Matching Items (61)
130306-Thumbnail Image.png
Description
Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals

Serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs) enables high-resolution protein structure determination using micrometre-sized crystals at room temperature with minimal effects from radiation damage. SFX requires a steady supply of microcrystals intersecting the XFEL beam at random orientations. An LCP–SFX method has recently been introduced in which microcrystals of membrane proteins are grown and delivered for SFX data collection inside a gel-like membrane-mimetic matrix, known as lipidic cubic phase (LCP), using a special LCP microextrusion injector. Here, it is demonstrated that LCP can also be used as a suitable carrier medium for microcrystals of soluble proteins, enabling a dramatic reduction in the amount of crystallized protein required for data collection compared with crystals delivered by liquid injectors. High-quality LCP–SFX data sets were collected for two soluble proteins, lysozyme and phycocyanin, using less than 0.1 mg of each protein.
ContributorsFromme, Raimund (Author) / Ishchenko, Andrii (Author) / Metz, Markus (Author) / Roy Chowdhury, Shatabdi (Author) / Basu, Shibom (Author) / Boutet, Sebastien (Author) / Fromme, Petra (Author) / White, Thomas A. (Author) / Barty, Anton (Author) / Spence, John (Author) / Weierstall, Uwe (Author) / Liu, Wei (Author) / Cherezov, Vadim (Author) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor)
Created2015-08-04
130308-Thumbnail Image.png
Description
Serial femtosecond crystallography (SFX) has opened a new era in crystallo­graphy by permitting nearly damage-free, room-temperature structure determination of challenging proteins such as membrane proteins. In SFX, femtosecond X-ray free-electron laser pulses produce diffraction snapshots from nanocrystals and microcrystals delivered in a liquid jet, which leads to high protein consumption.

Serial femtosecond crystallography (SFX) has opened a new era in crystallo­graphy by permitting nearly damage-free, room-temperature structure determination of challenging proteins such as membrane proteins. In SFX, femtosecond X-ray free-electron laser pulses produce diffraction snapshots from nanocrystals and microcrystals delivered in a liquid jet, which leads to high protein consumption. A slow-moving stream of agarose has been developed as a new crystal delivery medium for SFX. It has low background scattering, is compatible with both soluble and membrane proteins, and can deliver the protein crystals at a wide range of temperatures down to 4°C. Using this crystal-laden agarose stream, the structure of a multi-subunit complex, phycocyanin, was solved to 2.5 Å resolution using 300 µg of microcrystals embedded into the agarose medium post-crystallization. The agarose delivery method reduces protein consumption by at least 100-fold and has the potential to be used for a diverse population of proteins, including membrane protein complexes.
ContributorsConrad, Chelsie (Author) / Basu, Shibom (Author) / James, Daniel (Author) / Wang, Dingjie (Author) / Schaffer, Alexander (Author) / Roy Chowdhury, Shatabdi (Author) / Zatsepin, Nadia (Author) / Aquila, Andrew (Author) / Coe, Jesse (Author) / Gati, Cornelius (Author) / Hunter, Mark S. (Author) / Koglin, Jason E. (Author) / Kupitz, Christopher (Author) / Nelson, Garrett (Author) / Subramanian, Ganesh (Author) / White, Thomas A. (Author) / Zhao, Yun (Author) / Zook, James (Author) / Boutet, Sebastien (Author) / Cherezov, Vadim (Author) / Spence, John (Author) / Fromme, Raimund (Author) / Weierstall, Uwe (Author) / Fromme, Petra (Author) / Department of Chemistry and Biochemistry (Contributor) / Biodesign Institute (Contributor) / Applied Structural Discovery (Contributor) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor) / School of Molecular Sciences (Contributor)
Created2015-06-30
130309-Thumbnail Image.png
Description
Lipidic cubic phases (LCPs) have emerged as successful matrixes for the crystallization of membrane proteins. Moreover, the viscous LCP also provides a highly effective delivery medium for serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs). Here, the adaptation of this technology to perform serial millisecond crystallography (SMX) at more

Lipidic cubic phases (LCPs) have emerged as successful matrixes for the crystallization of membrane proteins. Moreover, the viscous LCP also provides a highly effective delivery medium for serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs). Here, the adaptation of this technology to perform serial millisecond crystallography (SMX) at more widely available synchrotron microfocus beamlines is described. Compared with conventional microcrystallography, LCP-SMX eliminates the need for difficult handling of individual crystals and allows for data collection at room temperature. The technology is demonstrated by solving a structure of the light-driven proton-pump bacteriorhodopsin (bR) at a resolution of 2.4 Å. The room-temperature structure of bR is very similar to previous cryogenic structures but shows small yet distinct differences in the retinal ligand and proton-transfer pathway.
ContributorsNogly, Przemyslaw (Author) / James, Daniel (Author) / Wang, Dingjie (Author) / White, Thomas A. (Author) / Zatsepin, Nadia (Author) / Shilova, Anastasya (Author) / Nelson, Garrett (Author) / Liu, Haiguang (Author) / Johansson, Linda (Author) / Heymann, Michael (Author) / Jaeger, Kathrin (Author) / Metz, Markus (Author) / Wickstrand, Cecilia (Author) / Wu, Wenting (Author) / Bath, Petra (Author) / Berntsen, Peter (Author) / Oberthuer, Dominik (Author) / Panneels, Valerie (Author) / Cherezov, Vadim (Author) / Chapman, Henry (Author) / Schertler, Gebhard (Author) / Neutze, Richard (Author) / Spence, John (Author) / Moraes, Isabel (Author) / Burghammer, Manfred (Author) / Standfuss, Joerg (Author) / Weierstall, Uwe (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor)
Created2015-01-27
130270-Thumbnail Image.png
Description
X-ray diffraction patterns from two-dimensional (2-D) protein crystals obtained using femtosecond X-ray pulses from an X-ray free-electron laser (XFEL) are presented. To date, it has not been possible to acquire transmission X-ray diffraction patterns from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated

X-ray diffraction patterns from two-dimensional (2-D) protein crystals obtained using femtosecond X-ray pulses from an X-ray free-electron laser (XFEL) are presented. To date, it has not been possible to acquire transmission X-ray diffraction patterns from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permit a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy approach at the Linac Coherent Light Source, Bragg diffraction was acquired to better than 8.5 Å resolution for two different 2-D protein crystal samples each less than 10 nm thick and maintained at room temperature. These proof-of-principle results show promise for structural analysis of both soluble and membrane proteins arranged as 2-D crystals without requiring cryogenic conditions or the formation of three-dimensional crystals.
ContributorsFrank, Matthias (Author) / Carlson, David B. (Author) / Hunter, Mark S. (Author) / Williams, Garth J. (Author) / Messerschmidt, Marc (Author) / Zatsepin, Nadia (Author) / Barty, Anton (Author) / Benner, W. Henry (Author) / Chu, Kaiqin (Author) / Graf, Alexander T. (Author) / Hau-Riege, Stefan P. (Author) / Kirian, Richard A. (Author) / Padeste, Celestino (Author) / Pardini, Tommaso (Author) / Pedrini, Bill (Author) / Segelke, Brent (Author) / Seibert, M. Marvin (Author) / Spence, John (Author) / Tsai, Ching-Ju (Author) / Lane, Stephen M. (Author) / Li, Xiao-Dan (Author) / Schertler, Gebhard (Author) / Boutet, Sebastien (Author) / Coleman, Matthew (Author) / Evans, James E. (Author) / College of Liberal Arts and Sciences (Contributor) / Department of Physics (Contributor)
Created2014-02-28
127985-Thumbnail Image.png
Description

This paper describes a novel method for displaying data obtained by three-dimensional medical imaging, by which the position and orientation of a freely movable screen are optically tracked and used in real time to select the current slice from the data set for presentation. With this method, which we call

This paper describes a novel method for displaying data obtained by three-dimensional medical imaging, by which the position and orientation of a freely movable screen are optically tracked and used in real time to select the current slice from the data set for presentation. With this method, which we call a “freely moving in-situ medical image”, the screen and imaged data are registered to a common coordinate system in space external to the user, at adjustable scale, and are available for free exploration. The three-dimensional image data occupy empty space, as if an invisible patient is being sliced by the moving screen. A behavioral study using real computed tomography lung vessel data established the superiority of the in situ display over a control condition with the same free exploration, but displaying data on a fixed screen (ex situ), with respect to accuracy in the task of tracing along a vessel and reporting spatial relations between vessel structures. A “freely moving in-situ medical image” display appears from these measures to promote spatial navigation and understanding of medical data.

ContributorsShukla, Gaurav (Author) / Klatzky, Roberta L. (Author) / Wu, Bing (Author) / Wang, Bo (Author) / Galeotti, John (Author) / Chapmann, Brian (Author) / Stetten, George (Author) / New College of Interdisciplinary Arts and Sciences (Contributor)
Created2017-08-23
127988-Thumbnail Image.png
Description

Essential or enduring understandings are often defined as the underlying core concepts or “big ideas” we’d like our students to remember when much of the course content has been forgotten. The central dogma of molecular biology and how cellular information is stored, used, and conveyed is one of the essential

Essential or enduring understandings are often defined as the underlying core concepts or “big ideas” we’d like our students to remember when much of the course content has been forgotten. The central dogma of molecular biology and how cellular information is stored, used, and conveyed is one of the essential understandings students should retain after a course or unit in molecular biology or genetics. An additional enduring understanding is the relationships between DNA sequence, RNA sequence, mRNA production and processing, and the resulting polypeptide/protein product. A final big idea in molecular biology is the relationship between DNA mutation and polypeptide change. To engage students in these essential understandings in a Genetics course, I have developed a hands-on activity to simulate VDJ recombination. Students use a foldable type activity to splice out regions of a mock kappa light chain gene to generate a DNA sequence for transcription and translation. Students fold the activity several different times in multiple ways to “recombine” and generate several different DNA sequences. They then are asked to construct the corresponding mRNA and polypeptide sequence of each “recombined” DNA sequence and reflect on the products in a write-to-learn activity.

Created2017-08-11
127989-Thumbnail Image.png
Description

The elongases of very long chain fatty acid (ELOVL or ELO) are essential in the biosynthesis of fatty acids longer than C14. Here, two ELO full-length cDNAs (TmELO1, TmELO2) from the yellow mealworm (Tenebrio molitor L.) were isolated and the functions were characterized. The open reading frame (ORF) lengths of

The elongases of very long chain fatty acid (ELOVL or ELO) are essential in the biosynthesis of fatty acids longer than C14. Here, two ELO full-length cDNAs (TmELO1, TmELO2) from the yellow mealworm (Tenebrio molitor L.) were isolated and the functions were characterized. The open reading frame (ORF) lengths of TmELO1 and TmELO2 were 1005 bp and 972 bp, respectively and the corresponding peptide sequences each contained several conserved motifs including the histidine-box motif HXXHH. Phylogenetic analysis demonstrated high similarity with the ELO of Tribolium castaneum and Drosophila melanogaster. Both TmELO genes were expressed at various levels in eggs, 1st and 2nd instar larvae, mature larvae, pupae, male and female adults. Injection of dsTmELO1 but not dsTmELO2 RNA into mature larvae significantly increased mortality although RNAi did not produce any obvious changes in the fatty acid composition in the survivors. Heterologous expression of TmELO genes in yeast revealed that TmELO1 and TmELO2 function to synthesize long chain and very long chain fatty acids.

ContributorsZheng, Tianxiang (Author) / Li, Hongshuang (Author) / Han, Na (Author) / Wang, Shengyin (Author) / Hackney Price, Jennifer (Author) / Wang, Minzi (Author) / Zhang, Dayu (Author) / New College of Interdisciplinary Arts and Sciences (Contributor)
Created2017-09-08
127887-Thumbnail Image.png
Description

To investigate dual-process persuasion theories in the context of group decision making, we studied low and high need-for-cognition (NFC) participants within a mock trial study. Participants considered plaintiff and defense expert scientific testimony that varied in argument strength. All participants heard a cross-examination of the experts focusing on peripheral information

To investigate dual-process persuasion theories in the context of group decision making, we studied low and high need-for-cognition (NFC) participants within a mock trial study. Participants considered plaintiff and defense expert scientific testimony that varied in argument strength. All participants heard a cross-examination of the experts focusing on peripheral information (e.g., credentials) about the expert, but half were randomly assigned to also hear central information highlighting flaws in the expert’s message (e.g., quality of the research presented by the expert). Participants rendered pre- and post-group-deliberation verdicts, which were considered “scientifically accurate” if the verdicts reflected the strong (versus weak) expert message, and “scientifically inaccurate” if they reflected the weak (versus strong) expert message. For individual participants, we replicated studies testing classic persuasion theories: Factors promoting reliance on central information (i.e., central cross-examination, high NFC) improved verdict accuracy because they sensitized individual participants to the quality discrepancy between the experts’ messages. Interestingly, however, at the group level, the more that scientifically accurate mock jurors discussed peripheral (versus central) information about the experts, the more likely their group was to reach the scientifically accurate verdict. When participants were arguing for the scientifically accurate verdict consistent with the strong expert message, peripheral comments increased their persuasiveness, which made the group more likely to reach the more scientifically accurate verdict.

Created2017-09-20
127897-Thumbnail Image.png
Description

Specification of PM2.5 transmission characteristics is important for pollution control and policymaking. We apply higher-order organization of complex networks to identify major potential PM2.5 contributors and PM2.5 transport pathways of a network of 189 cities in China. The network we create in this paper consists of major cities in China

Specification of PM2.5 transmission characteristics is important for pollution control and policymaking. We apply higher-order organization of complex networks to identify major potential PM2.5 contributors and PM2.5 transport pathways of a network of 189 cities in China. The network we create in this paper consists of major cities in China and contains information on meteorological conditions of wind speed and wind direction, data on geographic distance, mountains, and PM2.5 concentrations. We aim to reveal PM2.5 mobility between cities in China. Two major conclusions are revealed through motif analysis of complex networks. First, major potential PM2.5 pollution contributors are identified for each cluster by one motif, which reflects movements from source to target. Second, transport pathways of PM2.5 are revealed by another motif, which reflects transmission routes. To our knowledge, this is the first work to apply higher-order network analysis to study PM2.5 transport.

ContributorsWang, Yufang (Author) / Wang, Haiyan (Author) / Chang, Shuhua (Author) / Liu, Maoxing (Author) / New College of Interdisciplinary Arts and Sciences (Contributor)
Created2017-10-16
127836-Thumbnail Image.png
Description

Previous proof-of-concept measurements on single-layer two-dimensional membrane-protein crystals performed at X-ray free-electron lasers (FELs) have demonstrated that the collection of meaningful diffraction patterns, which is not possible at synchrotrons because of radiation-damage issues, is feasible. Here, the results obtained from the analysis of a thousand single-shot, room-temperature X-ray FEL diffraction

Previous proof-of-concept measurements on single-layer two-dimensional membrane-protein crystals performed at X-ray free-electron lasers (FELs) have demonstrated that the collection of meaningful diffraction patterns, which is not possible at synchrotrons because of radiation-damage issues, is feasible. Here, the results obtained from the analysis of a thousand single-shot, room-temperature X-ray FEL diffraction images from two-dimensional crystals of a bacteriorhodopsin mutant are reported in detail. The high redundancy in the measurements boosts the intensity signal-to-noise ratio, so that the values of the diffracted intensities can be reliably determined down to the detector-edge resolution of 4 Å. The results show that two-dimensional serial crystallography at X-ray FELs is a suitable method to study membrane proteins to near-atomic length scales at ambient temperature. The method presented here can be extended to pump–probe studies of optically triggered structural changes on submillisecond timescales in two-dimensional crystals, which allow functionally relevant large-scale motions that may be quenched in three-dimensional crystals.

ContributorsCasadei, Cecilia M. (Author) / Tsai, Ching-Ju (Author) / Barty, Anton (Author) / Hunter, Mark S. (Author) / Zatsepin, Nadia (Author) / Padeste, Celestino (Author) / Capitani, Guido (Author) / Benner, W. Henry (Author) / Boutet, Sebastien (Author) / Hau-Riege, Stefan P. (Author) / Kupitz, Christopher (Author) / Messerschmidt, Marc (Author) / Ogren, John I. (Author) / Pardini, Tom (Author) / Rothschild, Kenneth J. (Author) / Sala, Leonardo (Author) / Segelke, Brent (Author) / Williams, Garth J. (Author) / Evans, James E. (Author) / Li, Xiao-Dan (Author) / Coleman, Matthew (Author) / Pedrini, Bill (Author) / Frank, Matthias (Author) / College of Liberal Arts and Sciences (Contributor)
Created2018-01