The RT-PCR analyses further indicate that the expression of the z

The RT-PCR analyses further indicate that the ZD1839 mw expression of the zearalenone lactonohydrolase gene is subject to different modes of regulation

in examined isolates. In particular, for the isolate AN 171, two hours after the toxin administration, a significant increase in the zearalenone lactonohydrolase expression is noted, suggesting that in T. aggressivum the presence of zearalenone in the medium directly activates expression of the gene. Further study of sequence variation in lactonohydrolase genes is planned, with redesign of PCR markers based on sequenced regions and extension into non-coding regions of transcript (5′-UTR) [11] using RACE-PCR. Subsequent research will also encompass separation and identification of end products for detoxification process, as well as isolation of MK0683 datasheet enzyme protein using Western blot. Previous works have confirmed the existence and function of zearalenone – specific lactonase in Clonostachys sp. (old name of Gliocladium sp.) [9]. The enzyme is one of Selleck MX69 the

reasons Clonostachys growth is not inhibited by zearalenone. We posit that presence of functioning homologues within Trichoderma can also contribute to their effective antagonistic activity [19], against zearalenone-producing F. culmorum and F. graminearum (and possibly other resorcyclic acid lactone producers). Mechanistic features of catalytic site involved in zearalenone biotransformation ability are shown

to be evolutionarily old, likely predating the split between Leotiomycetes and Sordariomycetes (barring horizontal transfer between fungal hosts). While it is unlikely that the exact function of distant homologs is the same, the affinity towards large hydrophobic epoxides and conservation of catalytic Decitabine clinical trial mechanism (as evidenced by active site superposition – Figure 7) are likely. Presence of several conserved arginines within the cap domain raises possibility of their involvement in substrate binding or orientation (coupled with conformational change), analogous to the mechanisms observed previously in dienelactone hydrolase [20] and 3-oxoadipate enol lactonase [16]. Elucidation of the full substrate orientation/catalysis scenario (including involvement of the glutamate and aspartate residues and their spatial conformations during the process) is planned through application of molecular dynamics experiments for modelling of the ligand binding process. Notably, according to previously published work on B. ochroleuca enzyme [11] ZEN was rapidly replaced with conversion product. The mass of the molecular ion (M + 1) corresponding to this product was 293. In our analysis, we did not register the corresponding peak, either due to differences in protocol or because of another mechanism of zearalenone decomposition.

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