Ice in biomolecular cryocrystallography

open access..

Diffraction data acquired from cryocooled protein crystals often include diffraction from ice. Analysis of ice diffraction from crystals of three proteins shows that the ice formed within solvent cavities during rapid cooling is comprised of a stacking-disordered mixture of hexagonal and cubic planes, with the cubic plane fraction increasing with increasing cryoprotectant concentration and increasing cooling rate. Building on the work of Thorn and coworkers [Thorn et al. (2017), Acta Cryst. D73, 729-727], a revised metric is defined for detecting ice from deposited protein structure-factor data, and this metric is validated using full-frame diffraction data from the Integrated Resource for Reproducibility in Macromolecular Crystallography. Using this revised metric and improved algorithms, an analysis of structure-factor data from a random sample of 89 827 PDB entries collected at cryogenic temperatures indicates that roughly 16% show evidence of ice contamination, and that this fraction increases with increasing solvent content and maximum solvent-cavity size. By examining the ice diffraction-peak positions at which structure-factor perturbations are observed, it is found that roughly 25% of crystals exhibit ice with primarily hexagonal character, indicating that inadequate cooling rates and/or cryoprotectant concentrations were used, while the remaining 75% show ice with a stacking-disordered or cubic character.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:77

Enthalten in:

Acta crystallographica. Section D, Structural biology - 77(2021), Pt 4 vom: 01. Apr., Seite 540-554

Sprache:

Englisch

Beteiligte Personen:

Moreau, David W [VerfasserIn]
Atakisi, Hakan [VerfasserIn]
Thorne, Robert E [VerfasserIn]

Links:

Volltext

Themen:

Cryoprotective Agents
Ice
Journal Article
Macromolecular Substances
Protein crystallography
Proteins
Stacking disorder
Structure-factor error

Anmerkungen:

Date Completed 27.10.2021

Date Revised 11.11.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1107/S2059798321001170

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM323810055