A fungal enzyme with the ability of aflatoxin B1 conversion: Purification and ESI-MS/MS identification

Armillariella tabescens, a Chinese edible and medicinal fungus, whose multienzyme exist ability of AFB1-converting, and ADTZ (aflatoxin-detoxizyme) had previously purified from the A. tabescens multienzyme monitored by AFB1 conversion. However, the enzyme now confirmed an oxidase and renamed aflatoxin-oxidase (AFO). In this paper, AFO was purified by an economical and practical three-step procedure monitored by AFB1 conversion. And ESI-MS/MS analysis was done for identification of AFO. The following database searching (Protein Blast on NCBI) results did not show any homologous oxidase protein, which implied that AFO was mostly a new oxidase differing from other reported aflatoxin-converting enzymes such as fungal laccase and horse radish peroxidase. HPTLC analysis of the purified AFO activity suggested that the enzyme reacted at the bisfuran ring of AFB1 which was the key toxic structure. Therefore, all these investigations implied a new choice for biodegradation of aflatoxin in foods and feeds with the practical application of AFO.