Variable expression of glutathione S-transferase isoenzymes in the fungus, Mucor circinelloides

Mucor circinelloides (previously M. javanicus) variably expresses two isoenzymes of glutathione S-transferases. Glutathione S-transferases 1 and 2 were purified by affinity chromatography and found to be dimers with subunit M(r) values of 25.5 and 28. While glutathione S-transferase 1 immunoblotted with rat glutathione S-transferase T 5-5, N-terminal sequencing indicated that this enzyme was distinct from recently characterised bacterial and fungal glutathione S-transferases and did not readily fit into any one class. It showed some similarity to several classes including insect class II and plant type III. M. circinelloides glutathione S-transferase 2 did not immunoblot and yielded no N-terminal sequence. Copyright (C) 1999 Federation of European Microbiological Societies.