فهرست مطالب

Trends in Peptide and Protein Sciences
Volume:1 Issue: 1, Oct 2016

  • تاریخ انتشار: 1395/11/25
  • تعداد عناوین: 6
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  • Mehdi Mogharabi, Mohammad Ali Faramarzi Pages 1-6
    Various proteins and enzymes produced during algal photosynthesis can be used in economic development and environment management, such as in wastewater treatment, production of fine chemicals, and biodiesel production. This mini-review presents various enzymes isolated from algae and suggests that algae, given their unique properties, could be explored for large-scale production of enzymes as future biocatalyst factories.
    Keywords: Algae, Cyanobacteria, Isolated enzymes, Biocatalyst, Biosynthesis
  • Ramin Mazaheri Nezhad Fard Pages 7-13
    First discovered in the 19th century, bacteriophages (phages) are bacterial viruses and the most widespread entities on earth. Phages have multiple important roles in maintaining the bacterial population, carbon cycling, bacterial pathogenicity, and bacterial evolution. They can be used to develop DNA and protein vaccines, novel antibiotics and antiviral drugs, and phage therapy. The International Committee on Taxonomy of Viruses categorizes phages in two major orders of Caudovirales and Ligamenvirales, including five families, nine subfamilies, 145 genera, and 684 species. The most widespread families in nature are Siphoviridae, Myoviridae, Podoviridae, and Inoviridae. Phages are morphologically categorized in two major categories of tailed and polyhedral, filamentous, or pleomorphic phages. They can have either a single- or double-strand DNA or RNA genome. Phages are important for transferring mobile genetic elements, such as virulence genes and antimicrobial resistance determinants to bacteria by transduction, and have been used to treat bacterial infections. In conclusion, phages are important entities because of their roles in bacterial metabolism and surveillance in nature. Further studies can help usobtain a better understanding of the phage mechanism in bacterial evolution.
    Keywords: Bacteriophages, Bacteria, Transduction, Lysogeny, Lysis
  • Nasrin Mohajeri, Zarrin Sharifnia, Mojgan Bandehpour, Fatemeh Yarian, Amaneh Koochaki, Nariman Mosaffa, Kazem Parivar, Bahram Kazemi Pages 14-19
    Silencing of gene expression by siRNA (small interfering RNA) is a powerful approach used to study the genetic analysis and functional roles of mammalian genes. There is at present no report about the effects of mammalian two-hybrid system plasmids delivery of sense and antisense strands. The leishmania pteridine reductase 1 (PTR1) gene was cloned as sense and antisense strands into mammalian two hybrid system plasmids. The constructs were transfected into human blood macrophages on the basis of eight experimental groups. (Antisense strand ± LPS, sense strand ± LPS, dsRNA ± LPS, negative control ± LPS). After 24 hours, cytokines production was assessed with ELISA.
    Transfection of sense and antisense strand RNA into monocyte-derived macrophages (MDM) was confirmed by RT-PCR. Single strands RNA expressed IL-8, IL-12, IL-1β inflammatory cytokines and dsRNA induced IL-8, IL-12 and TNF-α production in MDM. In contrast, random uptake from a mixture of two plasmids was downregulated IL-8, IL-12, IFN-γ cytokines, with a significant difference of p
    Keywords: sense, antisense, dsRNA, gene expression, monocyte, macrophage
  • Zeinab Sharafi, Javad Ranjbari, Jaber Javidi, Nastaran Nafissi-Varcheh, Maryam Tabarzad Pages 20-26
    Protein-coated nanoparticles have diverse applications in biomedical science. The protein hydrophobic domains or surface electrostatic charge conducts adsorption of proteins to different surfaces. This property can be customized to immobilize specific molecules on solid supports for experimental screenings or purification processes. To develop highly selective affinity ligands—such as aptamers—against specific protein targets, protein coated magnetic particles have been successfully applied. This approach could be highly efficient in affinity ligand development against coagulation factor VIII.In this study, magnetic nanoparticles were prepared by co-precipitation method and, then, a gold coating was run on the MNPs’ surface. The gold coating could add some attractive specifications to the protein immobilized nanoparticles during the aptamer selection process, such as simultaneous affinity determination of aptameric oligonucleotides by fluorescence-based methods. The gold surface has been indicated as a specific feature for covalent binding to the sulphur functional groups of various molecules. In proteins, sulphur units of cysteine or methionine might be bound covalently to the gold surface. In addition, nonspecific and non-covalent attachment of proteins to the gold particles may be performed. Therefore, a series of samples containing different mass ratios of protein to gold magnetic nanoparticles (GMNPs) were evaluated to find the best conditions for coagulation factor VIII immobilization. The results showed that the best condition for high coating efficiency was 48 h incubation at 4 ºC of protein and GMNPs with a mass ratio of 0.5% in PBS 25mM, with pH=7 as binding buffer.
    Keywords: Gold magnetic nanoparticles, Human coagulation factor VIII, Protein immobilization, Surface coating
  • Milad Taherian, Hajar Yaghoobi, Mojgan Bandehpour Pages 27-30
    The venom of the viper is very important in pharmaceutical usage, such as in the process of coagulation during medical care. This study aims to evaluate the coagulant factor of Latifi and Zanjani viper venom. In the current study, after electrophoresis of proteins found in viper venom, all of the thick and strong bands of proteins were isolated and prepared for examination of coagulation characteristics, like pro-thrombin time (PTT) and active partial thromboplastic time (APTT), followed by further study by mass spectroscopy. In this way, 11 bands of proteins were recognized in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). After PT and APTT tests, one common band in 26 KDa could lead to coagulation of blood plasma in less than one second. Mass spectroscopy identified this band as serine protease isoform4. The results confirmed the coagulation effect of a 26 KDa protein fraction of venom from Latifi and Zanjani vipers.
    Keywords: Latifi viper, Zanjani viper, SDS PAGE, PTT, APTT
  • Mehrdad Pazhouhandeh, Faranak Salmannejad, Nastaran Nafissi-Varcheh, Maryam Tabarzad Pages 31-37
    Aggregation is one of the main physical instabilities of proteins, which might occur during all steps of the manufacturing and storage of products. The presence of protein aggregates may result in the reduction of activity, induce immunologic responses and failure of therapeutic efficiency. Therefore, using additives in drug formulations is one of the essential approaches to prevent protein aggregation. The main objective of this study was to evaluate the inhibitory influence of arginine or glycine as excipients on the aggregation behavior of recombinant human growth hormone (rhGH). Two types of mechanical and thermal stresses including freeze-thaw and vortex-agitation were applied to the 1 mg/mL protein solution in PBS buffer (25 mM, pH = 7) in the presence and absence of arginine and glycine. The influence of arginine or glycine at the concentration of 320 mM on reduction of rhGH thermal/mechanical-induced aggregation was evaluated using SE-HPLC and turbidity measurement. The results of this study revealed that the monomer concentration decreased linearly; and therefore, aggregate formation was intensified with the increase in the number of freeze-thaw cycles. Moreover, it was found that a significant amount of rhGH (> 80%) was rapidly adsorbed at the walls of the vessels or converted to insoluble aggregates. Arginine decreased the insoluble aggregate formed during the freeze-thaw cycling more effectively than glycine. In addition, following the vortex-agitation stress, arginine had the optimum preventive effect in aggregate formation in contrast to glycine, which increased the formation of insoluble aggregates. The findings revealed that arginine may be a potential additive in preserving rhGH against thermal/mechanical-induced aggregation.
    Keywords: Aggregation, Arginine, Glycine, Protein stability, Recombinant human growth hormone