The high-mosaicity illusion: Revealing the true physical characteristics of macromolecular crystals

Henry D. Bellamy, Edward H. Snell, Jeff Lovelace, Matthew Pokross, Gloria E.O. Borgstahl

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Typical measurements of macromolecular crystal mosaicity are dominated by the characteristics of the X-ray beam and as a result the mosaicity value given during data processing can be an artifact of the instrumentation rather than the sample. For physical characterization of crystals, an experimental system and software have been developed to simultaneously measure the diffraction resolution and mosaic spread of macromolecular crystals. The contributions of the X-ray beam to the reflection angular widths were minimized by using a highly parallel, highly monochromatic synchrotron source. Hundreds of reflection profiles over a wide resolution range were rapidly measured using a charge-coupled device (CCD) area detector in combination with superfine φ-slicing data collection. The Lorentz effect and beam contributions were evaluated and deconvoluted from the recorded data. Data collection and processing is described. From 1°of superfine φ-slice data collected on a crystal of manganese superoxide dismutase, the mosaicities of 260 reflections were measured. The average mosaicity was 0.0101° (s.d. 0.0035°) measured as the full-width at half-maximum (FWHM) and ranged from 0.0011 to 0.0188°. Each reflection profile was individually fitted with two Gaussian profiles, with the first Gaussian contributing 55% (s.d. 9%) and the second contributing 35% (s.d. 9%) of the reflection. On average, the deconvoluted width of the first Gaussian was 0.0054°(s.d. 0.0015°) and the second was 0.0061°(s.d. 0.0023°). The mosaicity of the crystal was anisotropic, with FWHM values of 0.0068, 0.0140 and 0.0046°along the a, b and c axes, respectively. The anisotropic mosaicity analysis indicates that the crystal is most perfect in the direction that corresponds to the favored growth direction of the crystal.

Original languageEnglish (US)
Pages (from-to)986-995
Number of pages10
JournalActa Crystallographica Section D: Biological Crystallography
Volume56
Issue number8
DOIs
StatePublished - Aug 29 2000

Fingerprint

illusions
X-Rays
Crystals
Synchrotrons
Crystallization
Artifacts
Superoxide Dismutase
crystals
Software
Equipment and Supplies
Full width at half maximum
profiles
X rays
slicing
inorganic peroxides
Direction compound
Charge coupled devices
artifacts
manganese
charge coupled devices

ASJC Scopus subject areas

  • Structural Biology

Cite this

The high-mosaicity illusion : Revealing the true physical characteristics of macromolecular crystals. / Bellamy, Henry D.; Snell, Edward H.; Lovelace, Jeff; Pokross, Matthew; Borgstahl, Gloria E.O.

In: Acta Crystallographica Section D: Biological Crystallography, Vol. 56, No. 8, 29.08.2000, p. 986-995.

Research output: Contribution to journalArticle

@article{5236c849cf1a40c985f12c35cc0fe0e7,
title = "The high-mosaicity illusion: Revealing the true physical characteristics of macromolecular crystals",
abstract = "Typical measurements of macromolecular crystal mosaicity are dominated by the characteristics of the X-ray beam and as a result the mosaicity value given during data processing can be an artifact of the instrumentation rather than the sample. For physical characterization of crystals, an experimental system and software have been developed to simultaneously measure the diffraction resolution and mosaic spread of macromolecular crystals. The contributions of the X-ray beam to the reflection angular widths were minimized by using a highly parallel, highly monochromatic synchrotron source. Hundreds of reflection profiles over a wide resolution range were rapidly measured using a charge-coupled device (CCD) area detector in combination with superfine φ-slicing data collection. The Lorentz effect and beam contributions were evaluated and deconvoluted from the recorded data. Data collection and processing is described. From 1°of superfine φ-slice data collected on a crystal of manganese superoxide dismutase, the mosaicities of 260 reflections were measured. The average mosaicity was 0.0101° (s.d. 0.0035°) measured as the full-width at half-maximum (FWHM) and ranged from 0.0011 to 0.0188°. Each reflection profile was individually fitted with two Gaussian profiles, with the first Gaussian contributing 55{\%} (s.d. 9{\%}) and the second contributing 35{\%} (s.d. 9{\%}) of the reflection. On average, the deconvoluted width of the first Gaussian was 0.0054°(s.d. 0.0015°) and the second was 0.0061°(s.d. 0.0023°). The mosaicity of the crystal was anisotropic, with FWHM values of 0.0068, 0.0140 and 0.0046°along the a, b and c axes, respectively. The anisotropic mosaicity analysis indicates that the crystal is most perfect in the direction that corresponds to the favored growth direction of the crystal.",
author = "Bellamy, {Henry D.} and Snell, {Edward H.} and Jeff Lovelace and Matthew Pokross and Borgstahl, {Gloria E.O.}",
year = "2000",
month = "8",
day = "29",
doi = "10.1107/S0907444900007356",
language = "English (US)",
volume = "56",
pages = "986--995",
journal = "Acta Crystallographica Section D: Structural Biology",
issn = "0907-4449",
publisher = "John Wiley and Sons Inc.",
number = "8",

}

TY - JOUR

T1 - The high-mosaicity illusion

T2 - Revealing the true physical characteristics of macromolecular crystals

AU - Bellamy, Henry D.

AU - Snell, Edward H.

AU - Lovelace, Jeff

AU - Pokross, Matthew

AU - Borgstahl, Gloria E.O.

PY - 2000/8/29

Y1 - 2000/8/29

N2 - Typical measurements of macromolecular crystal mosaicity are dominated by the characteristics of the X-ray beam and as a result the mosaicity value given during data processing can be an artifact of the instrumentation rather than the sample. For physical characterization of crystals, an experimental system and software have been developed to simultaneously measure the diffraction resolution and mosaic spread of macromolecular crystals. The contributions of the X-ray beam to the reflection angular widths were minimized by using a highly parallel, highly monochromatic synchrotron source. Hundreds of reflection profiles over a wide resolution range were rapidly measured using a charge-coupled device (CCD) area detector in combination with superfine φ-slicing data collection. The Lorentz effect and beam contributions were evaluated and deconvoluted from the recorded data. Data collection and processing is described. From 1°of superfine φ-slice data collected on a crystal of manganese superoxide dismutase, the mosaicities of 260 reflections were measured. The average mosaicity was 0.0101° (s.d. 0.0035°) measured as the full-width at half-maximum (FWHM) and ranged from 0.0011 to 0.0188°. Each reflection profile was individually fitted with two Gaussian profiles, with the first Gaussian contributing 55% (s.d. 9%) and the second contributing 35% (s.d. 9%) of the reflection. On average, the deconvoluted width of the first Gaussian was 0.0054°(s.d. 0.0015°) and the second was 0.0061°(s.d. 0.0023°). The mosaicity of the crystal was anisotropic, with FWHM values of 0.0068, 0.0140 and 0.0046°along the a, b and c axes, respectively. The anisotropic mosaicity analysis indicates that the crystal is most perfect in the direction that corresponds to the favored growth direction of the crystal.

AB - Typical measurements of macromolecular crystal mosaicity are dominated by the characteristics of the X-ray beam and as a result the mosaicity value given during data processing can be an artifact of the instrumentation rather than the sample. For physical characterization of crystals, an experimental system and software have been developed to simultaneously measure the diffraction resolution and mosaic spread of macromolecular crystals. The contributions of the X-ray beam to the reflection angular widths were minimized by using a highly parallel, highly monochromatic synchrotron source. Hundreds of reflection profiles over a wide resolution range were rapidly measured using a charge-coupled device (CCD) area detector in combination with superfine φ-slicing data collection. The Lorentz effect and beam contributions were evaluated and deconvoluted from the recorded data. Data collection and processing is described. From 1°of superfine φ-slice data collected on a crystal of manganese superoxide dismutase, the mosaicities of 260 reflections were measured. The average mosaicity was 0.0101° (s.d. 0.0035°) measured as the full-width at half-maximum (FWHM) and ranged from 0.0011 to 0.0188°. Each reflection profile was individually fitted with two Gaussian profiles, with the first Gaussian contributing 55% (s.d. 9%) and the second contributing 35% (s.d. 9%) of the reflection. On average, the deconvoluted width of the first Gaussian was 0.0054°(s.d. 0.0015°) and the second was 0.0061°(s.d. 0.0023°). The mosaicity of the crystal was anisotropic, with FWHM values of 0.0068, 0.0140 and 0.0046°along the a, b and c axes, respectively. The anisotropic mosaicity analysis indicates that the crystal is most perfect in the direction that corresponds to the favored growth direction of the crystal.

UR - http://www.scopus.com/inward/record.url?scp=0033883176&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033883176&partnerID=8YFLogxK

U2 - 10.1107/S0907444900007356

DO - 10.1107/S0907444900007356

M3 - Article

C2 - 10944335

AN - SCOPUS:0033883176

VL - 56

SP - 986

EP - 995

JO - Acta Crystallographica Section D: Structural Biology

JF - Acta Crystallographica Section D: Structural Biology

SN - 0907-4449

IS - 8

ER -