Botulinum neurotoxin type E heavy chain consists of two domains: N-terminal half as a translocation domain and C-terminal half (Hcc) as a binding domain. In this research a synthetic gene fragment encoding the binding domain of botulinum neurotoxin type E (BoNT/E-Hcc) was highly expressed in Escherichia coli by pGEX4T-1 vector. After purification, the recombinant BoNT/E-Hcc was evaluated by SDS-PAGE and western blot (immunoblot) analysis. Average yields obtained in this research were 3.7 mg recombinant BoNT/E-Hcc per liter of bacterial culture. The recombinant protein was injected in mice for study of its protection ability against botulinum neurotoxin type E challenges. The challenge studies showed that, vaccinated mice were fully protected against 10⁴ × minimum lethal dose of botulinum neurotoxin type E.

The bacterial enzyme tyrosinase, with its high oxidizing capacity, can be applied in phenolic biotransformation, pharmaceutical, cosmetics and textile industries. In this research, a native Bacillus sp.-producing tyrosinase was isolated from a soil sample. The strain was identified by morphological, biochemical and molecular tests using bioinformatics analysis, and was named Bacillus megaterium strain M36. According to the blast analysis of 16S rDNA (1434 bp), the strain showed 99% identity with Bacillus megaterium DSM319. The production of tyrosinase from the isolated strain was optimized by classic and response surface methods (RSM). The optimal conditions for tyrosinase production by the strain were determined to be as follow: growth temperature 36?C, pH of medium 7.0, incubation time 16 h, with medium containing 0.4 mg/mL L-tyrosine, 0.05% yeast extract, 0.423% tryptone, 3.4% NaCl and 148.4 ?M CuSO4. Results of experiments performed under the optimized condition showed an actual yield of 0.522 IU of enzyme, while the result under the initial conditions using basal medium (before optimization) gave 0.0312 IU of enzyme (16.7-fold increase). SDS-PAGE analysis showed that the tyrosinase enzyme from Bacillus megaterium strain M36 is about 34 kDa.

Escitalopram oxalate (EO) is considered as one of the extensively prescribed antidepressant drug in Turkey and some other countries, therefore this research was aimed to study the interaction of the drug with DNA and study of the substance effect on bacterial growth. The absorption value of the drug solution at 238 nm was increased when DNA was added gradually to it and it showed hyperchromism effect. The value obtained for DNA binding constant (Kb) was 0.035 M −1. When we added the CuCl2 2H2O to the mixture, any breakage was not shown in double strand DNA in comparison with control DNA. In addition low concentration of EO couldn’t protect DNA (0.5273 µmole bp) against Hydroxyl free radical (0.12 µmole) although it could protect the DNA when it was at the same or higher concentrations (0.5273, 5.273 and 252.73 µmole) than the DNA concentration. In addition, MIC of the drug for E.coli and Bacillus subtilis was almost 0.185 mM and 0.55 mM respectively. The E.coli strain was killed at concentrations 45, 15, 5 mM while the Bacillus subtilis was stable against all of the concentrations.

Flurbiprofen is non-steroidal anti-inflammatory drug which is commonly used for its analgesic, antipyretic, and anti-inflammatory effects. The purpose of the study was to explore the genotoxic and cytotoxic effects of flurbiprofen in human cultured lymphocytes by sister chromatid exchange, chromosome aberration, and cytokinesis-blocked micronucleus tests. 10, 20, 30, and 40 μg/mL concentrations of flurbiprofen (solvent is DMSO) were used to treatment of human cultured lymphocytes at two different treatment periods (24 and 48 h). Flurbiprofen had no significant genotoxic effect in any of these tests. But exposing to flurbiprofen for 24 and 48 h led to significant decrease on proliferation index, mitotic index, and nuclear division index (NDI). Also, all decreases were concentration-dependent (except NDI at 24 h treatment period). Consequently, the findings of this research showed that flurbiprofen had cytotoxic effects in human blood lymphocytes.

Keywords: Melanin, monophenolase, diphenolase, TLC