Fig 3. ICP-MS quantification of iron in TaTFP wildtype and mutants.

Proteins (in 37.5 mM sodium acetate buffer, pH 5, with 6.25% (w/v) sucrose) were denatured and precipitated. The supernatant was subjected to ICP-MS. Iron was quantified based on calibration with Iron ICP Standard. OA, ovalbumin; Tf, holo-transferrin. Shown are means ± SD (N = 3 independent expression experiments).