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R Mullinger

Publications and source records attributed to R Mullinger.

4 recordsLinked to original sources
PubMed1976

Spin lattice relaxation and exchange interaction in a 2-iron, 2-sulphur protein.

A two-iron-two-sulphur non-haem iron protein, the ferredoxin from Spirulina maxima, has been studied by means of electron paramagnetic resonance (EPR) in the range where the spectrum loses resolution with increasing temperature. The spin-lattice relaxation times were deduced from linewidths measured by spectral simulation and their variation as a function of temperature is interpreted in terms of an Orbach mechanism. On this basis, the exchange integral between the two iron atoms, assuming as antiferromagnetic interaction between them, is estimated to be - 83 cm-1.

Computers↗
PubMed1975

The iron electron-nuclear double resonance (ENDOR) of 4-Fe clusters in iron-sulfur proteins from Chromatium and Clostridium pasteurianum.

Iron electron-nuclear double resonance (ENDOR) measurements were made of the 4-Fe clusters in oxidized Chromatium high-potential iron-sulfur protein, dithionite-reduced high-potential iron-sulfur protein in 80% dimethylsulphoxide, fully reduced Clostridium pasteurianum ferredoxin in aqueous solution and in 80% dimethylsulfoxide. The hyperfine couplings determined show that: i) the electron distribution in each case is nearly symmetric; ii) there are two types of iron in oxidized high potential iron-sulfur protein; iii) only one type of iron is observed in each fully reduced 4-Fe cluster; iv) the data also suggest a greater electron delocalization onto the ligands as compared to the 2-Fe ferredoxins.

Bacterial Proteins↗