Matching Items (207)
Description
Quercetin 2,3-dioxygenase from Bacillus subtilis has been identified and characterized as the first known prokaryotic quercetinase. This enzyme catalyzes the cleavage of the O-heteroaromatic ring of the flavonol quercetin to the corresponding depside and carbon monoxide. The first quercetinase was characterized from a species of Aspergillus genus, and was found to contain one Cu2+ per subunit. For many years, it was thought that the B. subtilis quercetinase contained two Fe2+ ions per subunit; however, it has since been discovered that Mn2+ is a much more likely cofactor. Studies of overexpressed bacterial enzyme in E. coli indicated that this enzyme may be active with other metal ions (e.g. Co2+); however, the production of enzyme with full metal incorporation has only been possible with Mn2+. This study explores the notion that metal manipulation after translation, by partially unfolding the enzyme, chelating the metal ions, and then refolding the protein in the presence of an excess of divalent metal ions, could generate enzyme with full metal occupancy. The protocols presented here included testing for activity after incubating purified quercetinase with EDTA, DDTC, imidazole and GndHCl. It was found that the metal chelators had little to no effect on quercetinase activity. Imidazole did appear to inhibit the enzyme at concentrations in the millimolar range. In addition, the quercetinase was denatured in GndHCl at concentrations above 1 M. Recovering an active enzyme after partial or complete unfolding proved difficult, if not impossible.
ContributorsKrojanker, Elan Daniel (Author) / Francisco, Wilson (Thesis director) / Allen, James P. (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2014-05
Description
In the United States, a dispute has arisen over the safety and need for vaccination, particularly in regard to compulsory vaccination laws. New outlets and social media sites publish countless reports about the dangers of vaccines or of known adverse reactions as well as imagined or unproven worries. Individuals' rights to choose to get vaccinated or allow their children to be vaccinated comes to direct conflict with measures needed to protect communities from preventable viral diseases. The controversy surrounding vaccines is not new, nor necessarily are the fundamental reasons for skepticism. Looking back through the history of vaccines as a medical tool, the evolution of the controversy can be observed taking place with each new historical context, scientific development, and social conditions. Despite scientific research and assurances of vaccine safety, opposition and unease about vaccination appear to take Looking individually at the development and distribution of the smallpox (variola virus), polio (poliovirus) and human papilloma virus(HPV) vaccines, concerns regarding the violation of personal rights, safety of vaccines themselves, and social stigmas and connotations surrounding vaccines can be seen to evolve and change. Due to the way doubt can manifest in different ways over time, it may be impossible to fully end the vaccine debate. However, nderstanding the sociological factors behind anti-vaccine sentiment may allow healthcare professionals to work with concerned people with a particular care to address these visceral and sometimes irrational fears surrounding vaccination.
ContributorsStevens, Luke Christian (Author) / Jacobs, Bertram (Thesis director) / Washo-Krupps, Delon (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
In Mexico, the female adolescent population is made up from two groups, single women and married or cohabitating women. Throughout the past decade there has been an increase in the fertility rate amongst the adolescent population in the state of Sonora. Several factors were analyzed to determine their impact on adolescent fertility rate and unplanned pregnancies but ultimately it was found that sexual education was the most influential factor. Comprehensive sexual education has been found to decrease the number of adolescent pregnancies in schools or cities where that curriculum is taught. Many experts believe that this occurs because adolescents are better educated in the proper usage of contraception. Increased contraceptive use directly causes a decrease in unplanned pregnancy rate. With respect to Mexico, it was found that comprehensive sexual education is taught in Sonora but there is no standardized program. Few institutions provide comprehensive sexual education and the programs range between a level 0 and level 3 with respect to the strictness of the abstinence only curricula. Four interviews were conducted between December of 2013 and March of 2014. The purpose of the interviews was to gain a better understanding about how sexual education is perceived in Hermosillo, Sonora, Mexico and what sort of programs are available to adolescents. The questions that comprised the interview consisted of three general parts: background, demographics and sexual education. The interviewees were selected based on their level of expertise reproductive health among adolescents. Two programs were selected for research: Programa Gente Joven (PGJ) and Vive Prevenido. Based on research and data analysis several conclusions were reached. The average age a Mexican woman first has sex, gets married and has her first child within less than 5 years starting in their adolescence. Many years pass between the age of a woman's first childbirth and when she first uses contraception. This is caused by an unmet or unsatisfied need for contraception where the national level is higher than that of Sonora. With respect to sexual education the Guttmacher Institute data suggests that comprehensive sexual education is more effective than abstinence only education. And finally, the experts interviewed all agreed that comprehensive sexual education is what should be taught on a state wide level. The views and opinions of these four interviewees do not reflect those of all who work with adolescents. To gain a more generalized idea on the situation surrounding unplanned pregnancies in adolescents more interviews would need to be conducted. This project was purely exploratory and does not aim to analyze or evaluate either program.
ContributorsGalaz, Mayra Alejandra (Author) / Garcia Perez, Maria (Thesis director) / Lara-Valencia, Francisco (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
microRNAs (miRNAs) are short ~22nt non-coding RNAs that regulate gene output at the post-transcriptional level. Via targeting of degenerate elements primarily in 3'untranslated regions (3'UTR) of mRNAs, miRNAs can target thousands of varying genes and suppress their protein translation. The precise mechanistic function and bio- logical role of miRNAs is not fully understood and yet it is a major contributor to a pleth- ora of diseases, including neurological disorders, muscular disorders, and cancer. Cer- tain model organisms are valuable in understanding the function of miRNA and there- fore fully understanding the biological significance of miRNA targeting. Here I report a mechanistic analysis of miRNA targeting in C. elegans, and a bioinformatic approach to aid in further investigation of miRNA targeted sequences. A few of the biologically significant mechanisms discussed in this thesis include alternative polyadenylation, RNA binding proteins, components of the miRNA recognition machinery, miRNA secondary structures, and their polymorphisms. This thesis also discusses a novel bioinformatic approach to studying miRNA biology, including computational miRNA target prediction software, and sequence complementarity. This thesis allows a better understanding of miRNA biology and presents an ideal strategy for approaching future research in miRNA targeting.
ContributorsWeigele, Dustin Keith (Author) / Mangone, Marco (Thesis director) / Katchman, Benjamin (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-12
Description
Bacteria have been shown to possess a large array of regulatory mechanisms to not just respond to a diverse array of environmental stresses, but to injurious artificial proteins as well. A previous investigation introduced DX, a man-made ATP sequestering protein into Escherichia coli (E. coli) which resulted in the formation of novel endoliposome structures and induced a viable but non-culturable state (VBNC) that was not easily reversed. It was hypothesized that the broadly conserved bacterial stringent response pathway may have been responsible for the observed phenotypic changes. With the goal of unveiling the molecular mechanism behind this novel response, changes in cellular morphology and physiology upon DX expression were assessed in a population of E. coli encoding a dysfunctional relA gene, one of the two genes controlling the induction of the stringent response. It was ultimately shown that RelA directly contributed to cellular filamentation, endoliposome structure formation, and the induction of a VBNC state. While the stringent response has been extensively shown to induce a VBNC state, to our knowledge, relA has not yet been shown to induce filamentation or coordinate the formation of endoliposome structures in bacteria. As the stringent response has been shown to be increasingly involved in antibiotic tolerance, this study provided an exciting opportunity to further characterize this adaptive response pathway to aid in the future development of novel therapeutics. In addition to this, this study continued to highlight that the DX protein may serve one of the first tools to allow for the direct selection of bacteria in a VBNC state by morphologically distinguishing non-culturable cells through cellular filamentation.
ContributorsFrost, Fredrick Charles (Author) / Chaput, John (Thesis director) / Wachter, Rebekka (Committee member) / Korch, Shaleen (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2014-12
Description
The Roller Derby Club at Arizona State University became a student organization in the fall of 2013. They became a practicing team known as the Derby Devils in the spring of 2014. This project documents the creation and development a collegiate roller derby team as they go from a student organization to an athletic team. Collegiate roller derby is still in its infant stages and therefore the purpose of this project is to provide a guide for future collegiate roller derby teams as well as other athletic teams.
ContributorsLee, Alisa Yulim (Author) / Looser, Devoney (Thesis director) / Hultsman, Wendy (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / Department of Chemistry and Biochemistry (Contributor) / W. P. Carey School of Business (Contributor)
Created2014-12
Description
Repeating tiles made of DNA were used to try to form an indefinitely large structure. Both the tiles and structure were 2D. Two different patterns were tested, one corrugated and one not. Corrugation means that the tiles alternated between facing up and facing down, canceling out any curvature to the tile and creating a slightly corrugated but largely 2D pattern. Annealing methods were also experimented with. Annealing the structure in two, separate steps as opposed to one was tested. Another experiment was comparing cyclic versus linear annealing. A linear decrease in temperatures defines the linear annealing, and a cyclic method involved a linear drop to a certain temperature, followed by a slight increase in temperature and cooling back down again. This cycle is done several times before it continues linear cool down. It was seen that both corrugated and non-corrugated structures could be made. In both cases tiles that make up a larger section of the overall pattern were more successful. This is especially important for the non-corrugated pattern. Linear and 2step annealing methods seem to yield the best results.
ContributorsHunt, Ashley Elizabeth (Author) / Yan, Liu (Thesis director) / Yan, Hao (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
Continuing work has been done on a novel class of anti-cancer drugs employing a vinylogous extended amidine system functionalized into benzimidazole ring. Three new derivatives, utilizing a true sugar mimic at the N1-position, have been synthesized. Compounds 6-amino-1-[2-(2-hydroxyethoxy)ethyl-4-imino-2,5-dimethyl-1H-benzimidazole- 7-one (5), 6-amino-1-[2-(2-hydroxysulfonoethoxy)ethyl-4-imino-2,5-dimethyl-1H-benzimidazole-7-one (6), and 6-amino-1-[2-(2-hydroxysulfonoethoxy)ethyl-4-methylimino-2,5-dimethyl-1H-benzimidazole-7-one (7) have been synthesized utilizing similar protocols used in the synthesis of previously screened anti-tumor drugs produced by this laboratory. Compounds (5) and (6) have undergone screening similar to the National Cancer Institute’s (NCIs) Developmental Therapeutic Program (DTP), performed by Dr. Dan LaBarbera at the University of Boston. Both compounds show high cytotoxicity, with complete cell death at 5 µM and bioactive concentrations in the low nanomolar concentrations; more complete data is forthcoming. The proposed mechanism of action is through inhibition of p90RSK 1-2 which is responsible for the phosphorylation of Bcl-2 associated death promoter (BAD), a key metabolite in directing the onset of apoptosis. Future directions of next generation derivatives include modifying the 2-position of the benzimidazole ring into a halogenating or alkylating agent and possibly replacing the methanesulfonate with a phosphate group. This research is being published in the Journal of Medicinal Chemistry.
ContributorsMorrison, Zachary Tyler (Author) / Skibo, Edward (Thesis director) / Lefler, Scott (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2014-05
Description
Photosynthesis is a critical process that fixes the carbon utilized in cellular respiration. In higher plants, the immutans gene codes for a protein that is both involved in carotenoid biosynthesis and plastoquinol oxidation (Carol et al 1999, Josse et al 2003). This plastoquinol terminal oxidase (PTOX) is of great interest in understanding electron flow in the plastoquinol pool. In order to characterize this PTOX, polyclonal antibodies were developed. Expression of Synechococcus WH8102 PTOX in E. coli provided a useful means to harvest the protein required for antibody production. Once developed, the antibody was tested for limit of concentration, effectiveness in whole cell lysate, and overall specificity. The antibody raised against PTOX was able to detect as low as 10 pg of PTOX in SDS-PAGE, and could detect PTOX extracted from lysed Synechococcus WH8102. The production of this antibody could determine the localization of the PTOX in Synechococcus.
ContributorsKhan, Mohammad Iqbal (Author) / Moore, Thomas (Thesis director) / Redding, Kevin (Committee member) / Roberson, Robert (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
Overexpression of AVP1 (Arabidopsis vacuolar pyrophosphatase), a type I H+ pyrophosphatase, results in greater biomass, possibly due to a function in sucrose transport within the phloem. Overexpression of the phloem lipid-associated family protein (PLAFP) was shown to increase the number of vascular bundles in Arabidopsis. Could these two phenotypes complement one another additively? In this work, double mutants overexpressing both AVP1 and PLAFP were characterized. These double mutants have enhanced biomass, greater leaf area, and a larger number of vascular bundles than the single mutant lines. Overexpression of PLAFP does not result in any increase in rhizosphere acidification capacity.
ContributorsWilson, Sean (Co-author) / Furstenau, Tara (Co-author) / Gaxiola, Roberto (Thesis director) / Mason, Hugh (Committee member) / Wojciechowski, Martin (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2014-05