Inorganic pyrophosphatase--II. Purification and studies of some properties of the enzyme isolated from thermophylic bacterium Thermus flavus 70 K.

Inorganic pyrophosphatase was isolated from T. flavus in a homogeneous form with a specific activity of 400 U/mg. The enzyme has an isoelectric point 5.0 and consists of 4 subunits each of 24,000 mol. wt. Pyrophosphatase possesses high thermal stability. The enzyme can hydrolyze PPi, ATP and p-nitrophenylphosphate. Kinetic constants of the enzyme's interaction with the metal-activator and metal-substrate complex have been estimated.