Purification and subunit determination of the nickel-dependent<i>Staphylococcus xylosus</i>urease

Abstract

The Staphylococcus xylosus C2a urease was purified 655-fold to a maximum specific activity of 1 573 U/mg and contained three non-identical subunits (64, 17.8 and 16.3 kDa). The purified urease had a total molecular mass of 300 kDa and contained 3.91 ± 0.1 g atoms nickel per molecule as determined by atomic absorption spectrometry. The maximum urease activity occurred at pH 7.2 and 65°C, with a pI between 4 and 5.