Lectin from Phaseolus vulgaris (red kidney bean)

Lectins are carbohydrate-binding proteins, which contains four subunits with a molecular weight of 125 kDa. Leucoagglutinin PHA-L is a plant lectin, which is transported by the neurons in the central nervous system.

Lectin from Phaseolus vulgaris (red kidney bean) has been used:

• it has been used as a positive control to treat cells
• to stimulate cell culture for the analysis of lymphocyte proliferation
• to stimulate T cells

Lectin agglutinates cells and precipitates polysaccharides and glycoproteins. It is associated with toxic allergens and hemagglutinins. Lectin exhibits anti-cancer, anti-human immunodeficiency virus (anti-HIV) and anti-microbial infection properties. Lectin inhibits mucosal atrophy, lowers type 2 diabetes and obesity, enhances nutrient absorption and regulates drug targeting.

PHA consists of two molecular species, an erythroagglutinin (PHA-E) which has low mitogenic activity and high erythroagglutinin activity, and leucoagglutinin (PHA-L) which has high mitogenic and leucoagglutinating activity, but very low erythroagglutinating activity.
PHA-E is not blood group specific, but agglutination can be inhibited by certain oligosaccharides. PHA-P is the protein form of PHA prior to separation and purification of erythroagglutinin and leucoagglutinin. PHA-M is the mucoprotein form. Conjugates are prepared from the corresponding purified lectins.

Agglutination activity is expressed in μg/ml and is determined from serial dilutions of a 1 mg/ml solution. This activity is the lowest concentration to agglutinate a suspension of either human erythrocytes (2% in phosphate buffered saline, pH 6.8) or human leukocytes (10⁷ per mL in saline) after 1 hr incubation at 25 °C.