DdeL, a novel thermostable lectin from Dypsis decaryi seeds: Biological properties

ABSTRACT A novel thermostable lectin, called DdeL, was obtained from the extract of Dypsis decaryi seeds. The extract of the tegument had the highest specific hemagglutination activity (196.03 HA/mg) when subjected to 70% acetone precipitation and purification on Superdex G-75 and exhibited a single peak (38.8 kDa). DdeL, a glycoprotein, had agglutinated blood types and was inhibited only by glycoproteins (albumin, azoalbumin and azocasein). Biochemical properties showed higher activity at acid pH (pH 5-6) than alkaline pH and activity was observed at all temperatures (up to 100 °C). DdeL exhibited bacteriostatic activity against Providencia stuartii and Staphylococcus aureus ATCC 29213, which presented minimum inhibitory concentration (MIC) of 750.0 μg/mL. When tested against fungi Sporotrichum schenckii and Candida albicans showed excellent MIC50 at 0.52 and 2.06 μg/mL, respectively. DdeL showed no cytotoxic effect on macrophages (J774.A1) and renal embryonic cells (HEK-293). In vitro acaricide activity of DdeL against Rhipicephalus showed high activity in low concentration. Therefore, we conclude that DdeL may be of interest for potential biotechnological applications.