Matching Items (83)
Description
Diacylglycerol kinase catalyses the ATP-dependent conversion of diacylglycerol to phosphatidic acid in the plasma membrane of Escherichia coli. The small size of this integral membrane trimer, which has 121 residues per subunit, means that available protein must be used economically to craft three catalytic and substrate-binding sites centred about the membrane/cytosol interface. How nature has accomplished this extraordinary feat is revealed here in a crystal structure of the kinase captured as a ternary complex with bound lipid substrate and an ATP analogue. Residues, identified as essential for activity by mutagenesis, decorate the active site and are rationalized by the ternary structure. The γ-phosphate of the ATP analogue is positioned for direct transfer to the primary hydroxyl of the lipid whose acyl chain is in the membrane. A catalytic mechanism for this unique enzyme is proposed. The active site architecture shows clear evidence of having arisen by convergent evolution.
ContributorsLi, Dianfan (Author) / Stansfeld, Phillip J. (Author) / Sansom, Mark S. P. (Author) / Keogh, Aaron (Author) / Vogeley, Lutz (Author) / Howe, Nicole (Author) / Lyons, Joseph A. (Author) / Aragao, David (Author) / Fromme, Petra (Author) / Fromme, Raimund (Author) / Basu, Shibom (Author) / Grotjohann, Ingo (Author) / Kupitz, Christopher (Author) / Rendek, Kimberley (Author) / Weierstall, Uwe (Author) / Zatsepin, Nadia (Author) / Cherezov, Vadim (Author) / Liu, Wei (Author) / Bandaru, Sateesh (Author) / English, Niall J. (Author) / Gati, Cornelius (Author) / Barty, Anton (Author) / Yefanov, Oleksandr (Author) / Chapman, Henry N. (Author) / Diederichs, Kay (Author) / Messerschmidt, Marc (Author) / Boutet, Sebastien (Author) / Williams, Garth J. (Author) / Seibert, M. Marvin (Author) / Caffrey, Martin (Author) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2015-12-17
Description
Phytochromes are a family of photoreceptors that control light responses of plants, fungi and bacteria. A sequence of structural changes, which is not yet fully understood, leads to activation of an output domain. Time-resolved serial femtosecond crystallography (SFX) can potentially shine light on these conformational changes. Here we report the room temperature crystal structure of the chromophore-binding domains of the Deinococcus radiodurans phytochrome at 2.1 Å resolution. The structure was obtained by serial femtosecond X-ray crystallography from microcrystals at an X-ray free electron laser. We find overall good agreement compared to a crystal structure at 1.35 Å resolution derived from conventional crystallography at cryogenic temperatures, which we also report here. The thioether linkage between chromophore and protein is subject to positional ambiguity at the synchrotron, but is fully resolved with SFX. The study paves the way for time-resolved structural investigations of the phytochrome photocycle with time-resolved SFX.
ContributorsEdlund, Petra (Author) / Takala, Heikki (Author) / Claesson, Elin (Author) / Henry, Leocadie (Author) / Dods, Robert (Author) / Lehtivuori, Heli (Author) / Panman, Matthijs (Author) / Pande, Kanupriya (Author) / White, Thomas (Author) / Nakane, Takanori (Author) / Berntsson, Oskar (Author) / Gustavsson, Emil (Author) / Bath, Petra (Author) / Modi, Vaibhav (Author) / Roy Chowdhury, Shatabdi (Author) / Zook, James (Author) / Berntsen, Peter (Author) / Pandey, Suraj (Author) / Poudyal, Ishwor (Author) / Tenboer, Jason (Author) / Kupitz, Christopher (Author) / Barty, Anton (Author) / Fromme, Petra (Author) / Koralek, Jake D. (Author) / Tanaka, Tomoyuki (Author) / Spence, John (Author) / Liang, Mengning (Author) / Hunter, Mark S. (Author) / Boutet, Sebastien (Author) / Nango, Eriko (Author) / Moffat, Keith (Author) / Groenhof, Gerrit (Author) / Ihalainen, Janne (Author) / Stojkovic, Emina A. (Author) / Schmidt, Marius (Author) / Westenhoff, Sebastian (Author) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2016-10-19
Description
Antibodies are essential for structural determinations and functional studies of membrane proteins, but antibody generation is limited by the availability of properly-folded and purified antigen. We describe the first application of genetic immunization to a structurally diverse set of membrane proteins to show that immunization of mice with DNA alone produced antibodies against 71% (n = 17) of the bacterial and viral targets. Antibody production correlated with prior reports of target immunogenicity in host organisms, underscoring the efficiency of this DNA-gold micronanoplex approach. To generate each antigen for antibody characterization, we also developed a simple in vitro membrane protein expression and capture method. Antibody specificity was demonstrated upon identifying, for the first time, membrane-directed heterologous expression of the native sequences of the FopA and FTT1525 virulence determinants from the select agent Francisella tularensis SCHU S4. These approaches will accelerate future structural and functional investigations of therapeutically-relevant membrane proteins.
ContributorsHansen, Debra (Author) / Robida, Mark (Author) / Craciunescu, Felicia (Author) / Loskutov, Andrey (Author) / Dorner, Katerina (Author) / Rodenberry, John-Charles (Author) / Wang, Xiao (Author) / Olson, Tien (Author) / Patel, Hetal (Author) / Fromme, Petra (Author) / Sykes, Kathryn (Author) / Biodesign Institute (Contributor) / Innovations in Medicine (Contributor) / Applied Structural Discovery (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor)
Created2016-02-24
Description
Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.
ContributorsNogly, Przemyslaw (Author) / Panneels, Valerie (Author) / Nelson, Garrett (Author) / Gati, Cornelius (Author) / Kimura, Tetsunari (Author) / Milne, Christopher (Author) / Milathianaki, Despina (Author) / Kubo, Minoru (Author) / Wu, Wenting (Author) / Conrad, Chelsie (Author) / Coe, Jesse (Author) / Bean, Richard (Author) / Zhao, Yun (Author) / Bath, Petra (Author) / Dods, Robert (Author) / Harimoorthy, Rajiv (Author) / Beyerlein, Kenneth R. (Author) / Rheinberger, Jan (Author) / James, Daniel (Author) / Deponte, Daniel (Author) / Li, Chufeng (Author) / Sala, Leonardo (Author) / Williams, Garth J. (Author) / Hunter, Mark S. (Author) / Koglin, Jason E. (Author) / Berntsen, Peter (Author) / Nango, Eriko (Author) / Iwata, So (Author) / Chapman, Henry N. (Author) / Fromme, Petra (Author) / Frank, Matthias (Author) / Abela, Rafael (Author) / Boutet, Sebastien (Author) / Barty, Anton (Author) / White, Thomas A. (Author) / Weierstall, Uwe (Author) / Spence, John (Author) / Neutze, Richard (Author) / Schertler, Gebhard (Author) / Standfuss, Jorg (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor) / Department of Chemistry and Biochemistry (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / School of Molecular Sciences (Contributor)
Created2016-08-22
Description
With the acknowledgement of Type 2 Diabetes as a disease that disproportionately affects the Latinx communities, this study is designed to look at the relationship between health literacy and diabetes awareness. This research was conducted using data from Dr. Felipe Castro's previous study on Latino Lifestyles for Diabetes Prevention. Multiple linear regressions were ran to find the correlation between certain measures and diabetes awareness. Major findings included seeing the positive relationship between education and diabetes awareness and the negative correlation between Behavior Intentions Self Monitoring and diabetes awareness. Further studies are required to see how different social factors impact an individual's ability to gain health literacy regarding Type 2 Diabetes.
ContributorsHuerta, Isabel (Author) / Castro, Felipe (Thesis director) / Lopez, Gilberto (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution & Social Change (Contributor) / School of Public Affairs (Contributor) / School of Life Sciences (Contributor)
Created2024-05
Description
Type 2 diabetes mellitus is the most common form that exists and has many variables that play into its development and diagnosis. This study looks at some of the factors that may have played an impact on people who are pre-diabetic or at risk of being pre-diabetic. Pre-diabetes can often serve as a warning sign for people and presents them with an opportunity for intervention before their condition worsens. However, it often goes unnoticed due to the lack of education regarding healthy living and making better quality-of-life decisions in Hispanic communities. The purpose of this study was to help identify patterns in how people from these communities manage their conditions and find techniques that can be replicated by others in order to improve health outcomes.
This study followed a mixed methods approach in order to gain a full understanding of the quantitative (QUAN) and qualitative (QUAL) aspects that may have an impact on diabetes. Data was collected using a questionnaire to analyze different aspects and lifestyles of the participants and an interview with probing questions regarding life decisions, beliefs, and expectations. The overarching research question was “How did varying levels of health motivation and healthful eating habits affect glycosylated hemoglobin levels (HbA1c) in Hispanic/Latinx populations who are at risk of or are pre-diabetic?”. With this, we can obtain a better understanding of certain key aspects that play a role in the development of diabetes.
A correlations matrix analysis was run to test how certain variables related and caused changes with one another. To analyze how these variables related specifically to HbA1c, our dependent variable, a multiple regression model analysis was used. It was found that the main contributors to elevated HbA1c levels were health motivation and age. A joint display analysis combined different levels of health motivation, QUAN data, and the responses to a focus question regarding efforts taken to improve one's condition, QUAL. This displayed a pattern of participants with higher health motivation showing efforts to reduce their diabetes risk and by contrast, low health motivation participants showing minimal to no efforts in changing behavior.
This study found that elevated HbA1c levels also come with higher health motivation which normally wouldn’t make sense. However, the participants from this study knew about their HbA1c levels before this survey was conducted which means that these people already knew about the dangers of their condition and may have been taking steps to mitigate further risk. This demonstrates the importance of developing education systems to help inform people about risk factors and symptoms to alert them of their condition.
It is common in Hispanic areas for people to cook high-fat foods, lard, or oil which often lead to an increased risk of diabetes. There is also a great difference in the amount of resources that Hispanic communities have for practicing healthy lifestyle habits and less effective self-monitoring that makes it difficult to recognize early signs of diabetes. Promoting interventions that help educate about the risks of diabetes could encourage great change in eating habits, activity levels, and overall health outcomes for people from Hispanic communities.
ContributorsZafar, Rehan (Author) / Castro, Felipe (Thesis director) / Kavouras, Stavros (Committee member) / Barrett, The Honors College (Contributor) / School of Humanities, Arts, and Cultural Studies (Contributor) / College of Health Solutions (Contributor)
Created2024-05
Description
This study utilized a Convergent Mixed Methods design to identify different expressions of resilience in response to a health/familial problem. The research aimed to determine which specific expressions of resilience were significantly associated with higher levels of resilience. The findings revealed two significant effects related to social support and persistence as expressions of resilience. The High Resilience group exhibited a higher proportion of individuals mentioning persistence and social support in their coping strategies. The study concluded that social support seeking is a major coping strategy among individuals with high resilience and suggested that healthcare providers, particularly nurses, should recommend and provide resources for clients to seek social support. Furthermore, the role of persistence highlights the importance of encouraging clients to set achievable goals, develop a plan, and monitor their progress to remain motivated in resolving their difficult health-related problem.
ContributorsJohn, Avery (Author) / Castro, Felipe (Thesis director) / Lober, Angela (Committee member) / Juarigue, Lisa (Committee member) / Barrett, The Honors College (Contributor) / Edson College of Nursing and Health Innovation (Contributor)
Created2023-05
Description
A leading chronic disease within the United States, type 2 diabetes mellitus (T2D) disproportionately affects the Latinx-American population. Given that prediabetes is closely correlated to the eventual development of T2D, this paper examines the effects of five sociopsychological variables - socioeconomic status, acculturation, education, exercise behavior, and high caloric intake - as associated with levels of glycosylated hemoglobin (A1c), among prediabetic Latinx adults to identify which of these five factors exhibits the strongest association, and is thereby the strongest risk factor for the development of T2D. Accordingly, the overarching research question for the study is the following: “Which of these five identified variables has the strongest correlation with levels of A1c among prediabetic Latinx adults, both men and women?” 35 cases of adult Latinx American individuals with a known history of prediabetes were analyzed to form the database for the study. Initial correlations matrices served as an exploratory analysis, and affirmed expected findings of a strongly negative correlation between each of the following three variables – household income, acculturation, and high caloric intake – and A1c levels. The revised final multiple regression model confirmed a negative correlation between acculturation and A1c levels, while also demonstrating a positive correlation between both health motivation and low-density lipoprotein (LDL) in regards to A1c levels. These observations demonstrate the need for further research to better understand these correlations, and thereby improve health disparities for the Latinx-American community as a whole.
ContributorsMagiyawala, Rashi (Author) / Castro, Felipe (Thesis director) / Lopez, Gilberto (Committee member) / Barrett, The Honors College (Contributor) / Dean, W.P. Carey School of Business (Contributor) / School of Transborder Studies (Contributor) / School of Life Sciences (Contributor) / School of Art (Contributor)
Created2024-05
Description
The present study, Examination of Parent-Child Relationships in Latino Families
investigated the relationship between early adolescent experiences on coping behaviors, as
determinants of present day depressive symptoms and resilience. Three multiple regression
models were conducted (Model 1) Predictors of Problem Solving Coping, (Model 2) Predictors
of Depressive Symptoms, (Model 3) Predictors of Resilience. Following this a cross tabulation
analysis was conducted to look at (Yes = Mention) and (No = No Mention) of Active Problem
Solving across 3 levels of Quality of Relationship with Father. This study found that (a) Quality
of Relationship with Father was a significant predictor of Problem Solving Coping Behavior.
Also, (a) Father Expectations and Problem Solving Coping Behavior in adolescence were
significant positive predictors of Resilience. This evidence suggests that Quality of Relationship
with Father in adolescence aids in the development of specific skills and capabilities for (a)
effective Problem Solving Coping Behaviors and (b) effective Expression of Resilience.
ContributorsCarbajal, Robert (Author) / Castro, Felipe (Thesis director) / Carlos Chavez, Fiorella (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2024-05
Description
The Walter Cronkite School of Journalism and Mass Communications stands as a "gold standard" of journalism education throughout the country. In my time at the school though, I found that some aspects in the whole of the curriculum were missing. I as well as several other friends became interested in production and the technical side of things. This seemed to be the direction we wanted to go and soon realized this played a crucial part in journalism. Although there is a studio production class and a studio production track through the immersive Cronkite News program, there is not much in between. This inspired me to take a look deeper into production skills and their place within a journalism education. The project is split into three main sections that dive into the ideas of teaching production skills and technical skills to journalism students and whether or not it is valuable. The first part is the background of the project and why this project came to be. The background section explores the inspiration for the project. The project continues with a look at job statistics and where the industry currently sits. This continues into the final section that contains personal stories and interviews with professionals in the field. This is a critical section to back up claims made through research and evaluation. There is a lot of personal experience and non-traditional research done through this project, but the assertions and conclusions made are clear. Through job statistics, personal stories, and interviews with professionals, this project examines how production could be taught in a traditional journalism program. These stories show that a journalism curriculum may not be the best place to teach production in depth, but that it still is an incredibly important part of the journalism world as a whole.
ContributorsHardy, Joseph Michael (Author) / Jacoby, Jim (Thesis director) / McJannet, Rob (Committee member) / College of Public Service and Community Solutions (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12