A new sensitive, thiol tolerant method for the determination of inorganic pyrophosphatase.

In this work a new sensitive, thiol tolerant method for the determination of inorganic pyrophosphatase (EC 3.6.1.1) was developed. It is based on the formation of phosphomolybdate-triethylamine complex, which in acid-acetone mixture forms a white, homogeneous precipitate, the turbidity of which can accurately measured spectrophotometrically at 355 nm. This method can be easily applied to all the Pi-producing enzymes whose substrates are stable enough in our acidic experimental conditions.