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PEPTIDE DEFORMYLASE: A MODELING STUDY OF THE ACTIVE SITES OF PLANTS AND BACTERIA AND THE DESIGN, SYNTHESIS, AND BIOLOGICAL ACTIVITY ANALYSIS OF PEPTIDE-BASED INHIBITORSBarnes, Jonathan C. 01 January 2006 (has links)
All nascent polypeptides synthesized in bacteria, mitochondria, or chloroplastsstart with a N-formylmethionine. Peptide deformylase (PDF) is a mononuclear metal ionprotein that is responsible for removing the N-formyl group of nascent proteins found inbacteria and chloroplasts in order for them to become mature proteins. It is possible, asseen from the literature with actinonin, to chelate the enzyme's metal ion and inhibit thefunction of protein production essentially resulting in death of the bacteria, or plant. Thisstudy examines the active site of Arabidopsis thaliana (At) types of PDF (AtDEF1 andAtDEF2, respectively) as well as bacterial DEF2 using sequence alignments andcomputational modeling. This work also investigates the biological efficacy of designingand synthesizing inhibitors that mimic actinonin or the D1 substrate that will halt, orseverely retard, the activity of the PDF enzyme in vitro and in vivo. Through thisresearch, we were able to determine specific residues that were conserved amongst theplant DEF2 sequences that were present less than 20% of the time in plant DEF1 andbacteria DEF2. This data allowed us to hypothesize plant DEF2's substrate specificity aswell as a possible design that is selective towards plants and not bacteria. Also, based onpreliminary results, the novel thiol-actinonin chimera that was synthesized showedinhibition activity of AtDEF2 during in vitro enzyme assays.
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Testování zemních směrových ochran pomocí experimentálně získaných poruchových záznamů / Testing of Directional Earth Fault Protections Using The Experimentally Obtained Fault RecordsHolub, Martin January 2014 (has links)
Master thesis Testing of Directional Earth Fault Protections Using the Experimentally Obtained Fault Records deals with the protective functions of earth fault protections during earth faults in compensated medium voltage distribution network and their testing options. At the beginning of the thesis we charakterize operation of medium voltage distribution system in general. We begin with definition and characteristics of earth fault and its compartmentalization by the type of the fault, size of the transition resistance and duration. We also mention grounding methods of node winding transformer on medium voltage distribution network and we describe the most common of them in detail, i.e. network grouded through the arc suppression coil and its operation with automatic switching auxiliary resistor. In this part of the thesis we discuss the localization of the earth fault using passive static methods in compensated systems, which include wattmetric, admittance and conductance method. In next section we deal with the fault records stored in COMTRADE file format, its structure and all elements of its configuration and data file. We create and describe an example of converting ADF file format, recorded by Yokogawa oscilloscope fault recorder, into COMTRADE file format using Microsoft Excel program and M-File created in the MATLAB program. In the practical part we introduce workspace devices and software, which includes secondary testing equipment OMICRON CMC 256plus and its software OMICRON Test Universe with Advance Transplay test module, we further describe multifunctional earth fault protection RYo from PROTECTION & CONSULTING, s. r. o. and machine terminal REM 543 from ABB and their protective functions. The last part describes the actual testing of parallel connected earth fault protection with COMTRADE fault records by Advance Transplay test module in the OMICRON Test Universe. In the conclusion we describe evaluation of the suitability of each protective functions of earth fault protection in a variety of sizes the transition resistance at the earth fault location.
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