FIG. 4.

Analysis of fluorescent derivatives of the MPT cofactor of R. capsulatus XDH. HPLC elution profiles of dephospho-form A isolated from Mocos of XDH from different R. capsulatus strains. (A) R. capsulatus KS36 (parental strains); (B) R. capsulatus R507 (moeA), grown in the presence of 1 mM molybdate; and (C) R. capsulatus R507 (moeA), grown without molybdate supplementation. Mocos were converted into form A by oxidation with iodine at 95°C. Dephospho-form A was eluted from a QAE-Sephadex column with 10 mM acetic acid and analyzed by HPLC. Fluorescence was monitored with excitation at 370 nm and emission at 450 nm. Each protein was used for the analysis at a concentration of 0.8 μM.