Matching Items (141)
Description
Serial femtosecond X-ray crystallography (SFX) using an X-ray free electron laser (XFEL) is a recent advancement in structural biology for solving crystal structures of challenging membrane proteins, including G-protein coupled receptors (GPCRs), which often only produce microcrystals. An XFEL delivers highly intense X-ray pulses of femtosecond duration short enough to enable the collection of single diffraction images before significant radiation damage to crystals sets in. Here we report the deposition of the XFEL data and provide further details on crystallization, XFEL data collection and analysis, structure determination, and the validation of the structural model. The rhodopsin-arrestin crystal structure solved with SFX represents the first near-atomic resolution structure of a GPCR-arrestin complex, provides structural insights into understanding of arrestin-mediated GPCR signaling, and demonstrates the great potential of this SFX-XFEL technology for accelerating crystal structure determination of challenging proteins and protein complexes.
ContributorsZhou, X. Edward (Author) / Gao, Xiang (Author) / Barty, Anton (Author) / Kang, Yanyong (Author) / He, Yuanzheng (Author) / Liu, Wei (Author) / Ishchenko, Andrii (Author) / White, Thomas A. (Author) / Yefanov, Oleksandr (Author) / Han, Gye Won (Author) / Xu, Qingping (Author) / de Waal, Parker W. (Author) / Suino-Powell, Kelly M. (Author) / Boutet, Sebastien (Author) / Williams, Garth J. (Author) / Wang, Meitian (Author) / Li, Dianfan (Author) / Caffrey, Martin (Author) / Chapman, Henry N. (Author) / Spence, John (Author) / Fromme, Petra (Author) / Weierstall, Uwe (Author) / Stevens, Raymond C. (Author) / Cherezov, Vadim (Author) / Melcher, Karsten (Author) / Xu, H. Eric (Author) / College of Liberal Arts and Sciences (Contributor) / School of Molecular Sciences (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / Department of Physics (Contributor)
Created2016-04-12
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
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
Dissolved organic matter (DOM) can have numerous effects on the water chemistry and the biological life within an aquatic system with its wide variety of chemical structures and properties. The composition of the dissolved carbon can be estimated by utilizing the fluorescent properties of some DOM such as aromatic amino acids and humic material. This experiment was used to observe how organic matter could influence hydrothermal systems, such as Sylvan Springs in Yellowstone National Park, USA. Using optical density at 600 nm (OD 600), excitation-emission matrix spectra (EEMS), and Illumina sequencing methods (16S rRNA gene sequencing), changes in dissolved organic matter (DOM) were observed based on long term incubation at 84ºC and microbial influence. Four media conditions were tested over a two-month duration to assess these changes: inoculated pine needle media, uninoculated pine needle media, inoculated yeast extract media, and uninoculated yeast extract media. The inoculated samples contained microbes from a fluid and sediment sample of Sylvan Spring collected July 23, 2018. Absorbance indicated that media containing pine needle broth poorly support life, whereas media containing yeast extract revealed a positive increase in growth. Excitation-Emission Matrix Spectra of the all media conditions indicated changes in DOM composition throughout the trial. There were limited differences between the inoculated and uninoculated samples suggesting that the DOM composition change in this study was dominated by the two-month incubation at 84ºC more than biotic processes. Sequencing performed on a sediment sample collected from Sylvan Spring indicated five main order of prokaryotic phyla: Aquificales, Desulfurococcales, Thermoproteales, Thermodesulfobacteriales, and Crenarchaeota. These organisms are not regarded as heterotrophic microbes, so the lack of significant biotic changes in DOM could be a result of these microorganisms not being able to utilize these enrichments as their main metabolic energy supply.
ContributorsKnott, Nicholas Joseph (Author) / Shock, Everett (Thesis director) / Hartnett, Hilairy (Committee member) / Till, Christy (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The number of cancer survivors in the United States is growing rapidly and it is expected to double by 2040. Arizona is nationally ranked with the 14th highest number of survivors, many of which experience a wide range of persisting medical complications that result from the cancer and associated treatment. Consequently, there is an increased need for services tailored to the health and wellness of survivors. Studies have shown that exercise rehabilitation is effective in improving the physical and mental health of this patient population. This project aimed to investigate the status of medically-based exercise rehabilitation for cancer survivors in Arizona. It focused on services offered by cancer treatment centers and cardiac rehabilitation clinics, with cardiac rehabilitation providing a possible delivery method for future cancer exercise rehabilitation. A directory of resources was compiled based on responses to structured telephone interviews with the cancer treatment centers (n=32) and cardiac rehabilitation clinics (n=34) within the state. The directory will serve as a resource for both patients and clinicians by identifying statewide related services that are available at the medical institutions and within the community. Results showed that 42.9% and 39.4% of the cancer treatment centers and cardiac rehabilitation clinics, respectively, offered exercise related services for cancer survivors. 78.6% of cancer centers stated that they refer cancer survivors to physical therapy, while only 35.7% refer survivors to community-based programs. Only 2 cardiac rehabilitation clinics, or 6%, offered preventative cardiology exercise consultations to cancer survivors. In conclusion, rehabilitative exercise resources for cancer survivors in Arizona were limited. Additional cancer rehabilitation efficacy studies are needed to further clarify evidence-based practice guidelines and provide direction for optimal methods of healthcare delivery. It is recommended that this directory remains current with routine updates in an effort to increase patient accessibility to care.
ContributorsHitt, Ellen (Author) / Scales, Robert (Thesis director) / Huberty, Jennifer (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
Description
Background:
The positive impacts of yoga on stress, pain, and chronic disease has recently led to the integration of yoga as part of physical therapy (PT) treatment. Due to the lack of training for PTs related to yoga, there is currently a need to provide knowledge and education about how to safely and easily implement therapeutic yoga (TY) as a complementary treatment approach.
Objective:
The purpose of this study was to assess the readiness of PTs (those who do not currently prescribe TY to patients) to integrate TY into treatment, and secondly, the feasibility (i.e., acceptability, demand, and practicality) of a 5-week online TY training to improve the readiness of PT’s to utilize TY in their practice.
Methods:
Licensed Physical Therapist’s (n=103) were recruited nationally through social media and email. Eligible and consented participants were asked to register in a 5-week online TY training course, Readiness for Integrating Yoga Therapeutics into Rehabilitation for PTs (intervention). PTs perceptions of TY and the role of safety and confidence in prescribing TY to patients were measured at baseline and post-intervention using a customized survey. Feasibility outcomes were measured after completion of the 5-week online training course with a survey. Feasibility was measured with acceptability, demand, and practicality. Our benchmarks included: (1) at least 70% of PTs would find the course acceptable, (2) at least 60% would finish the course (i.e., demand) and (3) there would be significant improvements in PTs perceptions of TY.
Results:
A total of 95 licensed PTs registered in the 5-week online TY training course, with 60 PTs (63%) completing the intervention and surveys. Of the PTs who completed the 5-week online training course, most PTs felt they were not ready (n=19/60, 31.7%) or somewhat ready (n=25/60, 41.7%) to integrate TY prior to taking the online training. Over half of PTs thought the online training was acceptable (n= 50/60, 83.3%) and finished the course (n=60/95, 63%). There were significant improvements in personal readiness to prescribe TY, safety prescribing TY, confidence to prescribe TY, current understanding/knowledge of TY and feeling adequately trained and educated to use some form of TY techniques with patients.
Conclusion:
Findings suggest a 5-week online TY training course is feasible in improving PTs readiness to prescribe TY, safety prescribing TY, confidence to prescribe TY, current understanding/knowledge of TY and feeling adequately trained and educated to use some form of TY techniques with patients. Future studies are proposed to test the effectiveness of TY training and education opportunities with PTs to further advance the adoption of TY into PT practice.
The positive impacts of yoga on stress, pain, and chronic disease has recently led to the integration of yoga as part of physical therapy (PT) treatment. Due to the lack of training for PTs related to yoga, there is currently a need to provide knowledge and education about how to safely and easily implement therapeutic yoga (TY) as a complementary treatment approach.
Objective:
The purpose of this study was to assess the readiness of PTs (those who do not currently prescribe TY to patients) to integrate TY into treatment, and secondly, the feasibility (i.e., acceptability, demand, and practicality) of a 5-week online TY training to improve the readiness of PT’s to utilize TY in their practice.
Methods:
Licensed Physical Therapist’s (n=103) were recruited nationally through social media and email. Eligible and consented participants were asked to register in a 5-week online TY training course, Readiness for Integrating Yoga Therapeutics into Rehabilitation for PTs (intervention). PTs perceptions of TY and the role of safety and confidence in prescribing TY to patients were measured at baseline and post-intervention using a customized survey. Feasibility outcomes were measured after completion of the 5-week online training course with a survey. Feasibility was measured with acceptability, demand, and practicality. Our benchmarks included: (1) at least 70% of PTs would find the course acceptable, (2) at least 60% would finish the course (i.e., demand) and (3) there would be significant improvements in PTs perceptions of TY.
Results:
A total of 95 licensed PTs registered in the 5-week online TY training course, with 60 PTs (63%) completing the intervention and surveys. Of the PTs who completed the 5-week online training course, most PTs felt they were not ready (n=19/60, 31.7%) or somewhat ready (n=25/60, 41.7%) to integrate TY prior to taking the online training. Over half of PTs thought the online training was acceptable (n= 50/60, 83.3%) and finished the course (n=60/95, 63%). There were significant improvements in personal readiness to prescribe TY, safety prescribing TY, confidence to prescribe TY, current understanding/knowledge of TY and feeling adequately trained and educated to use some form of TY techniques with patients.
Conclusion:
Findings suggest a 5-week online TY training course is feasible in improving PTs readiness to prescribe TY, safety prescribing TY, confidence to prescribe TY, current understanding/knowledge of TY and feeling adequately trained and educated to use some form of TY techniques with patients. Future studies are proposed to test the effectiveness of TY training and education opportunities with PTs to further advance the adoption of TY into PT practice.
ContributorsThompson, Abigail Ann (Co-author) / Thompson, Abigail (Co-author) / Huberty, Jennifer (Thesis director) / Taylor, Matthew (Committee member) / Ortiz, Alexis (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Abstract Objective: The purpose of this study was to determine the feasibility (e.g., practicality and demand) of a 4-week series of yoga classes in a homeless shelter. Participants: Five current residents of Central Arizona Shelter Services (CASS) and the Chief of Programming at CASS. Methods: Each shelter resident participated in a 5-minute interview answering questions regarding the demand of implementing a yoga program at CASS. The Chief of Programming participated in a 30-minute interview answering questions regarding the practicality of implementing a 4-week series yoga program at the homeless shelter. Results: CASS residents reported a strong desire to attend a yoga program. The Chief of Programming at CASS reported that implementing a yoga program would conflict with the overall goal of the shelter. Conclusion: Implementing a 4-week series yoga program is not feasible at CASS although there is a strong demand for a yoga program among the homeless population of the Phoenix metro area.
ContributorsSamuels, Jasmyne Angelique (Author) / Hart, Teresa (Thesis director) / Huberty, Jennifer (Committee member) / Pearl, Julia (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Finding life beyond Earth could change our understanding of life and habitability. The best place to look for life beyond Earth is Jupiter's moon, Europa. It has been estimated Europa may have a liquid, salt-water subsurface with 2 to 3 times the volume of all Earth's oceans. Knowing that all life requires water, it is in our best interest to explore Europa. This thesis explored the plausibility of life on Europa in four of its environments: on the surface, under the ice shell, in the liquid subsurface, and at the bottom of the liquid subsurface. Each of these environments were defined from science literature and compared to known Earth analogs. Europa's surface is not likely to support life, as there is not liquid water present. There is also extremely high radiation bombardment and extremely low surface temperatures that are estimated to be well out of the range for supporting life. It is more plausible that life could be under Europa's ice shell than on the surface. Under the surface, radiation exposure dramatically reduces. Researchers have found organisms on Earth that can live in similar environments as Europa's ice as well. These organisms require some interaction with liquid water though. Uncertainties about Europa's ice shell thickness and radiation load per depth it experiences, as well as there being limited research on organisms in ice environments, hinder us from definitively assessing the plausibility of life under the surface. The best environment on Europa to look for life on Europa is the subsurface. There remain a lot of uncertainties about the subsurface, however, that make it difficult to assess the plausibility of finding life. These uncertainties include its depth, water activity, salinity, temperature, pressure, and structure. This subsurface may be suitable for life, but until we can further understand the environment of the subsurface, we cannot make definite conclusions. As for assessing the plausibility of life at the bottom of Europa's subsurface, there is not much we know about this environment either. It has been suggested there may be hydrothermal vents, but no evidence has either supported or rejected this idea. Without a clear understanding of the environment at the bottom of the subsurface, the plausibility of life here cannot be definitively answered. It is apparent we need to further study Europa. In particular, we need to focus on understanding the subsurface. When the subsurface is better defined, we can better assess the plausibility of life being present. Fortunately, both NASA and the ESA are currently planning missions to Europa that are scheduled to launch in the 2020s.
ContributorsHoward, Cheyenne Whiffen (Author) / Farmer, Jack (Thesis director) / Shock, Everett (Committee member) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Recent research has confirmed and revealed many physical and mental benefits of yoga. The practice of yoga has spread throughout the western world, where it is widely used for the purpose of exercise and fitness. Due to its rise in popularity, there is a need for research regarding the energy expenditure required for different types of yoga. The majority of the literature cites yoga as being an effective exercise for light intensity activity, but there are not as many studies attempting to determine if there are postures and sequences that can meet the requirements for moderate physical activity. In addition, there is a need to validate mobile devices with which to measure energy expenditure (EE) that are compatible with the dynamic movements that occur during yoga. The purpose of this study was to measure energy expenditure of twenty-two yoga practitioners of varying experience during a 30-minute Vinyasa flow yoga practice and from this data collection determine: if an ashtanga-based vinyasa yoga class meets the criteria for moderate intensity physical activity, the reliability between the Actigraph and Oxycon Mobile and the validity of an Actigraph GT3X device worn on the hip in estimating energy expenditure for ashtanga-based vinyasa flow yoga. The Actigraph GT3X and the Oxycon mobile were used to measure energy expenditure. Mean values for energy expenditure recorded by the Oxycon and Actigraph were 3.19 ± 0.42 METs and 1.16 ± 0.23 METs respectively, exhibiting a significant difference in data collection. There was no correlation between the values recorded by the two devices, indicating that the Actigraph was not consistent with the Oxycon Mobile (previously validated for measurement of EE). Results of this study indicate that this Vinyasa flow yoga sequence does satisfy the criteria for moderate intensity physical activity as defined by ACSM with an average EE of 3.19 ± 0.42 METs, and that the Actigraph GT3X is not an accurate device for measurement of EE for yoga.
ContributorsHand, Lindsay Gabrielle (Author) / Huberty, Jennifer (Thesis director) / Buman, Matthew (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12