Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

SQUASH - combining constraints for macromolecular phase refinement and extension.

K Y Zhang1

  • 1Molecular Biology Institute and Department of Chemistry and Biochemistry, University of California at Los Angeles, 90024-1570, USA.

Acta Crystallographica. Section D, Biological Crystallography
|January 1, 1993
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Effects of oleic acid supplementation on ileal fatty acid digestibility, intestinal barrier function, and cecal microbiota in Pekin ducks fed a high-fat diet.

Poultry science·2026
Same author

Effects of different blending ratios of lard and chicken fat on growth performance, nutrient utilization, serum lipid metabolism, and tissue fatty acid composition in meat ducks.

Poultry science·2026
Same author

[The influence of two-way referral model on treatment and prognosis of patients with chronic heart failure].

Zhonghua xin xue guan bing za zhi·2025
Same author

New Limits on Ultralight Axionlike Dark Matter from Reanalyzed Data.

Physical review letters·2025
Same author

Effects of dietary supplementation with oleic acid on growth performance, dietary fat utilization, serum and intestinal lipid metabolic parameters, and enterocyte lipid droplet metabolism in Pekin ducks.

Poultry science·2025
Same author

Effects of different dietary vitamin D combinations during the grower phase and the feed restriction phase on growth performance and sternal morphology, mineralization, and related genes expression of bone metabolism in Pekin ducks.

Poultry science·2023

This study presents an integrated method for improving macromolecular phase refinement and extension using electron density constraints. The synergistic approach enhances phase accuracy, as demonstrated with 2Zn insulin data.

Area of Science:

  • Crystallography
  • Structural Biology
  • Biophysics

Background:

  • Macromolecular crystallography is crucial for determining the 3D structures of biological molecules.
  • Phase determination remains a significant challenge in macromolecular crystallography.
  • Accurate phase information is essential for reconstructing electron density maps.

Purpose of the Study:

  • To develop an integrated procedure for macromolecular phase refinement and extension.
  • To simultaneously satisfy constraints on electron density distribution, solvent flatness, local shape, and molecular symmetry.
  • To improve the accuracy and reliability of crystallographic phase estimates.

Main Methods:

  • Combined electron density constraints (distribution, solvent flatness, local shape, molecular symmetry) into a single procedure.

Related Experiment Videos

  • Solved a system of non-linear equations to satisfy electron density constraints simultaneously.
  • Filtered electron density solutions using a phase combination procedure.
  • Refined non-crystallographic symmetry operations via rotation/translation search and least-squares minimization.

    • Main Results:

    • Demonstrated synergistic effects of combined constraints in improving macromolecular phases.
    • Successfully refined and extended phases using the integrated procedure.
    • Validated the method on 2Zn insulin crystal data, showing improved phase accuracy.
    • Reduced systematic phase errors during averaging through refined symmetry operations.

    Conclusions:

    • The integrated procedure effectively refines and extends macromolecular phases.
    • Simultaneous application of electron density constraints leads to synergistic improvements.
    • The method offers a robust approach to address phase determination challenges in crystallography.
    • Accurate phase refinement is critical for high-resolution structural analysis.