Lectins are sugar-binding
proteins which are highly specific for their sugar
moieties. They typically play a role in biological recognition phenomena involving cells and proteins. For example, some bacteria use lectins to attach themselves to the cells of the host organism during infection.
The name ‘lectin’ is derived from the Latin word legere, meaning ‘to select’.
Although they were first discovered more than 100 years ago in plants, they are now known to be present throughout nature.
It is generally believed that the earliest description of such a hemagglutinin was by Peter Hermann Stillmark in his doctoral thesis presented in 1888 to the University of Dorpat, (one of the oldest universities in czarist Russia). This hemagglutinin, which was also highly toxic, was isolated by Stillmark from seeds of the castor tree (Ricinus communis) and was named ricin.
