Helminth glutathione S-transferase (GST)

Helminth glutathione S-transferases (GSTs) are a diverse group of enzymes that play a pivotal role in the survival and persistence of parasitic worms, such as schistosomes and nematodes, within their definitive hosts (PMID: 15708012). These enzymes primarily facilitate the detoxification of various electrophilic substances by catalyzing their conjugation to reduced glutathione, thereby neutralizing potential cellular damage from metabolic waste and host immune responses. Beyond detoxification, helminth GSTs are involved in antioxidant defense mechanisms that protect the parasite from host-generated reactive oxygen species and serve as ligandins for the transport of hydrophobic molecules like heme and fatty acids (UniProt: P09488). Due to their essential nature in maintaining the parasite's internal redox balance and protecting against host immunity, GSTs are considered high-priority targets for anthelmintic therapies and vaccine development. For example, the Sh28GST protein is the basis for the Bilhvax vaccine, which has undergone clinical trials to reduce the morbidity associated with urinary schistosomiasis by inducing antibodies that inhibit the enzyme's activity (PMID: 22435075). Inhibiting these enzymes or using them as immunogens disrupts the parasite's ability to manage oxidative stress, ultimately leading to reduced parasite viability, fecundity, and host tissue pathology.

Other names

Parasite glutathione S-transferaseHelminth GSTGlutathione transferaseSm28GSTSh28GSTSj26GST

Inhibition of the enzyme's catalytic activity prevents the detoxification of metabolic byproducts and host-derived oxidants, leading to parasite cellular damage. As a vaccine antigen, it induces neutralizing antibodies that block the enzyme's active site and promote antibody-dependent cell-mediated cytotoxicity (ADCC) against the parasite.