No abstract

The present study aimed to produce and pathophysiologically evaluate the metallothionein (MT) fusion protein. A recombinant plasmid containing DNA segment coding the pET-glutathione transferase (GST)-small ubiquitin-related modifier (SUMO)-MT fusion protein was inserted into Escherichia coli for expression. The expression level of the fusion protein was very high, reaching to 38.4% of the total supernatant proteins from the organism. Subsequent filtration through glutathione Sepharose 4B gel and Sephadex G-25 yielded an MT fusion protein with purity more than 95%. When exposed to metals, E. coli containing the GST-SUMO-MT fusion protein showed an increased accumulation of Cd 2ϩ , Zn 2ϩ , or Cu 2ϩ at approximately 4.2, 4.0, or 1.6 times higher, respectively, than those containing the control protein. Administration of GST-SUMO-MT to mice that were also treated with D-galactose to induce neuronal and hepatic damage showed a significant improvement of animal learning and memory capacity, which was depressed in mice treated by D-galactose alone. Administration of MT fusion protein also prevented D-galactose-increased malondialdehyde contents and histopathological changes in the brain and liver. Furthermore, supplement of the fusion protein significantly prevented D-galactose-increased nitric oxide contents and -decreased superoxide dismutase activity in the brain, liver, and serum. The fusion protein was also able to prevent ionizing radiation-induced DNA damage of the mouse thymus. The present study indicates that GST-SUMO-MT has a normal metal binding feature and also significantly protects the multiple tissues against oxidative damage in vivo caused by chronic exposure to Dgalactose and by ionizing radiation. Therefore, GST-SUMO-MT may be a potential candidate to be developed for the clinical application.Metallothioneins (MTs) are a group of cysteine-rich proteins that ubiquitously present in the tissues of animals, plants, and microorganisms (Vasá k, 2005). MTs have highly conserved primary structures and similar spatial conformations. In mammals, four isoforms of MT exist: MT-I and MT-II are present in all tissues, whereas MT-III and MT-IV are present in brain tissues and keratinized epithelium, respectively (Theocharis et al., 2003;Vasá k, 2005). MTs not only are able to bind heavy metal ions and modulate trace mineral balance but are also able to protect tissues and cells from oxidative

Human acidic fibroblast growth factor (haFGF) stimulates repair and regeneration of central and peripheral nerves after various injuries. However, it is unable to cross the blood-brain barrier (BBB). To produce a therapeutic haFGF with cell-permeable activity, we fused the haFGF(19-154) gene with Tat-PTD. After its construction by a single-step insertion of a polymerase chain reaction (PCR)-amplified coding sequence, the vector pTat-haFGF(19-154)-His was expressed in Escherichia coli BL21 (DE3) cells. The optimal expression level of the soluble fusion protein was up to 36.7% of the total cellular protein. The recombinant Tat-haFGF(19-154)-His was purified by a combination of Ni-NTA affinity, Sephadex G-25, and heparin affinity chromatography to 95% as detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The final yield was 171 mg/l culture. Purified Tat-haFGF(19-154)-His had distinct mitogenic activity in Balb/c 3T3 cells, as measured by methylthiazoletetrazolium (MTT) assay and its ED(50) was 3.931 x 10(-4) micromol/l. Tat-haFGF(19-154)-His protein intravenously injected at the dose of 10 mg/kg could be detected in the pallium and hippocampi.

ABSTRACT. In China, Moschus berezovskii (forest musk deer), a firstclass national protected animal, was earlier widely distributed. However, wild populations of the forest musk deer have declined because of human activity and habitat loss. In order to gather useful information for its conservation and management, we investigated the genetic diversity and population structure of this species by analyzing a 632-bp fragment of mitochondrial DNA (mtDNA) control region in three wild populations in Shaanxi Province, China. The average A+T content (64.1%) of mtDNA was higher than that of G+C (35.9%). A total of 178 variable sites (about 28.03% of the total nucleotides in the sequence) were detected in 71 individuals. The nucleotide diversity (P I ) in the 71 individuals was 0.04688, and the average nucleotide differences (K) were 21.238. The 71 individuals belonged to 33 haplotypes according to the determined sequences. The average genetic distance (P) among the haplotypes of the species was 0.169. The phylogenetic tree constructed using the neighbor-joining method revealed that these individuals were clustered into three groups, but the individual distribution in those groups was disordered. These data indicated the variation and rich genetic diversity in the three populations of

A universal and robust strategy using polyurethane sponge as a precursor was developed to synthesize highly-soluble nitrogen-doped carbon quantum dots via a solvothermal method.