Again, the highest oxygen evolving activities were recorded from HC grown cells and differences between the WT and the Δflv mutants were only minor.
Under LC, both Δflv2 and Δflv4 cells lost more of the PSII oxygen evolving activity during the high light illumination than WT (Figure 7).
After 90 min treatment, more than 80% of PSII oxygen evolving activity still remained in the WT, but only about 60% of PSII activity was left in Δflv2 and Δflv4.
The cells grown under 50 µmol photons m−2 s−1 at HC and LC were illuminated in a photobioreactor at 1500 µmol photons m−2 s−1 white light for up to 90 min, and the PSII activity was measured during the course of illumination by monitoring the oxygen evolving activity of the cells.
However, some investigators dispute that energy expenditure requirements have decreased [ 42, 43] which casts questions on the potential role that energy expenditure played in evolving activity regulation.
The last three amino acid residues, including leucin at position 246 (245 in spinach), were shown to be critical for binding to PSII and for restoration of oxygen evolving activity [ 47].
In search for the role of the FtsH protease we studied the UV-B induced damage in the oxygen evolving activity of PSII in the MFtsH mutant from which the slr0228 gene had deleted.
About 10% decrease in the photochemical efficiency (Fv/Fm) and the oxygen evolving activity of photosystem II (PSII) was measured after cold and light (hereafter, Cold/Light or C/L) treatment, but not after cold and dark (hereafter Cold/Dark or C/D) treatment (Table 1).
Modular natural products are attractive leads in drug discovery due to their evolved biological activities, but it is unclear which chemical similarity methods perform best in the chemical space occupied by their unique and complex scaffolds.
Although the number of approaches is still small, we observe a trend towards rigorous and highly creative assays that, however, often rely on the indirect detection of the evolved enzyme activities or host strains.
