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PURIFICATION AND CRYSTALLIZATION OF D16/17 SPECTRlN REPEATS OF DYSTROPHIN
Title
PURIFICATION AND CRYSTALLIZATION OF D16/17 SPECTRlN REPEATS OF DYSTROPHIN
Creator
Tom, Tinku
Date
2012-12-26, 2012-12
Description
Muscular dystrophies are a group of genetic disorders characterized by progressive muscle weakness and wasting. Most of the dystrophies are...
Show moreMuscular dystrophies are a group of genetic disorders characterized by progressive muscle weakness and wasting. Most of the dystrophies are due to the anomalies in dystrophin or its associated proteins. Neuronal nitric oxide synthase (nNOS) is a vasodilator localized to the sarcolemma that acts in response to the increased metabolic rates during muscle contraction. nNOS localization is impaired in most Duchenne muscular dystrophies (DMD) cases. The nNOS is localized by both dystrophin and syntrophin acting together. The D16/17 spectrin repeats is the part of dystrophin that binds to nNOS. It was found that restoring the dystrophin nNOS interaction could ameliorate the effects of dystrophy in mdx mouse (mouse model for DMD). The goal of this project was to crystallize D16/17 in order to study the structural details of this polypeptide and its binding site to nNOS. The BL21 clones of D16/17 gene with a GST tag were cultured and lysed. Affinity chromatography was used to isolate the protein with the GST tag. The tag was enzymatically cleaved using thrombin and was purified from GST and other proteinsusing ion-exchange chromatography. Highly pure protein was obtained. The solution was stored in -800 C. Optimum well conditions for crystallization was found using the PEG ION-II crystallization kit from Hampton. Three well conditions were varied to find the conditions that yield best crystals.
M.S. in Molecular Biochemistry and Biophysics, December 2012
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COMMUNITY ENGAGEMENT AND COMMUNITY RESPONSE OF FIRST TIME CODE CONTRIBUTORS ON GITHUB
Title
COMMUNITY ENGAGEMENT AND COMMUNITY RESPONSE OF FIRST TIME CODE CONTRIBUTORS ON GITHUB
Creator
Heston, Matthew
Date
2014, 2014-05
Description
We collect data for 13,383 rst time code contributions from 45 projects on the website GitHub and analyze behavior of developers before...
Show moreWe collect data for 13,383 rst time code contributions from 45 projects on the website GitHub and analyze behavior of developers before submitting code as well as community response to code contributions. Our ndings di er from previous research on open source software communities and social theories of learning in communities of practice. We nd most users do not participate in GitHub peripheral activities before submitting code changes. We also nd that community response to these submitted code changes is a poor predictor of whether or not the code is accepted.
M.S. in Information Architecture, May 2014
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CHARACTERIZATION OF ASXL2 AS AN INTRINSICALLY DISORDERED PROTEIN
Title
CHARACTERIZATION OF ASXL2 AS AN INTRINSICALLY DISORDERED PROTEIN
Creator
Chen, Po-tao
Date
2013, 2013-12
Description
During development and differentiation, the transcription regulation plays an important rule. The Polycomb Group (PcG) and the Trithorax Group...
Show moreDuring development and differentiation, the transcription regulation plays an important rule. The Polycomb Group (PcG) and the Trithorax Group (TrxG) proteins are two protein families; they act by forming multiprotein complexes that regulate transcription by modifying chromatin configurations through histone methylation. The establishment or the maintenance mistakes of the correct chromatin configuration have been connected to several diseases, including leukemia and muscular dystrophy. The activities of PcG and TrxG proteins are regulated by a special group of proteins known as Enhancers of trithorax and Polycomb (ETP). The Additional sex combs-like 2 (Asxl2) protein, which is expressed from the gene called additional sex combs like 2 (Drosophila) (Asxl2), belongs to the Enhancer of trithorax and Polycomb group (ETP). The Asxl2 protein is highly expressed in heart during both development and in adult life. In a genetic study, the Asxl2-/- mice either died as neonates with congenital heart abnormalities or displayed progressive deterioration of ventricular function. Although Asxl2 protein is important, there have been no significant studies of the Asxl2 protein’s structure. Protein functions are determined to a considerable degree by structure, so the structural studies will provide valuable information on Asxl2. Failures of protein folding into native structure generally produce inactive or toxic proteins. Misfolded proteins are believed to be the causes of some neurodegenerative diseases, including Alzheimer’s and Parkinson's diseases. ix Through investigation in silico, it is known that the Asxl2 protein contains a large native unstructured region, and this result might indicate the Asxl2 is an intrinsically disordered protein (IDP). Most IDPs are known to have regulatory roles. Owing to their lack of folded structure, the intrinsically disordered proteins display a flexible and random-coil-like conformation under physiological conditions, and have several unique features. This suggests that distinctive methods will be required to characterize their structure. In order to understand the structure of Asxl2, we have expressed and purified an Asxl2 N-terminal truncation that contains a large native unstructured region of two important domains: the HARE-HTH domain and the Asx homology domain (ASXH). We have then used Circular Dichroism (CD) as a means of investigating the structure of Asxl2. The CD spectra have been measured over a wavelength range from 250 nm to 190 nm at various temperatures, with and without Asxl2’s physiological binding partner, the ubiquity carboxyl-terminal hydrolase BAP1 (Bap1) protein in order to test the hypothesis that Asxl2 is an IDP.
M.S. in Molecular Biochemistry and Biophysics, December 2013
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EFFICIENCY OF PATENT CONTRACTS
Title
EFFICIENCY OF PATENT CONTRACTS
Creator
Liang, Shao-huai
Date
2014, 2014-05
Description
This thesis attempts to analyze the incentive compatible (IC) region for the royalty contract in an innovation context. It also describes the...
Show moreThis thesis attempts to analyze the incentive compatible (IC) region for the royalty contract in an innovation context. It also describes the contracts that induce the licensee and the patentee to obtain the maximum pro t when using this licensing contract. We analyze the IC region for cost-reducing innovations " and royalty ratios in two situations: the non-drastic innovation and the drastic innovation. We also nd when licensing occurs, there is an e ciency loss. However, the IC region can limit the e ciency loss. Then, we extend our results to a two-stage game in order to check whether the royalty contract is still a good contract for both the licensee and the patentee from a pro t perspective. In stage two, when the size of innovation is smaller than the size of innovation in stage one, royalty contracts are inferior to other contracts. However, when the size of innovation in stage two is greater than that in stage one, the royalty contract is an improvement over other contracts.
PH.D in Management Science, May 2014
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