Ac-AP-12, a novel factor Xa anticoagulant peptide from the esophageal glands of adult Ancylostoma caninum

Immunoscreening an Ancylostoma caninum cDNA library with canine hookworm-infected dog serum resulted in the isolation of a 461 bp cDNA encoding Ac-AP-12, a new 9.1 kDa anticoagulant peptide (100 amino acids) with 43-69% amino acid homology to other nematode anticoagulant peptides (NAPs) from Ancylostoma hookworms. Messenger RNA transcription and expression of Ac-AP-12 was unique to the adult stage of A. caninum. The yeast expressed recombinant Ac-AP-12 demonstrated potent anticoagulant activity on human blood plasma in a concentration dependent manner, and was shown to specifically inhibit human factor Xa activity. Immunolocalization with specific rabbit antiserum showed that Ac-AP-12 was exclusively located in the esophageal glands of adult hookworm. Ac-AP-12 is hypothesized to facilitate both parasite blood feeding and digestion.

Ac-AP-12, an anticoagulant peptide with 9.1 kDa produced by Ancylostoma caninum esophageal glands (es) exhibits potent anticoagulant activity (aPPT, PT) by inhibiting human fXa.139Research highlights► A novel anticoagulant peptide (Ac-AP-12) was cloned from Ancylostoma caninum. ► The recombinant protein demonstrated potent anticoagulant activity on human blood. ► It specifically inhibited human fXa activity. ► Immunolocalization showed its location at esophageal glands of adult hookworm. ► It may play an important role in the blood feeding and digestion.