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- Member of: Barrett, The Honors College Thesis/Creative Project Collection
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Description
The FoF1 ATP synthase is a molecular motor critical to the metabolism of virtually all life forms, and it acts in the manner of a hydroelectric generator. The F1 complex contains an (αβ)3 (hexamer) ring in which catalysis occurs, as well as a rotor comprised by subunit-ε in addition to the coiled-coil and globular foot domains of subunit-γ. The F1 complex can hydrolyze ATP in vitro in a manner that drives counterclockwise (CCW) rotation, in 120° power strokes, as viewed from the positive side of the membrane. The power strokes that occur in ≈ 300 μsec are separated by catalytic dwells that occur on a msec time scale. A single-molecule rotation assay that uses the intensity of polarized light, scattered from a 75 × 35 nm gold nanorod, determined the average rotational velocity of the power stroke (ω, in degrees/ms) as a function of the rotational position of the rotor (θ, in degrees, measured in reference to the catalytic dwell). The velocity is not constant but rather accelerates and decelerates in two Phases. Phase-1 (0° - 60°) is believed to derive power from elastic energy in the protein. At concentrations of ATP that limit the rate of ATP hydrolysis, the rotor can stop for an ATP-binding dwell during Phase-1. Although the most probable position that the ATP-binding dwell occurs is 40° after the catalytic dwell, the ATP-binding dwell can occur at any rotational position during Phase-1 of the power stroke. Phase-2 of the power stroke (60° - 120°) is believed to be powered by the ATP-binding induced closure of the lever domain of a β-subunit (as it acts as a cam shaft against the γ-subunit). Algorithms were written, to sort and analyze F1-ATPase power strokes, to determine the average rotational velocity profile of power strokes as a function of the rotational position at which the ATP-binding dwell occurs (θATP-bd), and when the ATP-binding dwell is absent. Sorting individual ω(θ) curves, as a function of θATP-bd, revealed that a dependence of ω on
θATP-bd exists. The ATP-binding dwell can occur even at saturating ATP concentrations. We report that ω follows a distinct pattern in the vicinity of the ATP-binding dwell, and that the ω(θ) curve contains the same oscillations within it regardless of θATP-bd. We observed that an acceleration/deceleration dependence before and after the ATP-binding dwell, respectively, remained for increasing time intervals as the dwell occurred later in Phase-1, to a maximum of ≈ 40°. The results were interpreted in terms of a model in which the ATP-binding dwell results from internal drag at a variable position on the γε rotor.
θATP-bd exists. The ATP-binding dwell can occur even at saturating ATP concentrations. We report that ω follows a distinct pattern in the vicinity of the ATP-binding dwell, and that the ω(θ) curve contains the same oscillations within it regardless of θATP-bd. We observed that an acceleration/deceleration dependence before and after the ATP-binding dwell, respectively, remained for increasing time intervals as the dwell occurred later in Phase-1, to a maximum of ≈ 40°. The results were interpreted in terms of a model in which the ATP-binding dwell results from internal drag at a variable position on the γε rotor.
ContributorsBukhari, Zain Aziz (Author) / Frasch, Wayne D. (Thesis director) / Allen, James P. (Committee member) / Redding, Kevin (Committee member) / School of Molecular Sciences (Contributor) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
The goal of this research study was to empirically study a poster-based messaging campaign in comparison to that of a project-based learning approach in assessing the effectiveness of these methods in conveying the scope of biomedical engineering to upper elementary school students. For the purpose of this honors thesis, this research paper specifically reflects and analyzes the first stage of this study, the poster-based messaging campaign. 6th grade students received socially relevant messaging of juniors and seniors at ASU achieving their biomedical aspirations, and received information regarding four crucial themes of biomedical engineering via daily presentations and a website. Their learning was tracked over the course of the weeklong immersion program through a pre/post assessment. This data was then analyzed through the Wilcoxon matched pairs test to determine whether the change in biomedical engineering awareness was statistically significant. It was determined that a poster-based messaging campaign indeed increased awareness of socially relevant themes within biomedical engineering, and provided researchers with tangible ways to revise the study before a second round of implementation. The next stage of the study aims to explain biomedical engineering through engaging activities that stimulate making while emphasizing design-aesthetic appeal and engineering habits of mind such as creativity, teamwork, and communication.
ContributorsSwaminathan, Swetha Anu (Author) / Ganesh, Tirupalavanam (Thesis director) / Shrake, Scott (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The purpose of this creative project was to establish the foundation of an educational program that teaches financial literacy to the local homeless population. The name of this program is stillHUMAN. The project consisted of two parts, a needs analysis and a prototyping phase. The needs analysis was conducted at the Phoenix Rescue Mission Center, a faith-based homeless shelter that caters to male "clients", through written surveys and one-on-one interviews. Before interviewing the clients, the team acquired IRB approval as well as consent from the Center to carry out this study. These needs were then organized into a House of Quality. We concluded from Part 1 that we would need to create 3 - 7-minute-long video modules that would be available on an online platform and covered topics including professional development, budgeting, credit, and Internet literacy. In order to commence Part 2, each team member recorded a video module. These three videos collectively conveyed instruction regarding how to write a resume, use the Internet and fill out an application online, and how to budget money. These videos were uploaded to YouTube and shown to clients at Phoenix Rescue Mission, who were each asked to fill out a feedback survey afterwards. The team plans to use these responses to improve the quality of future video modules and ultimately create a holistic lesson plan that covers all financial literacy topics the clients desire. A website was also made to store future videos. The team plans to continue with this project post-graduation. Future tasks include creating and testing the a complete lesson plan, establishing a student organization at Arizona State University and recruiting volunteers from different disciplines, and creating an on-site tutoring program so clients may receive individualized attention. Once the lesson plan is demonstrated to be effective at Phoenix Rescue Mission, we plan to administer this lesson plan at other local homeless shelters and assess its efficacy in a non-faithbased and non-male environment. After a successful financial literacy program has been created, we aim to create lesson plans for other topics, including health literacy, human rights, and basic education. Ultimately stillHUMAN will become a sustainable program that unites the efforts of students and professionals to improve the quality of life of the homeless population.
ContributorsKim, Michael (Co-author) / Gulati, Guneet (Co-author) / Vanood, Aimen (Co-author) / Ganesh, Tirupalavanam (Thesis director) / Shrake, Scott (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Life Sciences (Contributor) / Department of Physics (Contributor) / Department of Psychology (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Lyme disease is a common tick-borne illness caused by the Gram-negative bacterium Borrelia burgdorferi. An outer membrane protein of Borrelia burgdorferi, P66, has been suggested as a possible target for Lyme disease treatments. However, a lack of structural information available for P66 has hindered attempts to design medications to target the protein. Therefore, this study attempted to find methods for expressing and purifying P66 in quantities that can be used for structural studies. It was found that by using the PelB signal sequence, His-tagged P66 could be directed to the outer membrane of Escherichia coli, as confirmed by an anti-His Western blot. Further attempts to optimize P66 expression in the outer membrane were made, pending verification via Western blotting. The ability to direct P66 to the outer membrane using the PelB signal sequence is a promising first step in determining the overall structure of P66, but further work is needed before P66 is ready for large-scale purification for structural studies.
ContributorsRamirez, Christopher Nicholas (Author) / Fromme, Petra (Thesis director) / Hansen, Debra (Committee member) / Department of Physics (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05