LECTINS

• Lectins are proteins or glyco-proteins of non-immune origin.
• Discovered in castor beans.
• Identified based of lectin affinity chromatography (LAC)/ histochemical methods.
• Lectins function as: Allergens and haemagglutinins.

Ubiquitous distribution (plants, virus, fungi, bacteria, insects, animals and humans)
Bind selectively with involvement of enzymes specific for carbohydrate ligands.

• Functioning of lectins: Based on the reaction of glycosylation.
• In vertebrates, lectins are connected with cell recognition, proliferation control, adhesion, differentiation, mechanism of organ creation and defense mechanism.

Bind reversibly with carbohydrate structures.
Different stages of physiological and pathological development of human organs and organ systems.


Classification: 3 types
1. Mero-lectin
2. Holo-lectin
3. Chimer-lectin

Based on carbohydrate binding specificity: 
Mannose-mannose
Glucose
Galactose-galactose
Fucose
Sialic acid binding lectins

Uses:
1. Anti H-antigen: Ulex europeus (Bombay blood group)
2. Anti A1 lectin: Dolichos biflorus (A1 group).

Can be used as
Blockers of pathogens
Immune stimulants
Hormone modulators
Natural insecticides
Drug carriers