Dissertations / Theses on the topic 'Inhibitor'
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Rodkey, Elizabeth A. "INHIBITOR RESISTANCE MECHANISMS AND INHIBITOR DESIGN IN ¿¿-LACTAMASES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1354463033.
Full textShkirskiy, Viacheslav. "Corrosion inhibition of galvanized steel by LDH - inhibitor hybrids : Mechanisms of Inhibitor Release and Corrosion Reactions." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066216/document.
Full textThe current work was dedicated to the investigation of the fundamental mechanisms of the action of a layered double hydroxide (LDH) inhibitor hybrid coated systems for the corrosion protection of galvanized steel. The objective of the work was achieved by the realization of three milestones: (1) the identification of the effective water soluble inhibitor on Zn and steel substrates and the understanding the mechanisms of its action, (2) the revealing the factors and mechanisms controlling the release of the selected inhibitor from Zn2Al/-LDH hosts and (3) the understanding the mechanisms of coated system controlled by inhibitor release and its action. MoO42- showed the best inhibition efficiency comparable to CrO42- in alkaline and neutral solutions. The protective properties of MoO42- were assigned to the fast formation of Mo(V) film. The effect of MoO42- on the dissolution of low carbon steel was also verified to exclude the possible accelerating effect of chosen species. The leaching tests showed that MoO42- release from LDH was controlled by the nature of the exchanged ions from the media by ion-exchange mechanism at neutral pH and by the dissolution of the LDH framework at alkaline pH. The presence of only Cl- resulted in less than 40 % of MoO42- release after 24 hours of the immersion while the additions of the carbonates resulted in 100 % release after 1 hour. The immersion tests showed slight inhibiting effect of coated system in Cl and high in CO32- medias coherent with higher level of MoO¬42- released. The ways to control the inhibitor release and hence, the inhibition performance of coated systems were discussed in the vein of environment composition
Hirst, Claire Elizabeth 1971. "Tissue distribution and regulation of the granzyme B inhibitor, proteinase inhibitor 9." Monash University, Dept. of Biochemistry and Molecular Biology, 2002. http://arrow.monash.edu.au/hdl/1959.1/8488.
Full textRoweth, Harvey George. "Mechanisms of platelet inhibition by the selective serotonin reuptake inhibitor citalopram." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/275477.
Full textGuzanov, Pavel. "ERAP1 inhibitor development." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:e4369016-ab8f-445d-ab1a-71129b495a37.
Full textClarke, Tyler Brooke. "Studies on the inhibitor selectivity and inhibitory signal transfer of a-Isopropylmalate synthase." Thesis, University of Canterbury. Chemistry, 2013. http://hdl.handle.net/10092/11303.
Full textMenon, V. "Molecular and functional aspects of hydrolyases / inhibitors with emphasis on aspartic protease inhibitor." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2012. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2401.
Full textMiyazaki, Hiroshi. "Studies on Inhibitors of Plasminogen Activator Inhibitor-1(PAI-1) and Inhibitors of PAI-1 Production as Antithrombotic Agents." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/126818.
Full textAhtyamova, Daria. "Cholinesterase inhibitor: pharmacological application." Thesis, Київський національний університет технологій та дизайну, 2019. https://er.knutd.edu.ua/handle/123456789/13033.
Full textMcCready, Tara Lyn. "Inhibition of protein phosphatase-1 by endogenous inhibitor proteins and natural product toxins." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0032/NQ46885.pdf.
Full textChen, Ping. "Inhibitor adsorption study and the effect of inhibitor on kinetics of BaSO4 crystal growth." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/1336.
Full textPoliakov, Anton. "Peptide-Based Inhibitors of Hepatitis C Virus NS3 Serine Protease: Kinetic Aspects and Inhibitor Design." Doctoral thesis, Uppsala universitet, Institutionen för naturvetenskaplig biokemi, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4127.
Full textSchempp, Christina Maria. "The V-ATPase inhibitor archazolid." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-168586.
Full textCao, Xianhua. "Simultaneously targeting hypoxic cancer cells by hsp90 inhibitor and glycolysis inhibitor in pancreatic cancer therapy." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1173117669.
Full textKreienbühl, Peter Lukas. "Protein phosphatase inhibitor okadaic acid alters cell shape and F-action distribution and inhibits /." Bern, 1992. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Full textReid, Anne Marie. "Raf-1 kinase inhibitor protein modulation of the cellular response to chemotherapeutic drugs and PDE5 inhibitors." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2497/.
Full textHaworth, Caroline Joanne. "Cloning and expression of a modified oryzacystatin inhibitor gene and an investigation of its inhibitory capabilities." Doctoral thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/9485.
Full textCysteine proteinase inhibitors have shown potential as biocontrol agents for the protection of plants against insect and pathogen attack. With the advent of protein and genetic engineering such inhibitors can now be modified in order to improve their effectiveness. Because cystatins have already been isolated from plants. they provide a good starting point for developing modifications which may improve their function as biocontrol agents. The purpose of this project, therefore, was to design a potentially improved analogue of the rice cysteine proteinase inhibitor, oryzacystatin I, through molecular modelling studies. The gene sequence for this modified protein was then synthesised and expressed for kinetic analysis and insect trial assays. A prediction of the oryzacystatin I (OC I) tertiary structure was made using Biograf software on an Evans and Sutherland workstation. This structure was based on the known structures of stefin B and chicken cystatin ho se co-ordinates are published in the Brookhaven data files. Chicken cystatin is one of the most potent inhibitors of papain in the cystatin superfamily. This is believed to be due, in part, to an increased binding of the cystatin to papain through its amino-terminal region with the residues Leu7 to Gly9 playing a particularly important role.
Dabos, Maria Laura Belen. "Structural and functional insights into the substrate specificity of OXA-48-like carbapenemases." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS402/document.
Full textAntimicrobial resistance is the most alarming emerging problem in infectious diseases. b-Lactams, due to their safety, reliable killing properties and clinical efficacy, are among the most frequently prescribed antibiotics used to treat bacterial infections. However, their utility is being threatened by the worldwide proliferation of b-lactamases (BLs). BL-mediated resistance does not spare even most powerful b-lactams, carbapenems, whose activity is challenged by carbapenemases. OXA-48, a carbapenem-hydrolyzing class D b-lactamase (CHDL) initially identified from a Klebsiella pneumoniae isolate from Turkey in 2001, has since spread globally with the isolation of more than 30 variants. Most OXA-48-like enzymes hydrolyze penicillins at high level, carbapenems at low level and lack significant expanded-spectrum cephalosporin (3GC) hydrolysis, others such as OXA-163 hydrolyze expanded-spectrum cephalosporins and poorly carbapenems. Comparison of OXA-48 tertiary structure with those of other CHDLs revealed small differences located mainly in the loops connecting secondary structure elements, which may vary in length and orientation. The loop located between the b5 and b6 strands (Tyr211 to Pro217) has been suggested to play a major role in carbapenem hydrolysis.To better understand the contribution of the b5-b6 loop in the carbapenem hydrolysis of OXA-48-like carbapenemases, we investigated, using biochemistry and structural biology, natural OXA-48 variants with changes in different loops, replaced each AA of the loop b5-b6 by alanines, performed increasing deletions or increased the size of this loop by replacing it with that of OXA-18, a clavulanic acid inhibited class D b-lactamase that presents activity against expanded-spectrum cephalosporins and none against carbapenems. The resulting OXA-48loop18 was able to hydrolyze expanded-spectrum cephalosporins and conserved partial carbapenem hydrolysis. Structural analysis demonstrated that the loop swap produced an opening of the active site, being now accessible to b-lactams with bulky sidechains e.g. ceftazidime. Additionally, by performing alanine replacements in the b5-b6 loop we could show reduced hydrolysis of carbapenems, mostly reflected by changes in kcat. By increasing deletions in the b5-b6 loop, starting from Tyr211 to Pro217 and from the Pro217 to Tyr211, the activity against carbapenems decreased with the size of the deletion whereas the activity against ceftazidime increased. 4 AA deletions revealed the highest 3GC activity, except for one single AA mutant, OXA-48∆P217, with high level carbapenem and ceftazidime hydrolysis. Crystallography along with molecular modelling showed an increased flexibility of this loop allowing different sized b-lactams to enter the active site. Moreover, the characterization of three novel natural OXA-48 variants revealed structural features important in the observed hydrolysis profile. Thus, the I215-E216 deletion and R214K substitution in the b5-b6 loop of OXA-517 induced the hydrolysis of carbapenems and C3G at high level. In OXA-519, the V120L substitution is located at the bottom of the binding site, in the close vicinity of the active Ser70 and the b5-b6 loop, and therefore overall higher Km values were observed compared to OXA-48. The bulkier side chain of L120 in OXA-519 hampers the approach of b-lactam substrate, resulting in a decrease of the substrate affinity. Finally, we have characterized the chromosomally-encoded OXA-535 that is more distantly related to OXA-48 (91.5% AA identity), despite similar hydrolysis profiles. Interestingly, OXA-535 presented 98.9% of AA identity with the plasmid-mediated OXA-436 suggesting that the blaOXA-535 gene might be the progenitor of the plasmid-encoded blaOXA-436 gene.Taken together, our work illustrates the propensity of OXA-48 to evolve through mutations to accommodate different substrates in its active site and how the b5–b6 loop determines the specificity of the enzyme
Furnish, Robin. "Evaluating Immune Modulatory Therapeutic Strategies for Diffuse Intrinsic Pontine Glioma." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1595849080346532.
Full textFreeman, Thomas Charles. "Studies of pancreatic secretory trypsin inhibitor." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46304.
Full textAlotaibi, Fahad T. "Plasminogen activator inhibitor-1 in endometriosis." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/59961.
Full textMedicine, Faculty of
Graduate
Izzi, Luisa. "CEACAM1 as a tumor cell inhibitor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ55070.pdf.
Full textHolmes, David Ian Roderick. "Phage display of chymotrypsin inhibitor II." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283414.
Full textGariani, Talal. "Design of serine protease inhibitor peptides." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267244.
Full textBoak, Lorraine Scott. "Factors that impact scale inhibitor mechanisms." Thesis, Heriot-Watt University, 2013. http://hdl.handle.net/10399/2670.
Full textChristofakis, Steven. "SCRIBBLE: A POTENTIAL DUAL KINASE INHIBITOR." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/72.
Full textChee, Lai Yuen. "p53, a novel inhibitor of apoptosis." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/6835.
Full textHe, Hua, and 何華. "Anti-tumor mechanisms of cyclooxygenase inhibitors and a c-Jun-N-terminal kinase inhibitor in gastrointestinal cancers." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B30075245.
Full textRoever, Lisa. "Inhibitor Studies for 5’-ecto-nucleotidase (CD73)." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1553892946798977.
Full textNoma, Naruto. "Inhibition of MMP-2-Mediated Mast Cell Invasion by NF-κB Inhibitor DHMEQ in Mast Cells." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225446.
Full textTuck, Benjamin. "Investigating Multispecies Biofilms on Steel Surfaces in Seawater and Biofilm Inhibition by a Novel, Multifunctional Inhibitor." Thesis, Curtin University, 2022. http://hdl.handle.net/20.500.11937/89066.
Full textGeng, Xinyan. "Investigations into how best to target FGFR2 mutant endometrial cancer." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/123437/1/Xinyan%20Geng%20Thesis.pdf.
Full textNakahira, Marcel. "Caracterização físico-química e estrutural do SbKI, um inibidor de serinoproteases de sementes de barbatimão (Stryphnodendron barbatiman)." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-01042014-174549/.
Full textProteinase inhibitors perform many beneficia1 roles in plants such as defense against the attack of seed predators, regulation of endogenous enzymes and sources of proteins and amino acids. Many inhibitors are used in biochemistry research, as well as human pathology treatment such as inflammation and cancer. In this work, a serino proteinase inhibitor found in Stryphnodendron barbatiman seeds (barbatimão) was purified, characterized and denoted SbKI. Mature barbatimão seeds were ground and suspended in PBS pH 7.4 (15 wlv) and stirred for 14 hours at 4OC. The suspension was centrifuged, filtered and treated with PVPP and denoted EB. This EB inhibited blood coagulation and some serine proteinases activities. The inhibitor SbKI was purified by three chromatography step: molecular exclusion (on Supredex-75, 10/30), ion exchange (on Mono-S, 5/5), both connected to AKTA Purifíer System and reversed phase (on C-18, Waters 250 x 4.6 mm) connected to HPLC System. In each purification step the presence of inhibitor was monitored, in vitro, by trypsin and coagulation inhibitory activity. SDS-PAGE, reduced conditions, showed two polypeptide chains (heavy and light chains) linked by one disulphide bridge. The chains were separated by reversed phase chromatography aíter reduced and alquilated. The N-terminal sequence were performed on automated protein sequencer by Edman degradation and showed homology with Kunitz type inhibitors from Leguminosae. Molecular weight of inhibitor and its chains were determined by mass spectrometry (LC/ESI-MS System) and showed molecular weight of 19.570Da, 15.530Da and 4040Da, respectively. Circular dichroism spectroscopy showed SbKI is constituted predominantly by P elements and unordered structures. SbKI was stable over extreme ranges of pH (2-12) and temperature and the transition temperature 73.3\"C investigated by CD and fluorescence emission spectroscopies. Inhibition constants (Ki) were determined by typsin (Ki = 5.5 nM) and human plasmatic kallikrein (Ki = 1.1 mM)
Dawson, Sally. "Genetic variation at the plasminogen activator inhibitor-1 locus and its effect on plasminogen activator inhibitor-1 expression." Thesis, Imperial College London, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298676.
Full textMcLaren, Lorna J. "The mouse protein phosphatase inhibitor-1 gene." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/24958.
Full textMontgomerie, Harry. "Novel inhibitor chemistry for oilfield scale application." Thesis, University of Huddersfield, 2014. http://eprints.hud.ac.uk/id/eprint/24277/.
Full textDavies, Glyn Daniel. "Inhibitor studies on para-aminobenzoic acid synthase." Thesis, University of Cambridge, 2003. https://www.repository.cam.ac.uk/handle/1810/265461.
Full textMahmoodi, Niusha. "Indole prenyltransferases : mechanistic studies and inhibitor design." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/55872.
Full textScience, Faculty of
Chemistry, Department of
Graduate
Cho, Park 1975. "The Cap-binding inhibitor of translation, d4EHP /." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111819.
Full textEarly embryogenesis requires the activity of various maternal determinants called morphogens, whose spatial and temporal expressions are tightly regulated at the level of translation. Positional information encoded within these factors is thus important for the establishment of body polarity. For instance, in Drosophila, when maternal Caudal (Cad) and Hunchback (Hb) proteins are allowed to accumulate inappropriately in an embryo, anterior and abdominal segmentations are blocked. Hence, the precision of Cad and Hb expression domains is critical for normal development.
An eIF4E-related protein called eIF4E-Homologous protein (4EHP) was first described in 1998. However, the function, if any, of 4EHP in translation has been elusive, since it does not interact with any known initiation factors. In order to elucidate its biological function, the power of Drosophila genetics was used. In this thesis, I show that the Drosophila homolog of 4EHP (d4EHP) interacts with Bicoid (Bcd) and Brain tumor (Brat) proteins to inhibit the translation of maternal cad and hb mRNAs. Simultaneous interaction of d4EHP with the cap and Bcd or Brat results in mRNA circularization, which renders cad and hb mRNAs translationally inactive. This example of cap-dependent translational control that is not mediated by eIF4E defines a new paradigm for translational inhibition involving tethering of the mRNA 5' and 3' ends.
Sirry, Baheya. "Regulation of the translational inhibitor 4E-BP1." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79128.
Full textWe first decided to examine 4E-BP1 phosphorylation against the background of an embryonic lethal mutant of FRAP/mTOR, the flat-top mutant, in order to elucidate the effect of this point mutation on FRAP/mTOR function. Our results revealed that signalling leading to 4E-BP1 phosphorylation is impaired in these mutants.
We were then interested in establishing 4E-BP1's role in the cell cycle by examining its phosphorylation state during mitosis. This study was based on the finding that CAP-dependent translation is inhibited in mitotic cells. Using 2-dimensional gel electrophoresis we detected two new isoforms of 4E-BP1 during mitosis.
The above studies demonstrate the essential role of 4E-BP1 in mammalian development and the cell cycle, emphasizing the need to better understand mechanisms involved in its regulation.
Patient, Michaela Eileen. "Rcd, a ColE1-encoded cell division inhibitor." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309210.
Full textDuncan, S. J. "Structural studies on a p53-MDM2 inhibitor." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598682.
Full textPanahloo, Archia. "Plasminogen activator inhibitor-1 and cardiovascular risk." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286442.
Full textBevan, A. W. "Specificity of inhibitor binding to dihydrofolate reductase." Thesis, University College London (University of London), 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352532.
Full textPotter, Garrett. "Chemical synthesis of a mimetic heparanase inhibitor." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/chemical-synthesis-of-a-mimetic-heparanase-inhibitor(6802b624-c3c0-4209-9c6d-bbcebf8e2d0b).html.
Full textCampbell, A. F. "Protein engineering of chymotrypsin inhibitor II (C12)." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/46983.
Full text陳恒琦. "Studies on the Inhibitory Mechanism of Angiogenesis Inhibitor, endostatin." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/08355482627008954517.
Full text國立中山大學
生物科學研究所
89
Antiangiogenic tomor therapies have attracted intense interest for their broad-spectrum action, low toxicity, and in the case of direct endothelial targeting, and absence of drug resistance. Among the growing list of antiangiogenic agents, endostatin has attracted most attention and been under the spotlight of numerous debates. Like other angiogenesis inhibitors, endostatin is also a proteolytic fragment (~20 kDa) from an extracellular protein, collagen XVIII. It potently inhibits endothelial cell proliferation and angiogenesis, but has no cytotoxic effects on cencer cells. Above all, therapy of experimental cancer with endostatin in rodents leads to tumor dormancy and does not induce resistance. However, the exact mechanism on how endostatin inhibited endothelial cells proliferation remains largely unknown. We have cloned mouse endostatin cDNA from mice liver by RT-PCR. After verification by DNA sequencing, endostatin cDNA was subcloned in to E.coli expression vector to express and generate large quantities of recombinant GST-fused endostatin (GST-endostatin). Unlike His-tagged endostatin, GST-endostatin is soluble and capable of inhibiting various endothelial cell lines including HUVEC, EA.hy926 and BAEC with IC50~20nM. Flow cytometry analysis indicated GST-endostatin induced apoptosis in EA.hy926 cells toward chemoattractant bFGF with IC50~0.5nM. Further more, GST-endostatin inhibited in vivo angiogenesis in chicken chorioallantoic membrane and suppressed tumor growth in mice bearing Lewis lung carcinoma cells. After functional characterization of GST-Z endostatin, we decided to use GST-endostatin and EA.hy926 cells as a model system to study the inhibitory mechanism of endostatin in endothelial cells. By using fura-2 fluorescence probe, GST-endostatin was shown to elevate the cytosolic calcium in dose-dependent manner from extracellular source. Chelation of extracellular Ca2+by EGTA or inhibition of calcium channel by nifedipine abolished the cytotoxic effect endostatin, suggesting the calcium rise by endostatin play an important role in its inhibitory mechanism. Besides, endostatin also stimulated activity of a large- conductance calcium-activated potassium (Bkca) channel, further supporting endostatin initiated serial changes in ion channels activities in endothelial cells. Respiratory enzyme activities and endogenous ATP synthesis in endothelial cells were significantly inhibited by GST-endostatin treatment, indicating GST-endostatin depleted the energy source for endothelial cells. In summary, present study demonstrated GST-endostatin caused dramatic changes in electrophysiologic properties and decreased endogenous ATP synthesis in endothelial cells, which may participate in its inhibitory mechanism.
Chen, Heng-Chi James, and 陳恒琦. "Studies on the Inhibitory Mechanism of Angiogenesis Inhibitor, Endostatin." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/20681125193868341554.
Full text國立中山大學
生物科學系研究所
88
Antiangiogenic tomor therapies have attracted intense interest for their broad-spectrum action, low toxicity, and in the case of direct endothelial targeting, an absence of drug resistance. Among the growing list of antiangiogenic agents, endostatin has attracted most attention and been under the spotlight of numerous debates. Like other angiogenesis inhibitors, endostatin is also a proteolytic fragment (~20 kDa) from an extracellular protein, collagen XVIII. It potently inhibits endothelial cell proliferation and angiogenesis, but has no cytotoxic effects on cancer cells. Above all, therapy of experimental cancer with endostatin in rodents leads to tumor dormancy and does not induce resistance. However, the exact mechanism on how endostatin inhibited endothelial cells proliferation remains largely unknown. We have cloned mouse endostatin cDNA from mice liver by RT-PCR. After verification by DNA sequencing, endostatin cDNA was subcloned in to E.coli expression vector to express and generate large quantities of recombinant GST-fused endostatin (GST-endostatin). Unlike His-tagged endostatin, GST-endostatin is soluble and capable of inhibiting various endothelial cell lines including HUVEC, EA.hy926 and BAEC with IC50 ~ 20 nM. Flow cytometry analysis indicated GST-endostatin induced apoptosis in EA.hy926 cells. GST-endostatin also inhibited the cell migration of EA.hy926 cells toward chemoattractant bFGF with IC50 ~ 0.5 nM. Further more, GST-endostatin inhibited in vivo angiogenesis in chicken chorioallantoic membrane and suppressed tumor growth in mice bearing Lewis lung carcinoma cells. After functional characterization of GST-endostatin, we decided to use GST-endostatin and EA.hy926 cells as a model system to study the inhibitory mechanism of endostatin in endothelial cells. By using fura-2 fluorescence probe, GST-endostatin was shown to elevate the cytosolic calcium in dose-dependent manner from extracellular source. Chelation of extracellular Ca2+ by EGTA or inhibition of calcium channel by nifedipine abolished the cytotoxic effect endostatin, suggesting the calcium rise by endostatin play an important role in its inhibitory mechanism. Besides, endostatin also stimulated activity of a large- conductance calcium-activated potassium (Bkca) channel, further supporting endostatin initiated serial changes in ion channels activities in endothelial cells. Respiratory enzyme activities and endogenous ATP synthesis in endothelial cells were significantly inhibited by GST-endostatin treatment, indicating GST-endostatin depleted the energy source for endothelial cells. In summary, present study demonstrated GST-endostatin caused dramatic changes in electrophysiologic properties and decreased endogenous ATP synthesis in endothelial cells, which may participate in its inhibitory mechanism.
Hua, Tzu-Yu, and 華梓佑. "Structures of NP exonuclease-inhibitor complex reveal the unique inhibition mechanism by a covalent bond between cysteine and inhibitor." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/b95fht.
Full text國立交通大學
生物資訊及系統生物研究所
105
The Nucleoprotein exonuclease ( NP exonuclease ) of Lassa virus is involved in viral genomic RNA encapsidation, viral RNA synthesis and host immune evasion. NP exonuclease is constituted by N-terminal and C-terminal domains, of which the main function of N-terminal domain is to capture the 5' cap of mRNA in the host cell for carrying out transcription and replication of its own viral RNA; the C-terminal domain of NP exonuclease belongs to the DEDDh exonuclease family. The C-terminal domain is used to degrade pathogen associated molecular patterns generated by infecting host cells, like RNA; and thus further make IRF-3 transcription factor unable to enter the nucleus to induce interferon synthesis of immune system. If the highly conserved amino acids in the C-terminal domain are mutated, it will cause a decline in ability for Lassa virus to escape the host immune system, in other words, the C-terminal domain plays an important role in virus infections; hence the C-terminal domain of NP exonuclease can be used as a target for anti-viral drug research. In this study, we found the inhibitor candidates for NP exonuclease by literature reviews and computational molecular docking program. Through the nuclease activity assay, we identified several inhibitors with high inhibition efficiency, such as ATA、PCMPS、PHMB、PV6R and NCI35. We also determined the crystal structures of apo-NP exonuclease protein structure and NP exonuclease-PCMPS complex in which PCMPS was covalently bound to the cysteine ( C409 ) in the C-terminal domain, indicating that the covalent bond is critical to suppress the activation of NP exonuclease. Our biochemical experiments and two crystal structures reveal a unique inhibitory mechanism of PCMPS through covalent linkage to the NP exonuclease, and this work could be applied to the development of antiviral drugs.
Lapinska, Karolina Eva. "Anti-ovarian cancer effects of histone deacetylase inhibitors and calpain inhibitor." Thesis, 2016. https://hdl.handle.net/2144/14609.
Full text