Purification and characterization of a glutathione S-transferase from the fungus Cunninghamella elegans

Cunninghamella elegans grown on Sabouraud dextrose broth had glutathione S- transferase (GST) activity. The enzyme was purified 172-fold from the cytos olic fraction (120000 X g) of the extract from a culture of C elegans, usin g Q-Sepharose ion exchange chromatography and glutathione affinity chromato graphy. The GST showed activity against 1-chloro-2.4-dinitrobenzene, 1,2-di chloro-4-nitrobenzene. 4-nitrobenzyl chloride. and ethacrynic acid. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel filtration chromatog raphy revealed that the native enzyme was homodimeric with a Subunit of M-r 27000. Comparison by Western blot analysis implied that this fungal GST ha d no relationship with mammalian alpha-, mu-, and pi -class GSTs. although it showed a small degree of crossreactivity with a theta -class GST. The N- terminal amino acid sequence of the purified enzyme showed no significant h omology with other known GSTs. (C) 2001 Federation of European Microbiologi cal Societies. Published by Elsevier Science B.V. Alt rights reserved.