Determination of the role of the Carboxyl-terminal leucine-122 in FMN-binding protein by mutational and structural analysis.

Mutants of flavin mononucleotide-binding protein (FMN-bp) were made by site-directed mutagenesis to investigate the role of carboxyl-terminal Leu122 of the pairing subunit in controlling redox potentials, binding the prosthetic group, and forming the tertiary and quaternary structure. We compared the oxidation-reduction potentials, FMN-binding properties, and higher structures of wild-type FMN-bp and four mutant proteins (L122Y, L122E, L122K and L122-deleted). We found that the redox potentials were affected by mutations.

Efficient and rapid C-Si bond cleavage in supercritical water.

Arylsilanes, alkenylsilanes, allylic silanes, and alkylsilanes were found to undergo extremely facile and rapid C-Si bond cleavage in supercritical water. The rapid C-Si bond cleavage occurred even with robust unactivated tetraalkylsilanes. The control experiments revealed the dramatic difference between supercritical and subcritical conditions and that between supercritical water and supercritical methanol, attesting to a unique reactivity of supercritical water in C-Si bond cleavage.