Spectrum of Urease Isozymes: Genetic, Polymeric and Conformeric

IT is now becoming obvious that the simple view of urease structure and function, current for half a century 1 , is inadequate. The enzyme is not absolutely specific for urea, and it has at least two additional substrates, hydroxyurea 2 and dihydroxyurea 3 . Kinetic isotope data indicate multiple substrate sites that not only interact but also interconvert 4 , and multiple molecular forms have been frequently demonstrated by analytic ultracentrifugation and gel filtration techniques 5 . So far, however, the multiple forms have not been shown to be enzymatically active.