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A Step Towards Understanding Of The Molecular Basis Of Ligand Promiscuity In The Aminoglycoside Modifying Enzymes, Sherin R. Raval
A Step Towards Understanding Of The Molecular Basis Of Ligand Promiscuity In The Aminoglycoside Modifying Enzymes, Sherin R. Raval
Masters Theses
Aminoglycosides have proven very useful in the treatment of infections; lately their effectiveness has been greatly reduced due to increasing resistance. Among many known mechanisms of resistance to aminoglycosides, enzymatic modification is the most prevailing. More than 14 aminoglycoside -N3-acetyltransferases- a class of aminoglycoside modifying enzymes, are known today. This study focuses on a pair of acetyl transferases: The aminoglycoside-N3- acetyltransferase IIIb (AAC-IIIb) and the aminoglycoside-N3- acetyltransferase IIa (AAC-IIa). AAC-IIa and AAC-IIIb are very similar in their amino acid sequence and structure – yet they have a strong difference in their substrate selectivity, kinetic …
Localization Of Chemoreceptors In Azospirillum Brasilense., Anastasia Aksenova
Localization Of Chemoreceptors In Azospirillum Brasilense., Anastasia Aksenova
Masters Theses
In order to ensure their survival, bacteria must sense and adapt to a variety of environmental signals. Motile bacteria are able to orient their movement in a chemical gradient by chemotaxis. During chemotaxis, environmental signals are detected by chemotaxis receptors and are propagated via a signal transduction cascade to affect bacterial motility. In a model organism Escherichia coli, chemotaxis receptors, also called MCPs (for methyl-accepting chemotaxis proteins) sense changes in concentration gradients by making temporal comparisons about the chemical composition of their surroundings. Decreased attractant concentration or increased repellant concentration results in conformational changes in the MCPs that culminate …
Examining The Functional Consequences Of The Flexibility Of Aminoglycoside Phosphotransferase (3’)-Iiia, Katelyn Dawn Rosendall
Examining The Functional Consequences Of The Flexibility Of Aminoglycoside Phosphotransferase (3’)-Iiia, Katelyn Dawn Rosendall
Masters Theses
The use of aminoglycoside antibiotics began in 1940 with the discovery of streptomycin. The overuse and misuse of antibiotics has resulted in prevalent cases of antibiotic resistance. The most common source of aminoglycoside resistance is the presence of enzymes that covalently modify the antibiotics at specific locations. One such enzyme, APH(3′)-IIIa [the aminoglycoside phosphotransferase three prime three a] conveys resistance by transferring the γ-phosphate [gamma phosphate] from ATP [adenosine triphosphate] onto the 3′ [three prime] carbon of the aminoglycoside antibiotic sugar ring. APH(3′)-IIIa has been shown to be flexible in solution and this flexibility is proposed to be responsible for …
Engineering Of Photosystem I Attachment To Titanium Oxide Nanostructures Via Ferredoxin-Fusion Proteins, Tuo Zhu
Masters Theses
Ferredoxins (Fds) are iron-sulfur proteins that mediate electron transfer in a range of metabolic reactions. In the thylakoid membrane of photosynthetic organisms, Fd facilitates electron transfer from the stromal surface of photosystem I (PSI) to the ferredoxin Nicotinamide adenine dinucleotide phosphate oxidoreductase (FNR), which requires that Fd is capable of docking and transferring electrons between these two complexes. In applied photosynthesis, many efforts have been devoted towards re-directing these electrons into either a hydrogen-evolving catalyst or an electron-conducting semiconductor. In this study, the electrons from the PSI complex are directed to a titanium oxide (TiO2) electrode, and Fd …
Value-Added Lignin Based Carbon Fiber From Organosolv Fractionation Of Poplar And Switchgrass, Andreas Attwenger
Value-Added Lignin Based Carbon Fiber From Organosolv Fractionation Of Poplar And Switchgrass, Andreas Attwenger
Masters Theses
Carbon fibers have unique properties that include high strength, low density and excellent chemical and thermal resistance. However, they have a low level of utilization because of their high price; typically around $30/kg for an entry level polyacrylonitrile (PAN) based carbon fiber. Low-cost carbon fibers derived from lignin are currently being investigated at the University of Tennessee, because using lignin as a precursor could significantly reduce production costs. Lignins obtained from the pulp and paper and the emerging biofuel industries have the potential to be used for carbon fiber production, however, they are typically unsuitable because of the high levels …