“Autoreduction”—An unusual property of pure spinach cytochrome ƒ

Pure spinach cytochrome ƒ exhibits the anomalous property of autoreduction at physiological pH. After complete oxidation followed by removal of oxidant, about 80% of the cytochrome ƒ content appeared in reduced form without addition of exogenous reductant. The phenomenon was observed with two different buffers, two different oxidants, and three different methods of removing the oxidant.     

“Advanced Voice Function Assessment”—Goals and activities of COST Action 2103

The COST Action 2103 “Advanced Voice Function Assessment” is a joint initiative of speech processing teams (engineers and physicists) and the European Laryngological Research Group (ELRG) (laryngologists/phoniatricians). The Action officially started in December 2006, and is running till the end of 2010. 17 European countries are involved. A main objective is a better understanding of the relationship between biomechanical changes at the level of the vocal folds – as induced by pathology and tissue reaction to strain – and alterations of the acoustical voice signal. This needs to result in developing accurate, objective and clinically useful methods of investigation of voice quality in patients, and of strategies for preventing occupational voice disorders in professional speakers. Modelling is an essential tool in this process.     

Molybdenum EXAFS of the desulfovibrio gigas MO(2Fe-2S) protein—structural similarity to “desulfo” xanthine dehydrogenase

The molybdenum EXAFS of the Mo(2Fe-2S) protein from Desulfovibrio gigas has been examined using fluorescence detection and synchrotron radiation. In the oxidized form the molybdenum environment is found to contain two terminal oxo groups and two long (2.47 Å) Mo-S bonds. Evidence was also found for an oxygen or nitrogen donor ligand a 1.90 Å. Addition of dithionite to the oxidized enzyme results in loss of a terminal oxo group, perhaps due to protonation. In addition, a 0.1 Å contraction in the Mo-S bond lengths is observed. The behavior of both oxidized and dithionite-treated forms is similar to that observed previously with “desulfo” xanthine oxidase.