The influence of additives on the X-ray induced aggregation of malate synthase monitoring of the aggregation processin situ by time-resolved small-angle X-ray scattering

Zipper, Peter; Kriechbaum, Manfred; Wilfing, R.; Durchschlag, Helmut

doi:10.1007/bf00817892

Cited by 3 publications

(2 citation statements)

References 21 publications

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“…Cryocooling samples to 100 K has been shown to reduce radiation damage rates in SAXS (Meisburger et al, 2013;Hopkins et al, 2015), but substantial methodological development is required before cryocooling can be accepted for routine use. Despite the importance of radiation damage as a limiting factor in SAXS, early efforts using laboratory X-ray sources (Zipper & Durchschlag, 1980a,b,c, 1981Zipper et al, 1980Zipper et al, , 1985Zipper & Kriechbaum, 1986) have been followed by only two systematic, quantitative studies at synchrotron sources (Kuwamoto et al, 2004;Jeffries et al, 2015). With recent and planned upgrades to already bright third-generation sources and construction of high-brightness fourth-generation sources, understanding, quantifying and ultimately minimizing radiation damage in biological SAXS will be essential to efficient use and full exploitation of these sources.…”

Section: Introductionmentioning

confidence: 99%

Quantifying radiation damage in biomolecular small-angle X-ray scattering

Hopkins

Thorne

2016

J Appl Cryst

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Small-angle X-ray scattering (SAXS) is an increasingly popular technique that provides low-resolution structural information about biological macromolecules in solution. Many of the practical limitations of the technique, such as minimum required sample volume, and of experimental design, such as sample flow cells, are necessary because the biological samples are sensitive to damage from the X-rays. Radiation damage typically manifests as aggregation of the sample, which makes the collected data unreliable. However, there has been little systematic investigation of the most effective methods to reduce damage rates, and results from previous damage studies are not easily compared with results from other beamlines. Here a methodology is provided for quantifying radiation damage in SAXS to provide consistent results between different experiments, experimenters and beamlines. These methods are demonstrated on radiation damage data collected from lysozyme, glucose isomerase and xylanase, and it is found that no single metric is sufficient to describe radiation damage in SAXS for all samples. The radius of gyration, molecular weight and integrated SAXS profile intensity constitute a minimal set of parameters that capture all types of observed behavior. Radiation sensitivities derived from these parameters show a large protein dependence, varying by up to six orders of magnitude between the different proteins tested. This work should enable consistent reporting of radiation damage effects, allowing more systematic studies of the most effective minimization strategies.

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Section: Introductionmentioning

confidence: 99%

Quantifying radiation damage in biomolecular small-angle X-ray scattering

Hopkins

Thorne

2016

J Appl Cryst

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“…Earlier work on X-ray induced radiation damage − suggests that the indirect effects of radiation, i.e., the reaction of radical and nonradical products of water radiolysis with the protein, are mainly responsible for radiation damage. In our experiment, we cannot observe the effects of radicals, but the likely small (catalytic) changes in the side chain residues (UV spectra) may be indicative of such radical activities.…”

Section: Resultsmentioning

confidence: 99%

Combined SAXS/UV–vis/Raman as a Diagnostic and Structure Resolving Tool in Materials and Life Sciences Applications

2014

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In order to diagnose and fully correlate structural, chemical, and functional features of macromolecules and particles in solution, we propose the integration of spectroscopy and scattering on the same measuring volume and at the same time in a dedicated sample environment with multiple probes. Combined SAXS/UV-vis and SAXS/Raman information are employed to study the radiation damage effect in proteins in solution and the scattering from single wall carbon nanotubes (SWNTs) in SDS dispersion, respectively. In the first case, a clear correlation is observed between the time dependence of the radius of gyration (Rg) of the protein determined by SAXS and the turbidity of the protein solution extracted from simultaneous UV-vis measurements. In the second case, the ratio of bundled/isolated carbon nanotubes is obtained unambiguously through proper modeling of the scattering data and cross-validated with the Raman information. The uses of convex constraint analysis (CCA) and two-dimensional correlation analyses (2DCOS and 2DHCOS) are introduced to fully explore the combination of data sets from different techniques and to extract unique insights from the sample.

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Primary and post‐irradiation inactivation of the sulfhydryl enzyme malate synthase: correlation of protective effects of additives

Durchschlag

Zipper

1988

FEBS Letters

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The presence of additives during X-irradiation of malate synthase led to radioprotective effects against primary and postirradiation inactivation. Pronounced effects were provided by typical scavengers, sulthydryl reagents and specific ligands (substrates, products, analogues). The results show that scavenging and specific protection are responsible for the protective efficiency of additives. Scavengers delete noxious species formed during irradiation or post-radiationem. Sulthydryl reagents may act as repair substances. Specific ligands protect the active site of the enzyme and the essential sulthydryls; specific protection is more pronounced post-radiationem. Ligands and sulthydryl reagents may additionally act as scavengers. A cumulative index for the protective power of additives against both sorts of inactivation was established.

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The influence of additives on the X-ray induced aggregation of malate synthase monitoring of the aggregation processin situ by time-resolved small-angle X-ray scattering

Cited by 3 publications

References 21 publications

Quantifying radiation damage in biomolecular small-angle X-ray scattering

Quantifying radiation damage in biomolecular small-angle X-ray scattering

Combined SAXS/UV–vis/Raman as a Diagnostic and Structure Resolving Tool in Materials and Life Sciences Applications

Primary and post‐irradiation inactivation of the sulfhydryl enzyme malate synthase: correlation of protective effects of additives

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