Purification and Characterization of AAVP, a Protein Inhibitor of TMV Infection, from the Edible Fungus, Agrocybe aegerita.

A protein with activity of inhibiting TMV infection on Nicotiana glutinosa, named AAVP, was isolated and purified from the fruiting bodies of edible fungus Agrocybe aegerita by precipitation of 40%--80% saturation of (NH(4))(2)SO(4) followed by DEAE-Fast Flow and S-200 column chromatography. The protein was proved to be homogeneous by SDS-PAGE and IEF. Analysis of the composition of amino acids showed that this protein contained no cysteine, poor in methionine and phenylalanine and rich in acidic and hydroxyl amino acids. The inhibition of TMV was 84.32% when the concentration of AAVP was 200 mg/L. N-terminus of this protein was blocked by pyroglutamyl, and the N-terminal sequence was QGVNIYNIVAGA. On potato-sucrose-agar medium, the purified protein did not inhibit the growth of three plant pathogen fungi, Trichoderma viride, Colletotrichum musae and Fusarium oxysporum.