condition are essential for their life. Thermophils have special enzymes and metabolic characteristics that are used in biotechnology. Since thermophiles live in stressful environments it will be very useful to study their survival mechanisms. Materials and methods: The bacteria growing at 75 °C were trans- ferred to 45 °C water bath when the optical density (OD ~620 nm) reached 0.6, then the total proteins extracted from the cell lyses. Individual protein spots were excised from the 2-D gels then subjected to in-gel digestion and analyzed by tandem MALDI-TOF MS by using of SwissProt and NCBI database and MASCOT software. Results: In this condition bacteria change their metabolic strategies and begin to synthesize different proteins and other necessary molecules. Within the first 8 h after cold shock at 45 °C the bacterium growth rate and total protein concentration increased. Conclusion: Up-regulated antioxidant proteins and the proteins involved in detoxification showed the creation of oxidative condition about 8 h after cold shock on thermophilic bacterium. It is possible to extract and use these stable proteins as diagnostic indicators or protein markers in physiological condition. Keywords: Cold shock, Oxidation, Thermophil doi:10.1016/j.clinbiochem.2011.08.1031 Oral – [A-10-510-1] The effect of Zn 2+ on exposure of hydrophobic patches of carbonic anhydrase Sima Afsharnezhad a , Shadi Nasr Esfehani a , Shabnam Nasr Esfehani a , Saman HosseinKhani b , Majjid Monajjemi c a Department of Biochemistry, Medical Sciences, Mashhad Islamic Azad University, Mashhad, Iran b Department of Biochemistry, Faculty of Basic Science, Tarbiat Modares University, Tehran, Iran c Department of Physical Chemistry, Science & Research Branch, Islamic Azad University, Tehran Iran E-mail address: sanegad@yahoo.com (S. Afsharnezhad) Introduction: The enzyme hydrophobic patches are the newly formed regions that gain the capacity to interact with the hydrophobic supports. Zinc can induce hydrophobic exposure and/or aggregation of many proteins. Materials and methods: Our previous studies indicated that carbonic anhydrase is not normally immobilized on hydrophobic support and it acquires this ability upon denaturation. In the present study, an apo form of the carbonic asnhydrase was prepared by removal of zinc and a comparative study was performed on hydrophobic exposure character- istic features of the apo and native forms by 1-anilino naphthalene-8- sulfonate (ANS) binding and molecular dynamic simulation. Result: Results indicate that the relatively small increase in ANS fluorescence in apo form and the theoretical model estimate the hydro- phobic sites become more exposed in relation to the zinc position in native form. Accordingly, most of exposed residues to solvent in apo form are non-polar and are placed in a-helix structures. In contrast, for native carbonic anhydrase, the most residues that are exposed to solvent are located near to zinc position and are placed in b-strands and non- accessible. Conclusion: Data presented here may provide useful information in connection with carbonic anhydrase immobilization on hydrophobic adsorbents. Keywords: Zinc, Apo-carbonic anhydras, Hydrophobic exposure doi:10.1016/j.clinbiochem.2011.08.1032 Poster – [A-10-627-1] Critical and synergy nodes in insulin-EGF signaling network Mohammad Reza Housaindokht a , Hassan Monhemi b , Mohammad Reza Bozorgmehr c , Ahmad Reza Bahrami a a Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran b Biophysical Chemistry Laboratory, Department of Chemistry, Faculty of Science, Ferdowsi University, Mashhad, Iran c Department of Chemistry, Faculty of Science, Islamic Azad University, Mashhad Branch, Mashhad, Iran E-mail address: h_monhemi_chem@ymail.com (H. Monhemi) Introduction: Signaling pathways are not isolated from their surroundings. They are also intervened by other signaling pathways; known as “crosstalk mechanism”. One of the most important crosstalk mechanisms is the insulin-EGF networks. In this study, we used the analytical tools of the systems biology workbench for elucidating of some ambiguities of the insulin-EGF crosstalk. Materials and methods: The construction and further analysis of the model was carried out by Matlab simbiology toolbox. This toolbox can perform time-dependent sensitivity analysis. Results: Based on sensitivity analysis, we reconstructed an elucidated model with 51 chemical reactions in comparison with the previous model with 111 chemical reactions. We noticed two controlling pathways with direct participation of phosphorylated insulin and EGF receptors that involve insulin receptor substrate (IRS) and Src kinase modules. Also, insulin pathway by producing phosphatidylinositol-3, 4, 5-triphosphate (PIP3), and EGF pathway by activation of GAB1, control the downstream events and lead to potentialities in the mitogenic signal. Surprisingly, Shc and phosphatase SHP2-dependent reactions have no significant roles in the synergy conditions and are not involved in the reduced model. Conclusion: The main aims of current study are to reproduce an elucidated model of insulin-EGF networks and reliably determine the controlling and synergy nods of this crosstalk. Interestingly this reduced model (with 51 chemical reactions) reproduces the results of the original model (with 111 chemical reactions) in synergy conditions. Keywords: Signaling pathways, Crosstalk, Computational modeling, Systems biology, Insulin-EGF networks, Sensitivity analysis doi:10.1016/j.clinbiochem.2011.08.1033 Oral – [A-10-798-1] 3-Dimentional molecular modeling studies of KSHV vOX2 protein as an example of highly glycosylated and adhesive molecule Hamid Sadeghian, Abbas Ali Amini, Houshang Rafatpanah, S.A. Rahim Rezaee Immunology, Medical School, Mashhad University of Medical Sciences, Mashhad, Iran E-mail address: abbasali_amini@yahoo.com (A.A. Amini) Introduction: KSHV which is the etiological agent of Kaposi's Sarcoma encodes a protein by open reading frame (ORF) K14, called vOX2. This protein shares identity with the mammalian OX2 (CD200). Signal delivery of vOX2 occurs through binding to CD200R which contributes to maintaining the homeostasis of immune responses, in a manner similar to CTLA-4 and PDL-1/-2. Due to highly glycosylation and adhesive properties of vOX2, it failed to determine the 3D-structure of the protein by X-ray crystallography method. Therefore, probable crystal structure of vOX2 has been bioinformatically identified. Material and methods: In order to identify the templates, BLAST sequence homology searches (NCBI) were performed. The PD-L1 (PDB Abstracts S33