During the past decade,
the molecular basis of this blood-feeding process and
the digestion has been partially identified as a cascade of
hemoglobinases [11]. After the worm takes up blood
into the intestine, the red blood cells are lysed by
hemolysin and hemoglobin is released. The released
hemoglobin is degraded and digested by a series of
hemoglobinases, initiating cleavage of the hemoglobin
molecule by an aspartic protease (APR) [12, 13],
followed by further digestion with several cysteine proteases
[10, 14] and metalloproteinases