Cathepsin B- and L-like cysteine protease activities during the in vitro development of Hysterothylacium aduncum (Nematoda: Anisakidae), a worldwide fish parasite.
Proteinases play an important role as virulence factors both in the life-cycle of parasites and in the pathogen-host relationship. Hysterothylacium aduncum is a worldwide fish parasite nematode which has been associated with non-invasive anisakidosis and allergic responses to fish consumption in humans. Cysteine proteinases have been associated with allergy to plant pollens, detergents and dust mites. In this study the presence of two types of cysteine proteinases (cathepsin B and cathepsin L) during in vitro development of H. aduncum is investigated. Specific fluorescent substrates were used to determine cathepsin activities. The activity detected with substrate Z-FR-AMC was identified as cathepsin L (optimum pH=5.5; range 3.5-6.5). Cathepsin B activity was only identified with Z-RR-AMC (optimum pH=7.0-7.5; range 5.0-8.0). The start of cultivation led to increased activity of both cathepsins (1.8-fold for cathepsin B and 6.3-fold for cathepsin L). These activities varied according to the developmental stage. Cathepsin B activity decreased after M4, returning to its initial level. Cathepsin L activity also decreased after M4, but still maintained a high level (4-6 times the initial level) in adult stages. Having considered these activity variations and the optimum pH values, we suggest that cathepsin L has a role in digestive processes while cathepsin B could be involved in cuticle renewal, among other possible functions.
Malagón
David
D
Departamento de Parasitología, Universidad de Granada, 18071 Granada, Spain.
Díaz-López
Manuel
M
Benítez
Rocío
R
Adroher
Francisco Javier
FJ
D000818:Animals; D017162:Ascaridida / Q000145:classification / Q000201:enzymology* / Q000254:growth & development*; D017191:Ascaridida Infections / Q000469:parasitology / Q000662:veterinary*; D002401:Cathepsin B / Q000378:metabolism*; D056668:Cathepsin L / Q000378:metabolism*; D057056:Cysteine Proteases / Q000378:metabolism; D005393:Fish Diseases / Q000469:parasitology; D015801:Helminth Proteins / Q000378:metabolism; D006790:Host-Parasite Interactions; D007814:Larva / Q000201:enzymology / Q000254:growth & development; D010473:Perciformes / Q000469:parasitology*
D015801:Helminth Proteins; D057056:Cysteine Proteases; D002401:Cathepsin B; D056668:Cathepsin L