The facility

The MCD spectrometer was built in collaboration with Lastek Pty Ltd. and is based on a high through-put / high resolution Jobin Yvon 750s monochromator and an Oxford Instruments SpectroMag superconducting magnet. A number of different light sources, detectors and gratings makes the instrument very versatile, with a wavelength range of 220 – 3000 nm.  The spectra can be measured between 1.6 – 300 K in magnetic fields of +/- 7.0 Tesla.  The facility is one of only two in Australia and especially targets the study of the structure and function of metalloproteins.

Applications

MCD spectroscopy is particularly suitable to the study of transition metal centres where there is a component of unquenched angular momentum. It is used to determine the electronic structure of metal centres, and the coordination/geometry of the metal environment. This makes it a powerful tool in the study of the active sites of metallo-proteins.

The technique is enhanced at low temperatures and high magnetic fields. An analysis of the temperature/magnetic field dependence. It is possible to gain polarised spectroscopic information from an non-oriented sample (ie a solution/glass)

Types of experiment

Variable temperature/ variable field. Circular Dichroism. Linear Dichroism. Polarimetry.

Sample requirements

Samples are usually measured as a frozen solution of an isotropic glass. Glycerol (50%) can be used as a glassing agent for aqueous solutions of proteins. Volumes of 50 – 200 mL are required. For non-aqueous systems other glasses such as ethanol/methanol, dichloromethane/DMF can be used.

Contacts

Dr Mark Riley,
Email: m.riley@uq.edu.au telephone: +61 7 336 53932

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