Instrumentation Development on Multi-Scaled Scattering for Bio-Molecular Solution

点击翻译按钮获取中文摘要

DESCRIPTION (provided by applicant): The present proposal is aimed at incorporating the newly developed cross-correlation light scattering capability with synchrotron X-ray scattering, specifically designed for bio-macromolecular gels, solutions and suspensions. The combined X-rays and laser light scattering techniques will be able to detect structural variations and dynamics in a continuous and very broad spatial range (0.1 - 2000 nm), even in turbid media. Many bio-macromolecular fluids, when undergoing structure changes or chemical reactions as well as phase transitions, can become opaque. Then, multiple scattering becomes a serious problem, especially in the visible light wave length range. The cross-correlation technique can extract single-scattering information in relatively turbid media, with the dynamic cross-correlation function analysis yielding knowledge on diffusive and rotational motions of species and estimates of size distributions. Such information, when simultaneously combined with X-ray scattering and diffraction results, is not attainable by methods such as NMR or microscopy. The unique multiple-scaled scattering instrumentation for research and education of complex bio- macromolecular solutions will include the integration of wide-angle X-ray diffraction (WAXD, spatial resolution 0.1-2 nm), small-angle X-ray scattering (SAXS, spatial resolution 2-120 nm) and laser light scattering with cross-correlation (spatial resolution 5-2000 nm). Experiments will include in-vitro bio- mineralization in collagen, muscle extension, solution behavior of bio-macromolecular aggregations, e.g., amyloids - the Abeta42 peptide involved in Alzheimer's disease; peptides derived from fertilinD and cyritestin in fertilization. The proposed light-scattering instrumentation, including a "constant-concentration" flow cell (for bio-mineralization study) and a small-volume solution cell (for precious bio-materials), will be assembled and initially tested at Stony Brook, and then incorporated into the X27C beam line in the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL). The proposed instrumentation will be the first of its kind for combined laser light with cross-correlation and X-ray scattering research in the world. This instrumentation will provide new information, not accessible today, to several NIH projects described in this proposal; it will also be useful to many other NIH funded projects through general users of the X27C beamline.