Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 13Citation - Scopus: 13Macromolecular Changes in Nilotinib Resistant K562 Cells; an in Vitro Study by Fourier Transform Infrared Spectroscopy(SAGE Publications Inc., 2012) Ceylan, Çağatay; Camgöz, Aylin; Baran, YusufNilotinib is a second generation tyrosine kinase inhibitor which is used in both first and second line treatment of chronic myeloid leukemia (CML). In the present work, the effects of nilotinib resistance on K562 cells were investigated at the molecular level using Fourier transform infrared (FT-IR) spectroscopy. Human K562 CML cells were exposed to step-wise increasing concentrations of nilotinib, and sub-clones of K562 cells resistant to 50 nM nilotinib were generated and referred to as K562/NIL-50 cells. Antiproliferative effects of nilotinib were determined by XTT cell proliferation assay. Changes in macromolecules in parental and resistant cells were studied by FT-IR spectroscopy. Nilotinib resistance caused significant changes which indicated increases in the level of glycogen and membrane/lipid order. The amount of unsaturated lipids increased in the nilotinib resistant cells indicating lipid peroxidation. The total amount of lipids did not change significantly but the relative proportion of cholesterol and triglycerides altered considerably. Moreover, the transcriptional status decreased but metabolic turn-over increased as revealed by the FT-IR spectra. In addition, changes in the proteome and structural changes in both proteins and the nucleus were observed in the K562/NIL-50 cells. Protein secondary structural analyses revealed that alpha helix structure and random coil structure decreased, however, anti-parallel beta sheet structure, beta sheet structure and turns structure increased. These results indicate that the FT-IR technique provides a method for analyzing drug resistance related structural changes in leukemia and other cancer types.Article Citation - WoS: 6Citation - Scopus: 8Segment 10 Based Molecular Epidemiology of Bluetongue Virus (btv) Isolates From Turkey: 1999-2001(Elsevier Ltd., 2009) Özkul, Aykut; Ertürk, Arife; Çalışkan, Elvin; Saraç, Fahriye; Ceylan, Çağatay; Mertens, Peter; Kabaklı, Özden; Dinçer, Ender; Çizmeci, Şirin G.Bluetongue is a significant arbovirus infection that has a negative impact on ruminant productivity in Turkey. Twenty-one Turkish BTV isolates were analyzed phylogenetically, based on genome segment 10 (Seg-10) nucleotide sequences. These analyses were used to explore the epidemiological background of individual isolates from both a regional and global perspective. In the regional analysis, the different BTV strains fell into two groups (Group 1 and Group 2). The Turkish virus isolates were localized in Group 1 which contains two sub-groups. The neighbor-joining analysis revealed that Seg-10 of majority of the Turkish viruses was closely related to certain other virus strains allocated in the eastern lineage. The Seg-10's of two viruses (TR25 and TR26) were more closely related to strains isolated in the Asia-Australia region. These strains belong to the 'eastern' topotype identified by [Maan, S., Maan, N.S., Ross-Smith, N., Batten, C.A., Shaw, A.E., Anthony, S.J., Samuel, A.R., Darpel, K.E., Veronesi, E., Oura, C.A.L., Singh,K.P., Nomikou, K., Potgieter, A.C., Attoui, H., van Rooij, E., van Rijn, P., De Clercq, K., Vandenbussche, F., Zientara, S., Bréard, E., Sailleau, C., Beer, M., Hoffman, B., Mellor, P.S., Mertens, P.P.C., 2008. Sequence analysis of bluetongue virus serotype 8 from the Netherlands 2006 and comparison to other European strains. Virology 377, 308-318]. Comparisons of amino acid sequences deduced from the Seg-10 genes showed a high level of conservation in the NS3/3A proteins from the Turkish viruses. The more frequent amino acid substitutions were identified by multiple alignment analysis, and one of the isolates (TR23) was remarkably found to be genetically quite distinct from the other isolates.Article Citation - WoS: 8Citation - Scopus: 10Ruscogenin Interacts With Dppc and Dppg Model Membranes and Increases the Membrane Fluidity: Ftir and Dsc Studies(Elsevier, 2023) Şahin, İpek; Ceylan, Çağatay; Bayraktar, OğuzRuscogenin, a kind of steroid saponin, has been shown to have significant anti-oxidant, anti-inflammatory, and anti-thrombotic characteristics. Furthermore, it has the potential to be employed as a medicinal medication to treat a variety of acute and chronic disorders. The interaction of a drug molecule with cell membranes can help to elucidate its system-wide protective and therapeutic effects, and it's also important for its pharmacological activity. The molecular mechanism by which ruscogenin affects membrane architecture is still a mystery. Ruscogenin's interaction with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) and anionic dipalmitoyl phosphatidylglycerol (DPPG) multilamellar vesicles (MLVs) was studied utilizing two non-invasive approaches, including: Fourier Transform Infrared (FTIR) spectroscopy and Differential Scanning Calorimetry. Ruscogenin caused considerable alterations in the phase transition profile, order, dynamics and hydration state of head groups and glycerol backbone of DPPC and DPPG MLVs at all concentrations. The DSC results indicated that the presence of ruscogenin decreased the main phase transition temperature (Tm) and enthalpy (ΔH) values of both membranes and increased half height width of the main transition (ΔT1/2). The FTIR results demonstrated that all concentrations (1, 3, 6, 9, 15, 24 and 30 mol percent) of ruscogenin disordered the DPPC MLVs both in the gel and liquid crystalline phases while it increased the order of DPPG MLVs in the liquid crystalline phase. Moreover, ruscogenin caused an increase in the dynamics of DPPC and DPPG MLVs in both phases. Additionally, it enhanced the hydration of the head groups of lipids and the surrounding water molecules implying ruscogenin to interact strongly with both zwitterionic and charged model membranes.