The New Member of OAAH-Family Lectins from the Cultivated Red Alga Eucheuma denticulatum in Vietnam

the red alga, <i>Eucheuma denticulatumi</i> is an economically important food species and extensively cultivated in Vietnam. In this study, complementary DNA (cDNA) cloning based on the rapid amplification of cDNA ends (RACE) methods elucidated the full-length sequence of a new lectin-like protein (named EDL) from this alga. The cDNA cloning of the lectin-like protein encoded a polypeptide of 268 amino acids including an initiating methionine. The deduced amino acid sequence of lectin-like protein composed of four tandem repeated domains of about 67 amino acids and sharing 45% sequence identity. The primary structure of the lectin-like protein, EDL, highly resemble those of the anti-virus and anti-cancerhigh-mannose N-glycan specific lectins in lower organisms including <i>Oscillatoria agardhii</i> NIES-240 (OAA) from cyanobacterium, <i>Burkholderia oklahomensis</i> EO147 (BOA), <i>Myxococcus xanthus </i>(MBHA) and <i>Pseudomonas fluorescens</i> Pf0-1 (PFL) from proteobacteria, <i>Eucheuma serra</i> (ESA-2), <i>E. denticulatum</i> (EDA-2), <i>Kappaphycus striatus</i> (KSA-1 and KSA-2), <i>K. alvarezii </i>(KAA-1 and KAA-2) and <i>Solieria filiformis</i> (SfL-1 and SfL-2) from carrageenophyte red algae. The high resemblance in structure with anti-virus and anti-cancer lectins suggests that the cultivated red alga <i>E. denticulatum</i> could also be a good source of functional protein (lectin) for application