Amino acid sequence of ghilanten: anticoagulant-antimetastatic principle of the South American leech, Haementeria ghilianii.

This study reports the amino acid sequence of ghilanten, an anticoagulant-antimetastatic principle of the hematophagous leech, Haementeria ghilianii. Ghilanten consists of 119 amino acids with twenty cysteines and a consensus sequence for heparin-binding at its carboxyl-terminus. Arginine-34 represents the reactive residue involved in the active-site inhibition of trypsin and Factor Xa. Immunoreactivity data suggest that heterogeneity among ghilantens is due in part to amino acid substitutions at their carboxyltermini.