Structure and dynamics of biomolecules studied by Mossbauer spectroscopy

Mossbauer spectroscopy not only offers information about the Astructural and electronic properties of iron centres in biomolecules but also about their Adynamic behaviour. In order to apply this nuclear method to biologically relevant iron centres Aknowledge of nuclear and molecular physics is required. This review introduces the basic Aphysical concepts of 57FeMossbauer spectroscopy. The various oxidation and spin states of iron Aare discussed in a simple orbital frame. Aspects of the ligand field theory of paramagnetic Amolecules are introduced, and areview covering the iron centres in proteins which have been Apresently characterized is given. The review covers Mossbauer studies starting from heme proteins, Acontinuing with the abovementioned proteins containing di-nuclear iron clusters, iron storage Aproteins and iron-sulfur proteins, and concludes with the complex iron clusters of nitrogenase. AThe physical properties of the different forms of iron centres as well as their biological Arelevance are elaborated upon. The effects of electronic spin dynamics on the Mossbauer spectra are Areviewed. In addition, the dynamics of the iron ion itself and how it can be studied by AMossbauer spectroscopy is discussed. An introduction into the recently developed technique using Asynchroton radiation which is also called Mossbauer spectroscopy in the time domain shall Agive an impression about the future developments in this field of spectroscopy.