Purification and characterization of an antitumor protein with deoxyribonuclease activity from edible mushroom Agrocybe aegerita

Scope Mushrooms are well known for their nutritional and medicinal value. Agrocybe aegerita has been used as a nutritious food around the world and for its herbal medicinal properties in Asia. In recent years, several antitumor proteins have been identified from A. aegerita. The objective of this study was to purify a novel antitumor protein from A. aegerita. Methods and results A novel antitumor protein A. aegerita deoxyribonuclease (AAD) was purified through a two-step chromatographic procedure and was shown to possess antitumor activity against different cancer cell lines. Cells treated with AAD produced typical apoptotic morphological changes, which include chromatin condensation, the accumulation of sub-G1 cells and caspase-8 cleavage. Biochemical characterization of AAD showed that it was a member of the DNase I family and that it possessed divalent metal ion-dependent endonuclease activity. The optimal temperature for AAD activity was 50 degrees C and its optimal pH was 8.5. The MS-identified peptides of AAD were found to match to Unigene3821, which has 97% homology with Aa-Pri1, in our A. aegerita transcriptome. Conclusion We have identified a novel antitumor protein from A. aegerita. This fuller understanding of A. aegerita would help us to enhance its use in nutritional and medical applications.