Keating Beach (nutgas68)
Superoxide dismutases (SODs) are the first line of defense against oxidative damage caused by reactive oxygen species and are associated with stress tolerance. Accordingly, many studies have focused on SODs, especially those from extreme habitats. In this study, we reported a novel Cu,Zn-SOD from the new species Benthodytes marianensis sp. nov (hereafter denoted as Bm-Cu,Zn-SOD) collected from the Mariana Trench. The purified recombinant enzyme with an approx. Mr. of 38 kDa was intracellular and dimeric, and it expressed activity at an optimal temperature of 30 °C and optimum pH of 7.4. The Km and Vmax values of Bm-Cu,Zn-SOD were 0.046 ± 0.004 mM and 1209.151 ± 24.057 U/mg, respectively. Under the tested conditions, Bm-Cu,Zn-SOD resisted interference from chemicals (β-mercaptoethanol and ethylenediaminetetraacetic acid), denaturants (urea and guanidine hydrochloride), and high salinity, showing high kinetic stability. Furthermore, Bm-Cu,Zn-SOD could be activated by high hydrostatic pressure. All these properties suggested adaptation to the deep-sea environment and thus indicated its potential future applications.In this study, inhibitory kinetics of Nuciferine and Methyl Ganoderate extrated from Lotus Leaves and Ganoderma lucidum on Mucor miehei Lipase were studied first. The molecular structure of Nuciferine and Methyl Ganoderate were determined. The inhibitory effects of two extracts on lipase were reversible, with the IC50 values of 0.194 and 0.332 mg/mL, respectively. The inhibition kinetic analysis by Lineweaver-Burk plots showed that they were a mixed-type inhibitor of lipase, with inhibition constants KI of 0.16 and 0.29 mg/mL, and KIS of 0.36 and 0.49 mg/mL, respectively. Results of spectral analysis showed that the UV absorption and the molecule fluorescence spectrum of the lipase hydrolyzate were significantly decreased after the inhibitor was added. The molecular docking further suggested that the interaction site between the active substance and inhibitor was located in an α-helix and a β-sheet of the lipase, and the lipase active site was interfered by the inhibitor near the cap structure. In addition, the proliferation and differentiation of 3 T3-L1 preadipocytes were inhibited by two extracts. Total triglycerides and cholesterol were significantly reduced in the cells. The results confirmed that Nuciferine and Methyl Ganoderate can be used as potential obesity treatment drugs.Rationally designed mutations on recombinant arginine deiminase (ADI) could act as a 'turn-off' L-arginine (L-Arg) fluorescent biosensor and provide an alternative method for rapid determination of L-Arg. Double mutations were introduced on the Cys251➔Ser251 and Thr265➔Cys265 of recombinant ADI, rendering a single cysteine present on the protein surface for the site-specific attachment of a fluorophore, fluorescein-5-maleimide. The double mutations on ADI (265C) and its fluorescein-labelled form (265Cf) conserved the catalytic efficiency of wild-type ADI. Upon binding to L-Arg, 265Cf induced structural conformational changes and rendered the fluorescein moiety to move closer to Trp264, resulting in fluorescence quenching. The duration of fluorescence quenching was dependant on the L-Arg concentration. A linear relationship between the time at the maximum rate of fluorescence change and L-Arg concentrations, which ranged from 2.5 to 100 μM, was found with R2 = 0.9988. Staurosporine The measurement time was within 0.15-4 min. Determination of L-Arg concentration in fetal bovine serum could be achieved by the standard addition method and without sample pre-treatment. The result showed a good agreement with the one determined by mass spectrometry, suggesting our biosensor as a promising tool for the detection of L-Arg in biological samples.Agarose is a potential wall material for encapsulation owing to its high oxygen barrier, but its high hydrophilia and low emulsifying activity restrict its application as a wall material for hydrophobic a
