Background: Streptokinase (SK) is most widely used for treatment of myocardial infarction, however, it is the most expensive thrombolytic agent. A major drawback to SK use is the widespread presence of anti–streptokinase antibodies (Abs). These Abs cause allergic reactions and neutralize streptokinase therapeutic effects.Materials and methods: To produce an engineered variant of streptokinase being functional and less antigenic than the native molecule, we cloned and expressed streptokinase mutant gene lacking the C-terminal 42 amino acids. Recombinant protein was confirmed by western blot analysis with anti T7 monoclonal antibodies.Results: pGEMEX-1 expression vector contains T7 gene 10 protein as fusion protein immediately downstream of T7 promoter and before multiple cloning site, streptokinase mutant gene was cloned after fusion protein.Conclusion: We cloned and expressed mutant streptokinase gene, lacking the C-terminal 42 amino acids. If mut-C42 activity was less affected by neutralizing antibodies compared with native streptokinase, this engineered variant could be a preferred alternative to native streptokinase for thrombolytic therapy.

Background: Ferritin has an important role in iron storage in the cells, and due to its nanocage structure and self-assembly properties, it has wide application prospects in nanobiotechnology. Methods: The maize (Zea mays) ferritin gene ZmFer1 was cloned and expressed in Escherichia coli BL21 (DE3) for the first time. Change in macromolecular structure of ZmFer1 ferritin due to heat treatment was investigated using native PAGE electrophoresis, DLS, and TEM. Change in the secondary structures of the protein was evaluated using CD spectroscopy. Moreover, alteration in the conformation of the protein was evaluated using UV-absorption spectra and intrinsic fluorescence spectra. The Tm of ZmFer1 was obtained using DSC. Finally, the effect of heat on the function of ZmFer1 was assessed by iron loading ability. Results: The purified ZmFer1 protein showed a homopolymer nanocage structure. The results of native PAGE electrophoresis, DLS, and TEM techniques showed that ZmFer1 protein nanocage is stable to heat treatment up to 90 °, C, and some of the protein nanocages retain their macromolecular structures even at 100 °, C in liquid aqueous solution. Based on the DSC results, ZmFer1 protein nanocage had a Tm of 81. 9 °, C. After treatment at 100 °, C, stable ZmFer1 protein nanocages were able to store iron atoms. Conclusion: Recombinant ZmFer1 ferritin with a Tm > 80°, C is a hyperthermostable protein nanocage. The results of this study are beneficial for the development of protein nanocages that are stable under extreme temperature conditions, as well as application of ZmFer1 in nanobiotechnology, biomaterials, and biomedical fields.

Introduction: Production of antibodies against specific proteins of testis germ cells is of great significance for the investigation of processes involved in spermatogenesis, study of infertility problems and determination of the probable role of these proteins as cancer-testis antigens. Murine Testis Specific Recombinant protein 101 (mTEX101) is a 38kDa, GPI-anchored protein which is expressed in testis germ cells of adult mice but it seems to be absent in other tissues. The structure and function of mTEX101 is not completely understood yet, but it is speculated that it may transducer biochemical signals into the cytoplasm since mTEX101 does not have an intracellular domain but the precise mechanisms are still ambiguous.Materials and Methods: RNA was extracted from three adult mice testis. The RNA was used in RT-PCR, employing a pair of specific primers for mTEX101 ORF region. TA-cloning technique was performed by the insertion of mTEX101 into a pGEM-T Easy Vector, followed by its sub cloning into a His-tagged expression vector, pET-28a (+). The Recombinant mTEX101 was then produced by transfection of the expression vector into BL 21 (DE3) E. coli strain. Results: A Recombinant protein, weighing 27kDa, was produced upon IPT Ginduction of the bacterial host. The presence of mTEX101 protein was detected through Western blot analysis by anti-mTEX101 peptide antibodies. Conclusion: We produced mTEX101 Recombinant protein that could be used for the production of mono and polyclonal antibodies.

Objective: With considering about our extended information in genome sequence field which gathered in genome data banks nowadays discovering the genes function and their products still unclear that’s why study in this area sensed. Proteomics researches are one of the powerful tools for reach to this knowledge.Materials and Methods: In our study at first we prepare competent cells from Escherichia coli species named BL21 for expressing Recombinant protein, then in several stages, essential condition for processing Recombinant protein, of this sort; change in culture temperature, induction time and concentration of IPTG for protein expression, time and number of sonication pulses for breaks in bacterial membrane and releasing cytosolic contents,at least change in kind and concentration of detergents for eliminate membrane debris were adjusted. All of the results step by step classified and optimized.Results: The optimized concentration of IPTG was 0.1 mM. There was not any significant difference between the used detergents as both of them had the same effect on permeabilization of the bacterial membranes. Finally we detected the Recombinant GST-PEP by SDS page analysis with both of Commasie Brilliant Blue staining (CBB) and western blot using anti GST antibody.Conclusion: Taken together these data showed that PEP (peroxisomal protein)which containing fibronectin type III and two hydrophobic domains should be assessed by further proteomics analysis to discover it's interactions with other proteins in neural stem differentiated cells.

Introduction: COVID-19 pandemic caused by the emerging SARS-CoV-2, being the cause of COVID-19, leads to acute respiratory syndrome and is a vital threat to global health and the economy since it was identified in late December 2019 in China. Due to the limitations and long-time of vaccine production, most countries were forced to design and produce antigens, kits, and anti-viral drugs so that they might be able to prevent deaths caused by COVID-19. This study was conducted to design and express S1 protein of SARS-CoV-2 to be used as a vaccine candidate. Methods: Recombinant pPICZαA plasmid was replicated in Escherichia coli and the linearized plasmid was transfected into Pichia pastoris yeast as an endosomal fragment. After screening the colonies with Zeocin and confirming the presence of the gene and vector promoter inside the genome extracted from yeast, the expression of S1 protein was induced in BMMY medium with methanol. Results: The S1 protein was successfully expressed in P. pastoris and the results obtained on the SDS-PAGE indicated the presence of a protein with 130 kDa molecular weight, confirmed by Western blotting. Conclusion: The results of the present study showed that the yeast expression system of P. pastoris can be a suitable method to produce glycoprotein S1 as a vaccine candidate or a diagnostic antigen against COVID-19.