Synchrotron Radiation as a Source for X-ray Diffraction

Rosenbaum, G.; Holmes, Kenneth C.; Witz, Jean‐François

doi:10.1038/230434a0

Cited by 192 publications

(81 citation statements)

References 9 publications

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“…The evidence for DESY is that H=8 mm and W=4 mm. (Rosenbaum, Holmes & Witz, 1971;Tuomi, Naukkarinen, Laurila & Rabe, 1973;Tuomi, Naukkarinen & Rabe, 1974), while for NINA H=0.5 mm (Beaumont & Hart, 1974) and the present work shows that W=0.5 ram. Unlike conventional X-ray diffraction topography with characteristic radiation, the whole source contributes to the intensity diffracted by each point in the sample.…”

Section: Resolutionmentioning

confidence: 75%

“…Because of betatron oscillations about the stable orbit the effective source size is larger than one might expect. For the X-ray region of the spectrum the effective source size is about 0.5 mm square for NINA (Beaumont & Hart, 1974) and 4 mm by 8 mm for DESY (Rosenbaum, Holmes & Witz, 1971). The effective source size from SPEAR should be less than either of these.…”

Section: The Source Characteristicsmentioning

confidence: 99%

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Synchrotron radiation – its application to high-speed, high-resolution X-ray diffraction topography

Hart¹

1975

J Appl Cryst

112

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With almost perfect silicon crystals and cleaved lithium fluoride crystals as extreme examples, the feasibility of using synchrotron radiation for X-ray diffraction topography has been investigated. In both spatial resolution and strain resolution the synchrotron source diffraction topographs are competitive with topographs obtained using conventional X-ray sources but exposure times are reduced from several hours per cm 2 to one second per cm 2 using standard recording techniques with llford nuclear emulsions. Contrary to (the author's) expectations, the instrumentation required is far simpler for synchrotron radiation than for conventional sources.

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Section: Resolutionmentioning

confidence: 75%

Section: The Source Characteristicsmentioning

confidence: 99%

Synchrotron radiation – its application to high-speed, high-resolution X-ray diffraction topography

Hart¹

1975

J Appl Cryst

112

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“…It is 40 y since the first synchrotron diffraction from insect muscle was recorded (13). Thanks to that pioneering work and subsequent improvements in synchrotron and X-ray detector technology, we were able to record real-time X-ray diffraction movies of stretch activation.…”

mentioning

confidence: 89%

X-ray diffraction evidence for myosin-troponin connections and tropomyosin movement during stretch activation of insect flight muscle

Edwards

Irving

Baumann

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

108

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Stretch activation is important in the mechanical properties of vertebrate cardiac muscle and essential to the flight muscles of most insects. Despite decades of investigation, the underlying molecular mechanism of stretch activation is unknown. We investigated the role of recently observed connections between myosin and troponin, called "troponin bridges," by analyzing real-time X-ray diffraction "movies" from sinusoidally stretch-activated Lethocerus muscles. Observed changes in X-ray reflections arising from myosin heads, actin filaments, troponin, and tropomyosin were consistent with the hypothesis that troponin bridges are the key agent of mechanical signal transduction. The time-resolved sequence of molecular changes suggests a mechanism for stretch activation, in which troponin bridges mechanically tug tropomyosin aside to relieve tropomyosin's steric blocking of myosin-actin binding. This enables subsequent force production, with crossbridge targeting further enhanced by stretch-induced lattice compression and thick-filament twisting. Similar linkages may operate in other muscle systems, such as mammalian cardiac muscle, where stretch activation is thought to aid in cardiac ejection.S tretch activation is a striking example of mechanical signal transduction, in which stretching a partially activated muscle yields, after a delay, greater activation. It is observed to varying degrees in all striated muscles, is prominent in vertebrate cardiac muscle where it may underlie the Frank-Starling relationship (1), and is essential to flight in multiple orders of insects, which together comprise ∼75% of insect species (2) and fully half of all animal taxa (3). Since stretch activation was first reported by Pringle (4), a great deal has been learned about how muscular contraction is driven by cyclic myosin-actin interactions (5) which, in vertebrate skeletal muscles, are controlled by calcium's effect on the steric blocking action of troponin-tropomyosin (6). However, even atomic resolution models of myosin-actin (7) and the troponin complex (8, 9) fail to shed any light on the mechanism of activation by stretch. The central question of stretch activation remains: How does mechanical stress convert to myosinactin activation while the requisite [Ca 2þ ] stays constant?Recently we observed cross-bridges between thick (mainly myosin) filaments and thin (mainly actin-troponin-tropomyosin) filaments at the level of the troponin (10). These myosin-troponin connections, referred to here simply as troponin bridges, comprised about 15% of all cross-bridges identified in an insect flight muscle (IFM) quick frozen during an isometric contraction. Troponin bridges represent a newly recognized class of crossbridges, distinct from the "traditional" force-generating myosin cross-bridges that bind to actin target zones halfway between troponins in IFM (10, 11). The direct observation of troponin bridges revived a previously speculative mechanism for stretch activation (12), in which troponin bridges serve as the agent of mechanica...

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“…In 1970, the first experimental use of SR in biology was made by Rosenbaum, Witz and Holmes at the Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany, where it was shown that diffraction from a muscle fibre could be recorded with very much shorter exposure times than with a laboratory-based X-ray source (Rosenbaum et al 1971). From that time, the special brightness of SR began to be appreciated for MX.…”

Section: Introduction-early Historymentioning

confidence: 99%

Macromolecular crystallography at synchrotron radiation sources: current status and future developments

Duke

Johnson

2010

Proc. R. Soc. A.

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X-ray diffraction with synchrotron radiation (SR) has revealed the atomic structures of numerous biological macromolecules including proteins and protein complexes, nucleic acids and their protein complexes, viruses, membrane proteins and drug targets. The bright SR X-ray beam with its small divergence has made the study of weakly diffracting crystals of large biological molecules possible. The ability to tune the wavelength of the SR beam to the absorption edge of certain elements has allowed anomalous scattering to be exploited for phase determination. We review the developments at synchrotron sources and beamlines from the early days to the present time, and discuss the significance of the results in providing a deeper understanding of the biological function, the design of new therapeutic molecules and time-resolved studies of dynamic events using pump-probe techniques. Radiation damage, a problem with bright X-ray sources, has been partially alleviated by collecting data at low temperature (100 K) but work is ongoing. In the most recent development, free electron laser sources can offer a peak brightness of hard X-rays approximately 10 8 times brighter than that achieved at SR sources. We describe briefly how early experiments at FLASH and Linear Coherent Light Source have shown exciting possibilities for the future.

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Synchrotron Radiation as a Source for X-ray Diffraction

Abstract: Some preliminary results have been obtained with synchrotron radiation from the 7.5 GeV electron synchrotron Deutsches Elektronen - Synchrotron (DESY) in Hamburg as a source for X-ray diffraction

Cited by 192 publications

References 9 publications

Synchrotron radiation – its application to high-speed, high-resolution X-ray diffraction topography

Synchrotron radiation – its application to high-speed, high-resolution X-ray diffraction topography

X-ray diffraction evidence for myosin-troponin connections and tropomyosin movement during stretch activation of insect flight muscle

Macromolecular crystallography at synchrotron radiation sources: current status and future developments

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