, BPL-3, from the marine green alga Bryopsis plumosa

Abstract

A novel lectin was isolated and characterized from Bryopsis plumosa (Hudson) Agardh and named BPL-3. This lectin showed specificity to N-acetyl-D-galactosamine as well as N-acetyl-D-glucosamine and agglutinated human erythrocytes of all blood types, showing slight preference to the type A. SDS-PAGE and MALDI-TOF MS data showed that BPL-3 was a monomeric protein with molecular weight of 11.5 kDa. BPL-3 was a non-glycoprotein with pI value of ∼7.0. It was stable in high temperatures up to 70°C and exhibited optimum activity in pH 5.5-10. The N-terminal and internal amino acid sequences of the lectin were determined by Edman degradation and enzymatic digestion, which showed no sequence homology to any other reported proteins. The full sequence of the cDNA encoding this lectin was obtained from PCR using cDNA library, and the degenerate primers were designed from the N-terminal amino acid sequence. The size of the cDNA was 622 bp containing single ORF encoding the lectin precursor. This lectin showed the same sugar specificity to previously reported lectin, Bryohealin, involved in protoplast regeneration of B. plumosa. However, the amino acid sequences of the two lectins were completely different. The homology analysis of the full cDNA sequence of BPL-3 showed that it might belong to H lectin group, which was originally isolated from Roman snails.

Molecular characterization of a lectin, BPL-4, from the marine green alga Bryopsis plumosa (Chlorophyta)

“…First, a degenerate forward primer [BPL4-NDF1, 5′-CA(A/G) plants. Possible involvement of lectins in the aggregation of cell organelles was previously suggested (Pak et al 1991, Kim et al 2001, 2002, Klotchkova et al 2003 and three lectins (Bryohealin, BPL-2, and BPL-3) were isolated in this species (Yoon et al 2008, 2011.For the successful aggregation of cell organelles during protoplast formation in B. plumosa, the existence of additional lectins was suggested (Kim et al 2006, Han et al 2011. In this study, we describe the biochemical and molecular characterization of another lectin from B. plumosa, BPL-4, which might also be involved in the protoplast regeneration of this species.…”

“…Lectinbased cell-cell recognition systems have been proposed in many algal groups and in some cases the corresponding lectins have been isolated. However, the number of characterized lectins is still considered too small (Yoon et al 2008, Han et al 2011.…”

“…Lectinbased cell-cell recognition systems have been proposed in many algal groups and in some cases the corresponding lectins have been isolated. However, the number of characterized lectins is still considered too small (Yoon et al 2008, Han et al 2011.Marine green alga Bryopsis plumosa (Hudson) Agardh possesses unique ability to regenerate new functional cells from small droplets of protoplasm extruded in seawater (Kim et al 2001). When protoplasm is released in the seawater, the organelles aggregate in vitro and form protoplasts.…”

“…Equilibrated strip was inserted onto SDS-PAGE gel (7 × 7 cm, 15%) and run at 200 V, 20 mA constant. The gels were stained with Coomassie brilliant blue R-250 as described by Han et al (2011). …”

Functional Expression and Characterization of the Recombinant <em>N</em>-acetyl-glucosamine/<em>N</em>-acetyl-galactosamine-Specific Marine Algal Lectin BPL3

“…For example, lectins are a potential diagnostic molecule for carbohydrate profiling on cell surfaces [2] and can be used for the sciences [11]. These sequence analyses also suggest that BPL3 is an example of parallel evolution across species boundaries.…”