LSD logo

Life Sciences Division
1997-98
Progress Report

Contents

Foreword

Division

  • Overview
  • Mission
  • Structure

Systems Biology

Technology Applications

Infrastructure

Partnerships

Initiatives

Appendices

LSD Home Page

Structural Biology

The proposed Center for Structural Molecular Biology (CSMB) is intended to bring together the existing strengths at ORNL in neutron sciences, mass spectrometry, and computational biology and make them available to a broad user community in the biological sciences. The cornerstone of the CSMB is a small angle neutron scattering (SANS) facility to be constructed at the HFIR at ORNL. SANS is an important tool for studying molecular conformations and molecular interactions. It provides insight into the molecular basis of communication pathways that achieve coordinated function by identifying specific chemical groups that interact with the environment and with molecular networks involved in binding and activation sequences. It provides information on the dynamics of a biomolecule in solution and complements the high-resolution structural x-ray crystallographic data obtained from a static, crystalline molecule. SANS will be a key tool for understanding the cellular level communication that is the basis for protein and, thus, gene function.

Establishing the CSMB at this time is particularly critical because we can take advantage of a recently initiated upgrade at the HFIR. As part of this upgrade, the "brightest" long-wavelength neutron source in the U.S. is being constructed. During this upgrade, we have the opportunity to design and build a SANS instrument (and associated resources) specifically designed for the study of biological systems. This instrument will incorporate both high flux and a large area (1m2) detector to collect data over a wider solid angle to enhance the study of biological molecules. The resulting facility will provide the biological community in the U.S. with state-of-the-art capabilities in SANS, which will rival the world's best biological facilities at the Institut Laue Langevin (ILL) in France.

In addition to the SANS facility, we will incorporate well-established biological mass spectrometry and computational resources into the CSMB, providing the biological community with additional tools that would complement structural information obtained from SANS. As an example, it has been shown that modifications to proteins can effect both the structure and function of these biomolecules (e.g., Trewhella and co-workers, Biochem. 28, 2220-2228, 1989). Mass spectrometry can provide information on both the extent of these modifications and the sites of attachment. Computational modeling can support conformational changes observed in SANS data. In addition, for uncharacterized proteins, computational methods can be used to identify fold families and build models from related known proteins prior to SANS analysis. Capabilities within the CSMB would also complement resources at other structural biology facilities, such as synchrotron x-ray crystallography centers, to provide a more thorough picture of the structure of biological molecules and their interactions in complex systems. The proposed CSMB would provide structural capabilities to programs within the DOE community, and to other government, academic, and industrial laboratories. An advisory panel of distinguished scientists has been established to provide guidance to the Director and staff of the CSMB in the establishment of the center. A CSMB User Group consisting of potential users of the center will be created to give advice on equipment and capabilities to be included in the CSMB and to establish guidelines for the operation of the Center. An important aspect of the CSMB will be the training and education of students and scientists in the technologies within the CSMB. A wide range of opportunities for scientists and students working in the field of structural biology will be provided, including extended visits for experimental work, short courses, workshops, and scientific meetings.

Specific Features of the CSMB

  • SANS facilities to be built at the upgraded HFIR will be specifically designed for high flux and located as far away as possible from other instruments to achieve the low background required for biological studies. Adjacent laboratory facilities will be available for final preparation of samples. Data acquisition/reduction capabilities will be integrated into instrument. ORNL staff will be available to support users.
  • Additional existing neutron-based tools at HFIR will also be made available to the CSMB users, including another SANS instrument designed for studying materials with higher resolution and a reflectometer that can be used to study biomolecular monolayers and thin films. A small angle x-ray scattering (SAXS) instrument is also available at ORNL, which can be used to evaluate biological samples prior to SANS experiments.
  • Existing resources in biological mass spectrometry will be made available to the users of the CSMB, including two Fourier transform in cyclotron resonance mass spectrometers and a number of other instruments equipped with electrospray and matrix assisted laser desorption sources. Dedicated staff will support users.
  • Existing resources in computational biology/informatics will be made accessible to the users of the CSMB for modeling, prediction, and data base use, with dedicated staff to support users.
  • Sample preparation facilities to support SANS and MS experiments will be maintained with dedicated staff.
  • CSMB users will have access to the Joint Institute for Neutron Sciences (JINS) facility being built at ORNL during their visits. The JINS will include overnight accommodations, food facilities, offices, meeting space, etc.

Benefits to Structural Biology User Community

The proposed Center fills an important niche in the spectrum of scientific tools required to perform comprehensive structure - function experiments. It is designed with specific interfaces to the neutron crystallography center at LANL so as to jointly serve and grow the structural biology community that takes advantage of the unique features of neutron sources. It is unique in its combination of high-flux cold neutrons for SANS with a world-class computational biology resource, and pioneering mass spectrometry facility.