SDS-PAGE analyses of SH preparations from cells, which were harvested after different cultivation times.

<p>Cells from strain SH2F (six-subunit SHvar2; 5′-StrepII tagged HoxI; HoxI*), cultivated under ‘optimized autoinduction conditions’, were harvested after 38 hours (lanes 1–3) and 44 hours (lanes 4–6) from the same culture. 1 gram of cells thus obtained was used for preparation of the cell-free extracts (lanes 1 & 4; 25 µg applied). Purification was carried out using a 1 mL StrepTactin Superflow® gravity flow column (lanes 2 & 5; 15 µg and 5 µg applied, respectively) and subsequently a Superdex 200 HR 10/300 gel filtration column for polishing (lanes 3 & 6; 4 µg and 5 µg applied, respectively). Notably, the HoxFUI₂ diaphorase module appears to be stable over time, while the HoxYH hydrogenase moiety dissociates from the complex after 38–44 hours of cultivation. Activities of the preparations after gel filtration: SH_{38 h}: 103 U·mg⁻¹; SH_{44 h}: 21 U·mg⁻¹. M = Protein marker.