Oligonucleotide molecules that bind (i.e., “stick to”) other, specific molecules (e.g., proteins). Aptamer is from the Latin aptus (“to fif). For example, in 1992, Louis Bock and John Toole isolated aptamers that bind and inhibit the blood-coagulation enzyme, thrombin. Since thrombin is crucial to the formation of blood clots (coagulation), such aptamers may be useful for anticoagulant therapy (e.g., to prevent blood clots following surgery or heart attacks).
A chemical, usually a protein or a nucleic acid, that can fashion itself into numerous shapes, e.g., the configuration of a cell surface receptor.