نشریه زیست فناوری دانشگاه تربیت مدرس
سال چهارم شماره 2 (پیاپی 6، پاییز و زمستان 1392)

Sheath blight، caused by Rhizoctonia solani AG1-IA، is one of the most destructive disease. Conventional methods of disease control using fungicides may develop new problems. Therefore، understanding molecular mechanisms of plant–pathogen interaction is necessary to adopt effective approaches for managing the disease. Here for the first time، by using bioinformatics tools and RT-PCR analysis and sequencing confirmed the presence of a Magnaporthe oryzae Avr-pita gene orthologous sequence designated as Rhiz-pita1 gene in three different geographic isolates of R. solani AG1- IA (A2،R1 and T2) genome. SignalP program predicted a secretion signal upstream of Rhiz-pita1 gene. Nucleotide sequences of 5'' region of Rhiz-pita1 gene from geographical isolates showed 99% identity in exons and 100% in introns which are characteristics of fast evolving effector proteins. Also، 98% homology between Rhiz-pita and M. oryza-pita1gene suggests that Rhiz-pita encodes an effector protein. Howevere، more researchs are necessary to confirm of this suggestion.

With the instrumentation of Mass Spectrometry (MS) and advances carried out in bioinformatic tools and databases، along with birth of nanotechnology in 1990s، biology experienced a dramatic revolution and new perspectives were found in molecular biology and medicine، agriculture، environmental sciences and pharmatiuticals. The most important one is systematic look at the entire organism and solving biological problems at the level of entire system viewed as an integrated and interacting network of genes، proteins and biochemical reactions (Systems Biology). In addition، union of biology and nanotechnology result in creation of nanobiotechnology. This paper provides an easy-to-read guide to the concepts of some of the major topics in today’s biology. Topics discussed here، include fundamentals of proteomics and systematic descriptions of the various types of studies in proteomics. After a brief review on the physical principles of nanotechnology، the application of one of its products، known as quantum dot in biology and particularly، proteomics studies، were discussed. This account covers the general principles and applications of new emerging fields in biology.

In the last decades، increasing petroleum prices، diminishing oil resources، incessant fluctuations in the oil prices and concerns about global shortage of energy resources have boosted research on production and commercialization of biofuels، e. g.، ethanol and butanol، obtained from renewable resources. Besides its application as a fuel، butanol has found numerous industrial applications for the production of plasticizers، lacquers، coatings، detergents، and brake fluids. Biobutanol، together with acetone and ethanol، can be produced in industrial scale by a process called Acetone Butanol Ethanol (ABE) fermentation in anaerobic condition using Clostridium acetobutylicum bacterium. The nature of the carbohydrate and nutrients in the fermentation can affect the ratio of solvents obtained in the ABE fermentation process. In this research، influence of various nutrients and glucose concentrations on the production of butanol by this bacterium was investigated. Results showed that presence of biotin، thiamine، para-amino-benzoic acid، and yeast extract as well as several ions including Mg، Fe، Mn، phosphate، and ammonium acetate in the culture medium is essential for the production of butanol by C. acetobutylicum. Lacks of these compounds in the medium significantly reduced the production of solvents، in spite of the growth of the bacterium. also optimum concentration of glucose was 40g/l for maximum production solvent. In this concentration، maximum solvent concentration was achieved 10. 5 g/l and maximum butanol concentration was achieved 6. 7g/l with yield of 26. 25%.

ATP sulfurylase (ATPS) is widely distributed in all living organisms. Several different physiological roles have been proposed for ATPS in different species، including sulfate assimilation، sulfate reduction and pyrophosphate recycling. Also، ATP sulfurylase has many different industrial and laboratory applications. The aim of this study was to clone and express the gene that producing the recombinant ATPS protein from an Iranian strain of Geobacillus. After Isolation and identification of Geobacillus kaustophilus strain، DNA genomic was extracted. ATPS gene was amplified from genomic DNA by using a couple of specific primers for interested gene. PCR product of ATPS gene was observed as an 1188bp band on agarose gel. Then the PCR product was purified and cloned into the cloning vector. The ATPS band was sequenced after cloning and result of homology search in the NCBI database confirmed that the cloned gene was ATPS. The ATPS gene was subcloned in expression pET28a plasmid. Expression of recombinant ATPS protein in E. Coli BL21 (DE3) was analyzed using SDS-PAGE gel. Analysis of expressed ATPS protein on SDS-PAGE gel revealed a band at 47. 5 KD. Using ATP luminescence method for measuring enzymatic activity of the protein showed that the recombinant protein is active. This is the first study on cloning، expression and enzymatic activity of the ATPS gene from the Geobacillus kaustophilus bacteria.

Nowadays، biological substances have allocated many applications to themselves in distinct industries. In this field، biological molecules with various potentials have been identified، from which we can refer to bacteriorhodopsin (BR). Bacteriorhodopsin is found in purple membrane of halobacterium salinarum. Due to its stability and various characteristics like possession of properties of a proton pump، bacteriorhodopsin has many applications in different industries. One of the most important industrial and semi-industrial production processes for bacteriorhodopsin is the isolation and purification of the purple membrane. In this investigation، after halobacterium salinarum culture، the purification was done according to the Yucel method. So as to produce bacteriorhodopsin in semi-industrial scale، a modified method was developed by substitution of mechanical approach with enzymatically method to destruction of DNA and uses of osmotic shock instead of dialyze. This method led to decrease of time and isolation cost in comparison to Yucel method. The contamination percentage of the PM was estimated below 5% for both methods. The purification percentages were 67±1% and 68±4% for the modified method and Yucel method، respectively، which is indicating of the equal purification percentage for both methods. Bacteriorhodopsin amount was 8. 2±0. 4، 8. 1±0. 6 mg per liter for the improved method and Yucel method، respectively. The enzyme activity assay by Kuyama method indicated that the pH variation was 1 unit with the same BR amount for both methods. Hence، the modified method introduced in this investigation could reduce time and costs of the purification by maintaining the BR characteristics.

One of the most promising strategies in cancer therapy is to induce apoptotic pathway. For this purpose، several constructed agonists of Death Receptor 5 (DR5) are in clinical development. Extrinsic and intrinsic apoptosis pathways of various cancer cells are primarily induced through the activation of the proapoptotic DR5. The extracellular domain of DR5 is comprised of several functional domains، among them the cysteine-rich domains (CRDs) play a critical role in TRAIL-DR5-mediated apoptosis. It has recently been shown that the binding of agonistic monoclonal antibody to another N-terminal domain of DR5 could mediate its activation and apoptosis induction. Variable domains derived from heavy chain antibodies (hcAb) called VHHs or nanobodies are robust، efficient and smallest antigen binding fragments. These unique features of VHHs make them potential therapeutic and diagnostic candidates. In the present study، using phage display technology، a library containing VHH genes was generated of an immunized camel with hapten-peptide 1ITQQDLAPQQRA12 and used to isolate the binders of this peptide. Through screening the phage library، three binders with high binding ability to desired epitope in the NTR region were obtained. Considering to the key role of this epitope in apoptosis inducing، these selected binders could be potential candidates to trigger apoptosis in various cancer cells.

Biodegradable polymeric nanoparticles are highly regarded in drug delivery due to bioavailability، better encapsulation، controlled release and low toxicity. Drug encapsulation in polymeric nanoparticles may improve the therapeutic effects of these compounds. Polymers are divided in two types: natural and synthetic. Chitosan، as a natural polymer، can have many applications in drug delivery due to good properies. The purpose of this study is to optimization of the production of chitosan nanoparticles for drug delivery. Chitosan nanoparticles were prepared according to ionic gelation method and characterized. Prepared nanoparticle morphology investigated using SEM and particle size distribution، and surface charge and polydispersity index (PDI) were determined by Nanozeta Sizer. FTIR spectra of the lyophilized samples were recorded and proved the formation of nanoparticles. This study has shown that the particle size and zeta potential can be controlled by a change in the ratio of the weight and volume of chitosan and pH adjustment.