Fig 2. Zn²⁺-contents of Fur family proteins from B. licheniformis.

(A) Purified Fur family proteins from B. licheniformis. B. licheniformis Fur-like proteins were purified after overexpression in E. coli, and analyzed by SDS-PAGE after alkylation by iodoacetamide. (B) H₂O₂-dependent Zn²⁺-release. Release of Zn²⁺ from proteins (5 μM) was measured by monitoring Zn²⁺-PAR complex at 494 nm every 1 sec for 30 min after treatment of 0, 1, 10, and 100 mM H₂O₂. Data for experiments with 100 mM H₂O₂ are only shown for clarity. The Zn²⁺-content of proteins was calculated using a molar extinction coefficient of 85,000 M^-1cm^-1 at 494 nm for Zn²⁺-PAR complex.