Secreted proteases of the fungal necrotroph Botrytis cinerea. A. Gelatin/SDS-PAGE zymogram showing two protease (gelatinase) bands, pre-incubated or not with class-specific protease inhibitors before electrophoretic separation. Ctrl, control sample, with no inhibitor added; SBTI, soybean trypsin inhibitor; E-64, trans-epoxysuccinyl-L-leucylamido-(4-guanidino) butane; CYS, oryzacystatin. Rf values on the right refer to relative mobilities in the gel, compared to the protein stain front (arbitrary value of 1.00). B. Elution pattern of B. cinerea secreted Asp proteases affinity-purified with pepstatin-agarose beads. The protein extract was passed through a 3-ml pepstatin A-agarose column, and the bound proteases eluted by pH increase at 8.2. The elution fractions were monitored for azocaseinase activity and sensitivity to pepstatin inhibition (see text for details). The relative inhibitory effects of pepstatin on crude (non-purified) and pepstatin-enriched samples are shown in the inset graph. Data are expressed as relative inhibitory activities compared to a non-inhibited control (0% inhibition). Each bar is the mean of three independent values ± SE.
Munger et al. BMC Plant Biology 2012 12:198 doi:10.1186/1471-2229-12-198