Objective To investigate the effects of airborne fine particulate matter(PM2.5) on anti-oxidative enzymes activities and lipid peroxidation levels in livers, spleens, and kidneys of rats. Methods 32 male Wistar rats were randomly divided into PM2.5 exposure groups of different concentration (1.5, 7.5, 37.5 mg/kg), exposed by tracheoperfusion and control group treated with physiological saline. Rats were killed 24 h after treatment, and the levels of thiobarbituric acid reactive substance (TBARS), glutathione(GSH) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) were determined. Results PM2.5 exposure caused significantly decrease of SOD, CAT, GSH-Px, SOD/TBARS in livers and kidneys in a dose-dependent manner compared with control group (P

AIM:To construct eukaryotic expression plasmids encoding Sox2 and Sox2 K247R and identify their expression and SUMOylation. METHODS: With gift plas-mid encoding Sox2 gene as a template, Sox2 K247R was obtained by overlapping extension PCR, followed by construction of pCMV-HA-Sox2 and pCMV-HA-Sox2 K247R. After enzyme digestion analysis and DNA sequencing, these two constructs were transfected or co-transfected with pC-MV-Myc-SUMO1 into 293 FT cells by lipofectin method. Western blot was employed to analyze expression and SUMO ylation of Sox2. RESULTS: It was revealed that eukaryotic expression vectors were constructed with correct sequence, where in mutant Sox2, the AAG codon was switched to CGG codon. Western blot results showed that good expression of both wt and mut Sox2, of which the latter could not be modified by SUMO1. CONCLUSION: Successful construction and expression of Sox2 and Sox2 K247R. Sox2 could be SUMO lyated in vitro but Sox2 K247R not.

Genetically encoded Ca(2+) indicators (GECI) are important for the measurement of Ca(2+) in vivo. GCaMP2, a widely-used GECI, has recently been iteratively improved. Among the improved variants, GCaMP3 exhibits significantly better fluorescent intensity. In this study, we developed a new GECI called GCaMPJ and determined the crystal structures of GCaMP3 and GCaMPJ. GCaMPJ has a 1.5-fold increase in fluorescence and 1.3-fold increase in calcium affinity over GCaMP3. Upon Ca(2+) binding, GCaMP3 exhibits both monomeric and dimeric forms. The structural superposition of these two forms reveals the role of Arg-376 in improving monomer performance. However, GCaMPJ seldom forms dimers under conditions similar to GCaMP3. St ructural and mutagenesis studies on Tyr-380 confirmed its importance in blocking the cpEGFP β-barrel holes. Our study proposes an efficient tool for mapping Ca(2+) signals in intact organs to facilitate the further improvement of GCaMP sensors.
Calcium ; chemistry ; metabolism ; Calmodulin ; chemistry ; genetics ; metabolism ; Crystallography, X-Ray ; Dimerization ; Green Fluorescent Proteins ; chemistry ; genetics ; metabolism ; Histidine ; chemistry ; genetics ; metabolism ; Hydrogen-Ion Concentration ; Myosin-Light-Chain Kinase ; chemistry ; genetics ; metabolism ; Peptide Fragments ; chemistry ; genetics ; metabolism ; Protein Structure, Tertiary ; Recombinant Fusion Proteins ; biosynthesis ; chemistry ; genetics