Lectins from plant and animal - Carbohydrate specificity: Unity in diversity and diversity in unity

Lectins, cell agglutinating, sugar binding proteins of nonimmune origin are omnipresent in all forms of living matter including viruses and bacteria. Their unique property to bind with carbohydrates leads them to use in the widened area of biological sciences including medicine. Multiple lectins often occuring in the same source have varying carbohydrate specificity. Some lectins preferably show binding specificity with oligosaccharides. Identical specificity of the lectins belonging to different families is a unique feature of plant lectins while C-Type lectins, a major group of animal lectins from diverse sources exhibit very less resemblance in their carbohydrate specificity. A limited diversity in carbohydrate specificity has been observed in S-Type lectins, galectins.