Spectrometer System for Investigation of Biological Molecules with Synchrotron Radiation at Wavelengths Greater Than 125 NM

摘要

The SUPERB experiment at the SURF II storage ring uses synchrotron radiation as a source of uv photons to measure circular dichroism (CD) of biological molecules. Conventional CD instruments are limited by the lack of stable laboratory continuum sources capable of providing large photon fluxes shortward of 200 nm. Synchrotron radiation overcomes these limitations and enables one to extend CD measurements down to the limit of the window transmission cutoff, which is 125 nm for CaF sub 2 used in the present configuration. Some molecules of biophysical interest, DNA and proteins for example, exhibit large CD effects below 200 nm, which reflect specific molecular conformations. CD is a sensitivie probe of molecular structure and enables us to learn how these molecules behave under various external conditions. In the future we plan to increase the measurement capabilities of SUPERB to include magnetic circular dichroism, fluorescence spectroscopy, and fluorescence lifetime measurements. (ERA citation 05:038802)