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Maximizing Macromolecule Crystal Size for Neutron Diffraction ExperimentsA challenge in neutron diffraction experiments is growing large (greater than 1 cu mm) macromolecule crystals. In taking up this challenge we have used statistical experiment design techniques to quickly identify crystallization conditions under which the largest crystals grow. These techniques provide the maximum information for minimal experimental effort, allowing optimal screening of crystallization variables in a simple experimental matrix, using the minimum amount of sample. Analysis of the results quickly tells the investigator what conditions are the most important for the crystallization. These can then be used to maximize the crystallization results in terms of reducing crystal numbers and providing large crystals of suitable habit. We have used these techniques to grow large crystals of Glucose isomerase. Glucose isomerase is an industrial enzyme used extensively in the food industry for the conversion of glucose to fructose. The aim of this study is the elucidation of the enzymatic mechanism at the molecular level. The accurate determination of hydrogen positions, which is critical for this, is a requirement that neutron diffraction is uniquely suited for. Preliminary neutron diffraction experiments with these crystals conducted at the Institute Laue-Langevin (Grenoble, France) reveal diffraction to beyond 2.5 angstrom. Macromolecular crystal growth is a process involving many parameters, and statistical experimental design is naturally suited to this field. These techniques are sample independent and provide an experimental strategy to maximize crystal volume and habit for neutron diffraction studies.
Document ID
20020093117
Document Type
Conference Paper
Authors
Judge, R. A. (Universities Space Research Association Huntsville, AL United States)
Kephart, R. (Universities Space Research Association Huntsville, AL United States)
Leardi, R. (Dipartimento di Chimica e Tecnologie Genova Italy)
Myles, D. A. (European Molecular Biology Lab. Grenoble, France)
Snell, E. H. (Universities Space Research Association Huntsville, AL United States)
vanderWoerd, M. (Universities Space Research Association Huntsville, AL United States)
Curreri, Peter A.
Date Acquired
August 20, 2013
Publication Date
January 1, 2002
Subject Category
Solid-State Physics
Meeting Information
XIX Congress and General Assembly of the International Union of Crystallography(Geneva)
Funding Number(s)
CONTRACT_GRANT: NCC8-66
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.