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 cytosolic fraction (120000 X g) of the extract from a culture of C elegans, using Q-Sepharose ion exchange chromatography and glutathione affinity chromatography. The GST showed activity against 1-chloro-2.4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene. 4-nitrobenzyl chloride. and ethacrynic acid. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel filtration chromatography revealed that the native enzyme was homodimeric with a Subunit of M-r 27000. Comparison by Western blot analysis implied that this fungal GST had 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 homology with other known GSTs. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. Alt rights reserved.