Electroanalytical determination of tungsten and molybdenum in proteins

Recent crystal structure determinations accelerated the progress in the bio chemistry of tungsten-containing enzymes. In order to characterize these en zymes, a sensitive determination of this metal in protein-containing sample s is necessary. An electroanalytical tungsten determination has successfull y been adapted to determine the tungsten and molybdenum content in enzymes. The tungsten and molybdenum content can be measured simultaneously from 1 to 10 mug of purified protein with little or no sample handling. More crude protein samples require precipitation of interfering surface active materi al with 10% perchloric acid. This method affords the isolation of novel mol ybdenum and tungsten-containing proteins via molybdenum and tungsten monito ring of column fractions, without using radioactive isotopes. A screening o f soluble proteins from Pyrococcus furiosus for tungsten, using anion-excha nge column chromatography to separate the proteins, has been performed. The three known tungsten-containing enzymes from P. furiosus were recovered wi th this screening. (C) 2001 Academic Press.