Matching Items (593)
Filtering by
- Creators: School of Politics and Global Studies
- Resource Type: Text
Description
The transmembrane subunit (gp41) of the envelope glycoprotein of HIV-1 associates noncovalently with the surface subunit (gp120) and together they play essential roles in viral mucosal transmission and infection of target cells. The membrane proximal region (MPR, residues 649-683) of gp41 is highly conserved and contains epitopes of broadly neutralizing antibodies. The transmembrane (TM) domain (residues 684-705) of gp41 not only anchors the envelope glycoprotein complex in the viral membrane but also dynamically affects the interactions of the MPR with the membrane. While high-resolution X-ray structures of some segments of the MPR were solved in the past, they represent the pre-fusion and post-fusion conformations, most of which could not react with the broadly neutralizing antibodies 2F5 and 4E10. Structural information on the TM domain of gp41 is scant and at low resolution.
This thesis describes the structural studies of MPR-TM (residues 649-705) of HIV-1 gp41 by X-ray crystallography. MPR-TM was fused with different fusion proteins to improve the membrane protein overexpression. The expression level of MPR-TM was improved by fusion to the C-terminus of the Mistic protein, yielding ∼1 mg of pure MPR-TM protein per liter cell culture. The fusion partner Mistic was removed for final crystallization. The isolated MPR-TM protein was biophysically characterized and is a monodisperse candidate for crystallization. However, no crystal with diffraction quality was obtained even after extensive crystallization screens. A novel construct was designed to overexpress MPR-TM as a maltose binding protein (MBP) fusion. About 60 mg of MBP/MPR-TM recombinant protein was obtained from 1 liter of cell culture. Crystals of MBP/MPR-TM recombinant protein could not be obtained when MBP and MPR-TM were separated by a 42 amino acid (aa)-long linker but were obtained after changing the linker to three alanine residues. The crystals diffracted to 2.5 Å after crystallization optimization. Further analysis of the diffraction data indicated that the crystals are twinned. The final structure demonstrated that MBP crystallized as a dimer of trimers, but the electron density did not extend beyond the linker region. We determined by SDS-PAGE and MALDI-TOF MS that the crystals contained MBP only. The MPR-TM of gp41 might be cleaved during or after the process of crystallization. Comparison of the MBP trimer reported here with published trimeric MBP fusion structures indicated that MBP might form such a trimeric conformation under the effect of MPR-TM.
This thesis describes the structural studies of MPR-TM (residues 649-705) of HIV-1 gp41 by X-ray crystallography. MPR-TM was fused with different fusion proteins to improve the membrane protein overexpression. The expression level of MPR-TM was improved by fusion to the C-terminus of the Mistic protein, yielding ∼1 mg of pure MPR-TM protein per liter cell culture. The fusion partner Mistic was removed for final crystallization. The isolated MPR-TM protein was biophysically characterized and is a monodisperse candidate for crystallization. However, no crystal with diffraction quality was obtained even after extensive crystallization screens. A novel construct was designed to overexpress MPR-TM as a maltose binding protein (MBP) fusion. About 60 mg of MBP/MPR-TM recombinant protein was obtained from 1 liter of cell culture. Crystals of MBP/MPR-TM recombinant protein could not be obtained when MBP and MPR-TM were separated by a 42 amino acid (aa)-long linker but were obtained after changing the linker to three alanine residues. The crystals diffracted to 2.5 Å after crystallization optimization. Further analysis of the diffraction data indicated that the crystals are twinned. The final structure demonstrated that MBP crystallized as a dimer of trimers, but the electron density did not extend beyond the linker region. We determined by SDS-PAGE and MALDI-TOF MS that the crystals contained MBP only. The MPR-TM of gp41 might be cleaved during or after the process of crystallization. Comparison of the MBP trimer reported here with published trimeric MBP fusion structures indicated that MBP might form such a trimeric conformation under the effect of MPR-TM.
ContributorsGong, Zhen (Author) / Fromme, Petra (Thesis advisor) / Mor, Tsafrir (Thesis advisor) / Ros, Alexandra (Committee member) / Redding, Kevin (Committee member) / Arizona State University (Publisher)
Created2014
Description
Over the past decade, several high-value proteins have been produced using plant-based transient expression systems. However, these studies exposed some limitations that must be overcome to allow plant expression systems to reach their full potential. These limitations are the low level of recombinant protein accumulation achieved in some cases, and lack of efficient co-expression vectors for the production of multi-protein complexes. This study report that tobacco Extensin (Ext) gene 3' untranslated region (UTR) can be broadly used to enhance recombinant protein expression in plants. Extensin is the hydroxyproline-rich glycoprotein that constitutes the major protein component of cell walls. Using transient expression, it was found that the Ext 3' UTR increases recombinant protein expression up to 13.5- and 6-fold in non-replicating and replicating vector systems, respectively, compared to previously established terminators. Enhanced protein accumulation was correlated with increased mRNA levels associated with reduction in read-through transcription. Regions of Ext 3' UTR essential for maximum gene expression included a poly-purine sequence used as a major poly-adenylation site. Furthermore, modified bean yellow dwarf virus (BeYDV)-based vectors designed to allow co-expression of multiple recombinant genes were constructed and tested for their performance in driving transient expression in plants. Robust co-expression and assembly of heavy and light chains of the anti-Ebola virus monoclonal antibody 6D8, as well as E. coli heat-labile toxin (LT) were achieved with the modified vectors. The simultaneous co-expression of three fluoroproteins using the single replicon, triple cassette is demonstrated by confocal microscopy. In conclusion, this study provides an excellent tool for rapid, cost-effective, large-scale manufacturing of recombinant proteins for use in medicine and industry.
ContributorsRosenthal, Sun Hee (Author) / Mason, Hugh (Thesis advisor) / Mor, Tsafrir (Committee member) / Chang, Yung (Committee member) / Arntzen, Charles (Committee member) / Arizona State University (Publisher)
Created2012
Description
Plants are a promising upcoming platform for production of vaccine components and other desirable pharmaceutical proteins that can only, at present, be made in living systems. The unique soil microbe Agrobacterium tumefaciens can transfer DNA to plants very efficiently, essentially turning plants into factories capable of producing virtually any gene. While genetically modified bacteria have historically been used for producing useful biopharmaceuticals like human insulin, plants can assemble much more complicated proteins, like human antibodies, that bacterial systems cannot. As plants do not harbor human pathogens, they are also safer alternatives than animal cell cultures. Additionally, plants can be grown very cheaply, in massive quantities.
In my research, I have studied the genetic mechanisms that underlie gene expression, in order to improve plant-based biopharmaceutical production. To do this, inspiration was drawn from naturally-occurring gene regulatory mechanisms, especially those from plant viruses, which have evolved mechanisms to co-opt the plant cellular machinery to produce high levels of viral proteins. By testing, modifying, and combining genetic elements from diverse sources, an optimized expression system has been developed that allows very rapid production of vaccine components, monoclonal antibodies, and other biopharmaceuticals. To improve target gene expression while maintaining the health and function of the plants, I identified, studied, and modified 5’ untranslated regions, combined gene terminators, and a nuclear matrix attachment region. The replication mechanisms of a plant geminivirus were also studied, which lead to additional strategies to produce more toxic biopharmaceutical proteins. Finally, the mechanisms employed by a geminivirus to spread between cells were investigated. It was demonstrated that these movement mechanisms can be functionally transplanted into a separate genus of geminivirus, allowing modified virus-based gene expression vectors to be spread between neighboring plant cells. Additionally, my work helps shed light on the basic genetic mechanisms employed by all living organisms to control gene expression.
In my research, I have studied the genetic mechanisms that underlie gene expression, in order to improve plant-based biopharmaceutical production. To do this, inspiration was drawn from naturally-occurring gene regulatory mechanisms, especially those from plant viruses, which have evolved mechanisms to co-opt the plant cellular machinery to produce high levels of viral proteins. By testing, modifying, and combining genetic elements from diverse sources, an optimized expression system has been developed that allows very rapid production of vaccine components, monoclonal antibodies, and other biopharmaceuticals. To improve target gene expression while maintaining the health and function of the plants, I identified, studied, and modified 5’ untranslated regions, combined gene terminators, and a nuclear matrix attachment region. The replication mechanisms of a plant geminivirus were also studied, which lead to additional strategies to produce more toxic biopharmaceutical proteins. Finally, the mechanisms employed by a geminivirus to spread between cells were investigated. It was demonstrated that these movement mechanisms can be functionally transplanted into a separate genus of geminivirus, allowing modified virus-based gene expression vectors to be spread between neighboring plant cells. Additionally, my work helps shed light on the basic genetic mechanisms employed by all living organisms to control gene expression.
ContributorsDiamos, Andy (Author) / Mason, Hugh S (Thesis advisor) / Mor, Tsafrir (Committee member) / Hogue, Brenda (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2017
Description
This study asks the question: does gender-based discrimination exists within Arizona State University's Army Reserve Officer Training Corps (ROTC), and if so, what are the effects of such discrimination? Within this study, discrimination is defined as: the treatment or consideration of, or making a distinction in favor of or against, a person or thing based on the group, class, or category to which that person or thing belongs, rather than on individual merit. The researcher predicted that this study would show that gender-based discrimination operates within the masculine military culture of Army ROTC at ASU, resulting from women's hyper-visibility and evidenced by their lack of positive recognition and disbelief in having a voice in the program. These expectations were based on background research claiming that the token status of women in military roles causes them to be more heavily scrutinized, and they consequentially try to attain success by adapting to the masculine military culture by which they are constantly measured. For the purposes of this study, success is defined as: the attainment of wealth, favor, or eminence . This study relies on exploratory interviews and an online survey conducted with male and female Army ROTC cadets of all grade levels at Arizona State University. The interviews and survey collected demographic information and perspectives on individual experiences to establish an understanding of privilege and marginalization within the program. These results do support the prediction that women in Army ROTC at ASU face discrimination based on their unique visibility and lack of positive recognition and voice in the program. Likewise, the survey results indicate that race also has a significant impact on one's experience in Army ROTC, which is discussed later in this study in regard to needs for future research. ASU Army ROTC includes approximately 100 cadets, and approximately 30-40 of those cadets participated in this study. Additionally, the University of Arizona and the Northern Arizona University Army ROTC programs were invited to participate in this study and declined to do so, which would have offered a greater sample population. Nonetheless, the results of this research will be useful for analysis and further discussion of gender-equality in Army ROTC at Arizona State University.
ContributorsAllemang, Lindsey Ann (Author) / Wood, Reed (Thesis director) / Switzer, Heather (Committee member) / School of Politics and Global Studies (Contributor) / School of Social Transformation (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Genocide studies have traditionally focused on the perpetrator’s intent to eradicate a particular identity-based group, using the Holocaust as their model and point of comparison. Although some aspects of the Holocaust were undoubtedly unique, recent scholars have sought to challenge the notion that it was a singular phenomenon. Instead, they draw attention to a recurring pattern of genocidal events throughout history by shifting the focus from intent to structure. One particular branch of scholars seeks to connect the ideology and tactics of imperialism with certain genocidal events. These anti-imperialist genocide scholars concede that their model cannot account for all genocides, but still claim that it creates meaningful connections between genocides committed by Western colonialist powers and those that have occurred in a neoimperialist world order shaped according to Western interests. The latter includes genocides in postcolonial states, which these scholars believe were shaped by the scars of their colonial past, as well as genocides in which imperial hegemons assisted local perpetrators. Imperialist and former colonial powers have contributed meaningfully to all of these kinds of genocides, yet their contributions have largely been ignored due to their own influence on the creation of the current international order. Incorporating the anti-imperialist perspective into the core doctrine of genocide studies may lead to breakthroughs in areas of related policy and practice, such as prevention and accountability.
ContributorsParker, Ashleigh Mae (Author) / Thies, Cameron (Thesis director) / Sivak, Henry (Committee member) / School of Politics and Global Studies (Contributor) / School of Social Transformation (Contributor) / Department of English (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Political polarization is the coalescence of political parties -- and the individuals of which parties are composed -- around opposing ends of the ideological spectrum. Political parties in the United States have always been divided, however, in recent years this division has only intensified. Recently, polarization has also wound its way to the Supreme Court and the nomination processes of justices to the Court. This paper examines how prevalent polarization in the Supreme Court nomination process has become by looking specifically at the failed nomination of Judge Merrick Garland and the confirmations of now-Justices Neil Gorsuch and Brett Kavanaugh. This is accomplished by comparing the ideologies and qualifications of the three most recent nominees to those of previous nominees, as well as analysing the ideological composition of the Senate at the times of the individual nominations.
ContributorsJoss, Jacob (Author) / Hoekstra, Valerie (Thesis director) / Critchlow, Donald (Committee member) / Computer Science and Engineering Program (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
As the U.S. reckons with the reality of sexual assault and harassment in the wake of the #MeToo movement, it is particularly important to consider sexual assault in the military, an institution that is a massive employer and the face of the U.S. abroad. Media coverage is a catalyst for change, and the nature and scope of coverage is indicative of public and political attitudes. This thesis uses both quantitative and qualitative data to analyze characteristics of military sexual assault cases that complicate media coverage and to identify strengths and weaknesses of the media's approach to such stories. On the quantitative side, it takes advantage of nearly 600 case reports of sexual assault from U.S. military bases in Japan that were categorized to identify themes such as disposition outcomes, alcohol involvement and victim participation in investigations. Qualitatively, this thesis includes interviews with military officials, victims' advocates, journalists and other stakeholders that help to create a more holistic understanding of how media cover military sexual assault. Notably, this thesis finds that a lack of public interest in the military, a lack of congruency between military and civilian systems, and a highly complex hierarchy that limits journalists' access to military sources and data all complicate coverage. Drawing from these conclusions, it recommends that the media avoid episodic reporting, focus on personalizing stories in an institutional context, embrace accountability journalism and dedicate resources to pursuing complex investigations. It also acknowledges the important role of non-traditional media in the future of information sharing on the topic of military sexual assault.
ContributorsArmstrong, Mia Anne (Author) / Warner, Carolyn (Thesis director) / Gilger, Kristin (Committee member) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This paper addresses policy solutions for the continuing medical education of providers treating LGBTQ patients. As a population subject to significant health disparities, LGBTQ individuals are at risk of discrimination and harm when entering the medical context and, as such, require particular provider competence in approaches to care. This population is also vulnerable to distinctive medical needs which often position individuals as patients, making clinical interactions a key component of equality in social contexts. Through literature review and policy analysis, this paper addresses how systemic inequality has been propagated in the medical community and suggests an intervention in developing critical CME materials and requirements which seek to promote provider knowledge of best practices for the treatment of LGBTQ individuals. The ultimate policy suggestion incorporates existing policy promulgated at the state and professional organization level to fully respond to the challenges of informing providers of best practice in a meaningful, practicable manner. This policy specifies the importance of mandatory content-based learning hour requirements, in order to ensure that all providers meet a minimum level of competency in providing care to minority and at-risk populations, particularly the LGBTQ population. Moreover, it encompasses an understanding of the role and importance of outside organizations with subject-area expertise and endows such organizations with the power to interact with the policy and curriculum formation process. In so doing, it addresses many of the underlying gaps in provider education on this critical issue and promotes equity in health outcomes for all patients. Keywords: LGBTQ health, continuing medical education, health policy
ContributorsBlessinger, Kayla Nicole (Author) / White, Adrienne (Thesis director) / Coplan, Bettie (Committee member) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This thesis takes the form of a market research report with the goal of analyzing the implications of the United Kingdom (UK) leaving the European Union (EU) (known as “Brexit”) on London’s office commercial real estate market. The ultimate goal of this report is to make a prediction, firmly grounded in quantitative and qualitative research conducted over the past several months, as to the direction of London’s commercial real estate market going forward (post-Brexit). Within the commercial real estate sector, this paper narrows its focus to the office segment of the London market.
Understanding the political landscape is crucial to formulating a reasonable prediction as to the future of the London market. Aside from research reports and articles, our main insights into the political direction of Brexit come from our recordings from meetings in March of 2017 with two high-ranking members of Parliament and one member of the House of Lords—all of whom are members of the Tory Party (the meetings being held under the condition of anonymity). The below analysis will be followed by a discussion of the economics of Brexit, primarily focusing on the economic risks and uncertainties which have emerged after the vote, and which currently exist today. Such risks include the UK losing its financial passporting rights, weakening GDP and currency value, the potential for a reduction in foreign direct investment (FDI), and the potential loss of the service sector in the city of London due to not being able to access the European Single Market.
The report will shift focus to analyzing three competing viewpoints of the direction of the London market based on recordings from interviews of stakeholders in the London real estate market. One being an executive of one of the largest REITs in the UK, another being the Global Head of Real Estate at a top asset management firm, and another being a director at a large property consulting firm. The report includes these differing “sub-theses” in order to try to make sense of the vast market uncertainties post-Brexit as well as to contrast their viewpoints with where the market is currently and with the report’s investment recommendation.
The remainder of the report will consist of the methods used for analyzing market trends including how the data was modeled in order to make the investment recommendation. The report will analyze real estate and market metrics pre-Brexit, immediately after the vote, post-Brexit, and will conclude with future projections encapsulating the investment recommendation.
Understanding the political landscape is crucial to formulating a reasonable prediction as to the future of the London market. Aside from research reports and articles, our main insights into the political direction of Brexit come from our recordings from meetings in March of 2017 with two high-ranking members of Parliament and one member of the House of Lords—all of whom are members of the Tory Party (the meetings being held under the condition of anonymity). The below analysis will be followed by a discussion of the economics of Brexit, primarily focusing on the economic risks and uncertainties which have emerged after the vote, and which currently exist today. Such risks include the UK losing its financial passporting rights, weakening GDP and currency value, the potential for a reduction in foreign direct investment (FDI), and the potential loss of the service sector in the city of London due to not being able to access the European Single Market.
The report will shift focus to analyzing three competing viewpoints of the direction of the London market based on recordings from interviews of stakeholders in the London real estate market. One being an executive of one of the largest REITs in the UK, another being the Global Head of Real Estate at a top asset management firm, and another being a director at a large property consulting firm. The report includes these differing “sub-theses” in order to try to make sense of the vast market uncertainties post-Brexit as well as to contrast their viewpoints with where the market is currently and with the report’s investment recommendation.
The remainder of the report will consist of the methods used for analyzing market trends including how the data was modeled in order to make the investment recommendation. The report will analyze real estate and market metrics pre-Brexit, immediately after the vote, post-Brexit, and will conclude with future projections encapsulating the investment recommendation.
ContributorsHorn, Jonathan (Co-author) / Sidi, Adam (Co-author) / Bonadurer, Werner (Thesis director) / McDaniel, Cara (Committee member) / Department of Finance (Contributor) / School of Politics and Global Studies (Contributor) / Economics Program in CLAS (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
My name is Adriana Becerra and I am a student at the Walter Cronkite School of Journalism and Mass Communication at Arizona State University. In hoping to combine my two passions of journalism and film, for my Honors Undergraduate Thesis project I created my own film review website. My website is a complete review of the films that were nominated for the 2015 Oscars in the following categories: Best Picture, Animated Feature, Documentary Feature, Foreign Language, and Short Film Live Action. In all, I watched and reviewed a total of twenty-eight films based on acting, lighting, music, cinematography, costume/makeup/set design, writing, and visual effects. Over the course of nine months, I have watched, reviewed, and talked extensively about each film that I have reviewed. Though tedious at times, I thoroughly enjoyed completing my Undergraduate Thesis Project. I hope to continue critically looking at films, and possibly even incorporating film in my journalistic career.
ContributorsBecerra, Adriana Justina (Author) / Dodge, Nancie (Thesis director) / Russell, Dennis (Committee member) / School of Politics and Global Studies (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / Department of English (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05