During his years in Birmingham and Edinburgh, John Berry Haycraft had been actively engaged in research and published papers on the coagulation of blood, and in 1884, he discovered that the leech secreted a powerful anticoagulant, which he named<unk> , although it was not isolated until the 1950s, nor its structure fully determined until 1976. Full length<unk>  is made up of 65 amino acids. These amino acids are organized into a compact N-terminal domain containing three disulfide bonds and a C-terminal domain that is completely disordered when the protein is un-complexed in solution. Amino acid residues 1-3 form a parallel beta-strand with residues 214-217 of thrombin, the nitrogen atom of residue 1 making a hydrogen bond with the Ser-195 O gamma atom of the catalytic site. The C-terminal domain makes numerous electrostatic interactions with an anion-binding exosite of thrombin, while the last five residues are in a helical loop that forms many hydrophobic contacts. Natural<unk>  contains a mixture of various isoforms of the protein. However, recombinant techniques can be used to produce homogeneous preparations of<unk> .
Hirudin
Bivalirudin
Lepirudin
Argatroban
Palladin
Anistreplase
Tinzaparin sodium
Lusutrombopag