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NQO1 and NQO2 are closely related quinone reductases, which are FAD-linked enzymes that catalyze the 2-electron reduction of quinones. Whereas NQO1 has a well-defined role in cellular detoxification of quinones, NQO2’s function is less clear; it uses the conventional cofactors NADH/NADPH inefficiently compared to smaller nicotinamide cofactors, which are often present in low cellular amounts. This unique cofactor specificity suggests that NQO2 may have non-enzymatic functions, such as a role in intracellular signalling. The goals of this research project include: 1) examining whether cofactor specificity is conserved in amniote NQO2 enzymes and 2) re-constructing ancient enzymes along the evolutionary pathway of NQO1 and NQO2 to determine the molecular origins of cofactor specificity differences. The reductive half-reactions of H.sapiens, A.platyrhynchos, and A.mississippiensis NQO2 with NADH were investigated using stopped-flow apparatus. With increasing NADH concentration, the observed rate constant for NQO2 reduction for all three amniotes increased before reaching saturation. This indicates that the enzyme-substrate complex for NQO2 reduction exists in rapid equilibrium, leading to the conclusion of non-productive NADH binding across all amniote NQO2s. To examine the evolution of NQO1 and NQO2, a phylogenetic tree was created using amino acid sequences of numerous species. While the characterization of ancient enzyme kinetics is still ongoing, the successful expression of various ancestral proteins confirmed our analysis of the phylogeny and predicted sequences.

L-phenylalanine, L-tyrosine and L-tryptophan are aromatic amino acids that are widely used in industrial, agricultural and pharmaceutical applications. Currently, heterotrophic microorganisms are fed require an organic source of carbon to produce amino acids, photosynthetic bacteria are investigated. Mutagenesis by methyl methanesulfonate followed by selection on aromatic amino acid analogues produced mutants that are able to overproduce aromatic amino acids. Two mutant strains were investigated: TA1, which is a better L-phenylalanine overproducer, and 5FT1, which overproduces L-tryptophan. To test the influence of growth conditions on amino acid production, we grew mutant strains of Synechocytis sp. 6803 under enhanced CO2 or glucose-rich conditions. We quantified the amount of each aromatic amino acid synthesized intracellularly and transported to extracellular medium by high performance liquid chromatography. We analysed the transient production of the aromatic amino acids to see if it is a growth related process. If it is growth related, the recommended growth method would be a fed batch reactor or a turbidostat to keep the cells at the exponential phase. If it is not growth related, we would recommend to use a batch reactor to allow cells reach stationary phase and harvest after maximum production.

3D ordered silver nanoshell silica photonic crystal beads as a novel encoded surface enhanced Raman scattering substrate are proposed for the development of highly efficient multiplex bioassays.

Novel quantum-dot-tagged photonic crystal beads were fabricated for multiplex detection of tumor markers via self-assembly of quantum dot-embedded polystyrene nanospheres into photonic crystal beads through a microfluidic device.

Transgenic wheatgrass generated from hybrid wheatgrass (Agropyron cristatum × A.desertorum cv. ‘Hycrest-Mengnong’) were identified by PCR analysis and Southern blot. CBF4, the exogenous gene, a transcriptional factor which plays an active role in plant during drought adaptation and cold acclimation, was transferred into wheatgrass with phosphinothricin acetyltransferase conferring herbicide resistance as selection gene. Results of Northern blot assay displayed that exogenous gene CBF4 expressed at transcription level in transgenic plants. Further drought stress detection showed that drought tolerance of transgenic plants was enhanced.