Lectins

Part of speech: noun

Definitions

1. Proteins that bind specifically to certain sugar molecules on cell surfaces or in organisms
2. Biomolecules that attach selectively to carbohydrate structures and often mediate cell recognition or signaling
3. Molecules that selectively adhere to sugars, playing roles in cellular interactions and immune processes

Etymology: Lectins were named in 1954 by the immunochemist W.C. Boyd, who needed a label for a class of proteins that seemed to bind sugars the way antibodies bind antigens. He built the word from the Latin "lēctus," meaning "chosen," with the suffix "-in," the standard ending for proteins, which is why the name reads like a chemical's ID rather than a poetic coinage. The idea was that these proteins selectively pick out particular sugars. The Latin root gives the name its logic. "Lēctus" is the past participle of "legere," "to choose" or "to gather," the same root behind English "select," "elect," and "eclectic." A lectin, then, is named for its selectivity: it chooses one sugar over others. The root is shared with words for gathering and picking, which is a nice fit for a molecule that is defined by what it grabs.