The histone-like protein HU is the most-abundant DNA-binding protein in bacteria.The HU protein non-specifically binds and bends DNA as a hetero- or homodimer, and can participate in DNA supercoiling and DNA condensation. It also takes part in DNA functions such as replication, recombination, and repair. HU does not recognize any specific sequences but shows a certain degree of specificity to cruciform DNA and repair intermediates such as nick, gap, bulge, etc. To understand the features of HU binding to DNA and repair intermediates, a fast and easy HU protein purification method is required. Here we report a two-step purification procedure of HU from Halobacillus karajensis (the gram positive and moderately halophilic bacteria isolated from Karaj surface soil). The method of HU purification allows obtaining a pure nontagged protein. Salting out and ion exchange chromatography were applied for purification, and the purified protein was identified by immunoblotting. Results showed that the molecular weight of the purified protein was approximately 11 kDa which is immunologically similar to the Bacillus subtilis HU protein (HBsu).

Background and Objective : The genus of sarcocystis, zonotic parasites, have two hosts in their life cycle. They have also special importance in industrial veterinary. The serological tests are the best methods for detection of the parasite. This research was planned for isolation of sheep sarcocystis specific protein for using in serological laboratory tests. Materials and Methods : The infected muscles of sheep carcass were collected from Tehran slaughter house and transferred to our laboratory. The sarcocystis were isolated from the infected muscles and crude antigen was prepared . The crude antigen was fragmented by serial dilution of ammonium sulfate solution and followed by size exclusion chromatography. Results: Crude antigen was electrophoresed by SDS-PAGE and its protein bands were detected by commassi brilliant blue staining. We used different concentrations of ammonium sulfate for precipitation and after by size exclusion chromatography, a 35kDa protein band was separated and observed by SDS-PAGE. Conclusion: The protein band of sheep sarcocystis which can be used as antigen in serological methods was parified and detected.

Interleukin (IL) 24 is a pro-inflammatory and tumor suppressor cytokine capable of inducing selective apoptosis in various cancer cells. BR2, on the other hand, is an anti-microbial peptide with selective penetrability to the cancer cells. In this study, we aimed to produce and purify a fusion protein containing IL24 as the toxic moiety fused to BR2, as targeting moiety, and then to evaluate its cytotoxic activities. For this purpose, the coding sequence of IL24-BR2 fusion protein and IL24 were cloned into the pET28a vector and used to transform E. coli BL21 (DE3) cells. Following induction of expression, protein purification performed using Ni-NTA chromatography. SDS-PAGE and western blotting were performed to confirm the expression and purification. Finally, cytotoxic effects of the purified proteins were evaluated on MCF-7 and HUVEC cell lines. Analysis of crude lysate of induced recombinant E. coli BL21 (DE3) bacteria and also purified proteins showed a band of approximately 22 and 18 KDa on SDS-PAGE and western blotting for IL24-BR2 and IL24, respectively. Finally, statistical analysis showed significant cytotoxic effects of IL24-BR2 on MCF-7 cells at 10, 20, and 40 μ g/mL concentrations compared to IL24 alone, which showed no significant cytotoxic effects on cancer cells except in the highest concentration. In conclusion, production and purification of IL24-BR2 fusion protein with potential specific toxicity toward cancer cells was successfully achieved. However, further investigation of the cytotoxic effects of this fusion protein on other cell lines and in vivo cancer models must be performed.

Antiviral proteins (AVP), present in silkworm fecal matter, show activity against nuclear polyhedrosis virus (NPV) in vitro and in vivo. The extract of silkworm fecal matter prepared in phosphate buffer solution of pH 7.5 was subjected to 50% solid ammonium sulfate precipitation to enrich AVP, then which was dialyzed. The dialysate was applied to the column containing silica gel-G, the column elutes were purified by gelfiltration chromatography. The gelfiltration pattern gave three protein peaks A, B and C. The protein obtained from peak fractions of peak A is found to be active against NPV in vitro. Whereas the proteins were obtained from peak fractions of peaks C and B were not shown activity against NPV in vitro. The peak A fractions were collected and further purified by High Pressure Liquid Chromatography (HPLC) using C4 column. Purified AVP of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) resulted in two protein bands with the molecular mass of 23 KD and 16 KD. Thymol sulphuric acid method of carbohydrate staining indicated that both of these protein bands are glycoproteins. AVP activity is determined in vitro by precipitation reaction. In vivo activity of the AVP is confirmed by conducting the bioassay in silkworms.

Recombinant protein purification is a kind of sensitive and expensive method in genetics engineering. Genetic manipulation leads to the expression of various proteins; it should be isolated with high purity finally. Differed methods for protein purification are categorized, based on cast, quality, Easy work and side effect of protein. In this article, we are investigating his His-tag protein purification by magnetic nanoparticles.NiFe2O4 nanoparticles were synthesized by Co-precipitation method, than was dissolved in 0.05 NaCl solutions. Tube containing of nanoparticles and buffer was located in magnetic field. Nanoparticles were separation by the three-stage washed. According to the protocols, nanoparticles located in his-tag protein and the end protein were predicated, and analyzed by the Electrophoreses.The results of gel showed can be extracted that the proteins form a weak that the results of gel showed that proteins isolated are poor by this method. By supplementary study, we get new age or tree-age nanoparticles, that Ni is the surface of N.P. This age of nanoparticles is fit to protein purification.Nano-particle synthesis in this article, are created a two-dimensional grid of nickel and iron oxide nanoparticles that this structure is not suitable for purification of His-tag protein. So the magnetic nanoparticles have a three-dimensional structure of the nickel nanoparticles on the surface of the exposed histidine to be enough space to connect and link. It is hoped in future studies with these types of nanoparticles synthesis to achieved His-protein isolation kit.

Homeobox genes encode transcription factors which play important roles in the developmental processes of many multicellular organisms. TGIFLX/Y (TGIFLX and TGIFLY) are members of the homeobox superfamily of genes. Their expressions are specifically detected in the human adult testis but their functions are remained to be investigated. In this investigation we cloned full length of TGIFLY cDNA and produced recombinant GST-TGIFLY protein in bacterial system. Here we present production of GST-TGIFLY fusion protein as a soluble protein. The recombinant protein was confirmed by western blot analysis using anti-GST antibody. Through a single purification procedure using MagneGST Beads, approximately 20 mg of the recombinant protein was obtained per liter of bacterial culture. We suggest that GST-TGIFLY fusion protein could be utilized as a valuable molecular tool on investigation of TGIFLY target genes and identification of co-factors or partner proteins involved in TGIFLY function in normal and abnormal development.