Purification and partial characterization of seed lectins from Vicias belonging to subgenus Vicilla section Cracca

Purification and characterization of a synergistic bioactive lectin from Pleurotus flabellatus (PFL-L) with potent antibacterial and in-vitro radical scavenging activity

Lectin is a carbohydrate-binding protein, which exhibits a plethora of biological properties such as antimicrobial, antifungal, and anticancer activities. In the present study, lectin, with an antibacterial and antioxidant potential, was purified from the oyster mushroom Pleurotus flabellatus. The P. flabellatus Lectin (PFL-L) was purified by using a DEAE - cellulose anion exchange chromatography followed by gel-filtration chromatography. The PFL-L was characterized by CD, HPLC, and MALDI-TOF/MS. The purity of PFL-L increased to 62.40% with the recovery of hemagglutinating activity (HA) by 12.12%. On SDS - PAGE, the PFL-L gave a single band of 18 kDa. PFL-L, consisting of d-galactose, exhibits a strong hemagglutinating activity. It was stable at pH (6.0-7.5) and temperature (10-20 °C) in addition to having extensive hemagglutinating activity. PFL-L enhanced the HA with the use of different metal ions namely Mg²⁺, Ca^2+, and Fe²⁺. The study of bacterial growth inhibition led to the inference that the PFL-L was more potent against gram-negative bacteria. PFL-L showed the highest radical scavenging activity for the DPPH assay at 100 μg/mL (89.9 ± 2.53%). The highest antioxidant activities with IC₅₀ values (for DPPH assay) of 53.96 μg/mL were determined for PFL-L and the present study shows that lectin from P. flabellatus manifested distinctive character and potentially exploitable activities.

A review of Vicieae lectins studies: End of the book or a story in the writing?

Vicieae tribe, Leguminosae family (Fabaceae), has been extensively studied. In particular, the study of lectins. The purification, physicochemical and structural characterizations of the various purified lectins and the analysis of their relevant biological activities are ongoing. In this review, several works already published about Vicieae lectins are addressed. Initially, we presented the purification protocols and the physicochemical aspects, such as specificity for carbohydrates, optimal activity in the face of variations in temperature and pH, as well metals-dependence. Following, structural characterization studies are highlighted and, finally, various biological activities already reported are summarized. Studies on lectins in almost all genera (Lathyrus, Lens, Pisum and Vicia) are considered, with the exception of Vavilovia which studies of lectins have not yet been reported. Like other leguminous lectins, Vicieae lectins present heterogeneous profiles of agglutination profiles for erythrocytes and other cells of the immune system, and glycoproteins. Most Vicieae lectins consist of two subunits, α and β, products of a single precursor protein derived from a single gene. The differences between the isoforms result from varying degrees of proteolytic processing. Along with the identification of these molecules and their characteristics, biological activities become very relevant and robust for both basic and applied research.

Purification, Characterization, and Antiproliferative Activity of a Single-Chain Lectin from Vicia palaestina (Fabaceae) Seeds

Vicia palaestina Boiss. is an annual herb that grows in dry areas of eastern Mediterranean countries. It belongs to section Cracca subgenus Vicilla, which is characterized by having a high content in the non-protein amino acid canavanine. The seeds from some of these vetches are also rich in lectins. The purification and characterization of a single-chain lectin from the seeds of V. palaestina is described here. This lectin was the most abundant protein in albumin extracts. It has affinity for the glycoconjugate N-acetylgalactosamine and inhibits proliferation of the cancerous Caco-2 and THP-1 cell lines. In addition to their high nutritional value, the seeds from V. palaestina represent a source of lectins with health promoting and pharmacological potential because of their antiproliferative activity.