Cloning and characterization of a microsomal aminopeptidase from the intestine of the nematode Haemonchus contortus

Proteases in Blood-Feeding Nematodes and Their Potential as Vaccine Candidates

“…Analyses have shown that the major N-linked glycans found in H11 had up to three fucose residues attached to chitobiose cores, structures which are predicted to be highly immunogenic in mammals. 22 These carbohydrates may contribute to the protective immune responses stimulated by vaccination with gut-expressed glycoproteins. Indeed, as noted earlier, a considerable component of the IgG response in lambs immunised with H-gal-GP is directed against the glycan component.…”

“…It is a highly effective immunogen (90% reductions in faecal egg output, 75% reduction in worm burden) against H. contortus challenge 18 DQG SURWHFWLRQ LV FORVHO\ FRUUHODWHG ZLWK VSHFL¿F V\VWHPLF ,J* WLWUHV WR + 21 cDNA cloning and sequence analysis showed that H11 was an aminopeptidase 22 and has several isoforms 18 + WR + 7KH QDWLYH IRUP RI + SXUL¿HG E\ OHFWLQDI¿QLW\ chromatography, comprises a mixture of these isoforms and both aminopeptidase A and M-type activities. 18 The isoforms have a short N-terminal cytoplasmic tail, a transmembrane region and an extracellular region organised into four domains.…”

“…Several experiments 18 suggested that protection was not necessarily dependent on inhibition of enzyme activity. Glycan PRGL¿FDWLRQ ZDV FRQVLGHUHG FHQWUDO WR WKH H[SUHVVLRQ RI SURWHFWLYH LPPXQLW\ JLYHQ WKDW native H11 possesses highly immunogenic and novel N-linked glycans 22 which are quite distinct from glycans expressed by insect cells. Worms recovered from sheep immunized with native H11 have a coating of sheep antibody bound to the worm gut surface, whereas those recovered from sheep immunized with baculovirus H11 do not; 17 an observation which could be ascribed to the differing glycan components in the two vaccines.…”

Comparative immunoprophylactic efficacy of Haemonchus contortus recombinant enolase (rHcENO) and Con A purified native glycoproteins in sheep

“…1. The glycoproteins of Con A eluted fraction was identical to the H-gal GP complex and H11 (Newton and Munn, 1999;Smith et al, 1999), it consists of >250 kDa, 150 kDa, 110 kDa, 55 kDa and 25 kDa proteins which are the family of H-gal GP complex and aminopeptidase (Smith et al, 1997).…”

Cloning and sequence analysis ofHemonchus ContortusHC58cDNA

“…Vaccination may be the ultimate, effective and sustainable strategy for controlling this parasite. Some protein antigens have been tested for protection against H. contortus including H11 (Smith et al 1997), H-gal-GP ) and cysteine proteases . Different types of proteases have been extensively reviewed (Sajid and Mckerrow 2002).…”