title: Digestive proteases of blood-feeding nematodes.
abstract: Blood-feeding parasites employ a battery of proteolytic enzymes to digest the contents of their bloodmeal. Host haemoglobin is a major substrate for these proteases and, therefore, a driving force in the evolution of parasite-derived proteolytic enzymes. This review will focus on the digestive proteases of the major blood-feeding nematodes - hookworms (Ancylostoma spp. and Necator americanus) and the ruminant parasite, Haemonchus contortus - but also compares and contrasts these proteases with recent findings from schistosomes and malaria parasites. Haematophagous nematodes express proteases of different mechanistic classes in their intestines, many of which have proven or putative roles in degradation of haemoglobin and other proteins involved in nutrition. Moreover, the fine specificity of the relationships between digestive proteases and their substrate proteins provides a new molecular paradigm for understanding host-parasite co-evolution. Numerous laboratories are actively investigating these molecules as antiparasite vaccine targets.
authors.affiliation: Department of Microbiology and Tropical Medicine, George Washington University Medical Center, Washington DC 20037, USA.
authors.forename: Angela L
authors.initials: AL
authors.lastname: Williamson
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Brindley
authors.forename: David P
authors.initials: DP
authors.lastname: Knox
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hotez
authors.forename: Alex
authors.initials: A
authors.lastname: Loukas
mesh_terms: D000723:Ancylostomatoidea / Q000201:enzymology / Q000502:physiology; D000818:Animals; D010450:Endopeptidases / Q000378:metabolism*; D006189:Haemonchus / Q000201:enzymology / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism*; D006790:Host-Parasite Interactions; D006801:Humans; D009348:Nematoda / Q000201:enzymology* / Q000502:physiology; D013379:Substrate Specificity
chemical_list: D006454:Hemoglobins; D010450:Endopeptidases