Molecular docking studies and in vitro degradation of four aflatoxins (AFB(1), AFB(2), AFG(1), and AFG(2)) by a recombinant laccase from Saccharomyces cerevisiae

Here, molecular docking simulation was used to predict and compare interactions between a recombinant Trametes sp. C30 laccase from Saccharomyces cerevisiae and four aflatoxins (AFB(1), AFB(2), AFG(1), and AFG(2)) as well as their degradation at a molecular level. The computational result of docking simulation indicates that each of the aflatoxins tested can interact with laccase with a binding ability of AFB(1)>AFG(2)>AFG(1)>AFB(2). Simultaneously, it also demonstrated that aflatoxin B-1? B-2? G(1)? G(2) may interact near the T1 copper center of the enzyme through H-bonds and hydrophobic interactions with amino acid residues His481 and Asn288; His481(sic) Asn288, and Asp230; His481 and Asn288. Biological degradation test was performed in vitro in the presence of a recombinant laccase. Degradation increased as incubation time increased from 12 to 60 hr and the maximum degradation obtained for AFB(1), AFB(2), AFG(1), and AFG(2) was 90.33%, 74.23%, 85.24%, and 87.58%, respectively. Maximum degradation of aflatoxins was determined with a total activity 3 U laccase at 30 degrees C in 0.1 M phosphate buffer, pH 5.7 after 48-hr incubation. The experimental results are consistent with that of docking calculation on the biological degradation test of four aflatoxins by laccase. Practical Application In this study, the degradation efficiencies of laccase for B and G series of aflatoxins were determined by computer simulation and verified by performing in vitro experiments. It can provide reference for rapid screening of aflatoxin degradation-related enzymes.