NDPase (GDPase, UDPase, ADPase) Assay Kit

A simple and reliable method for measuring NDPase activity in sub-cellular fractions based on the detection of the inorganic phosphate released from NDP by the appropriate NDPase. The color formation, measured at 700 nm in the presence of molybdate, is proportional to the amount of the inorganic phosphate released by enzymes.

GDPases/UDPases (NDPases) in yeasts are located exclusively in the Golgi complex and are a convenient marker for Golgi detection. NDPs are degraded to NMPs by nucleoside diphosphatase (GDPase/UDPase). The NMPs are then used in antiport transport of new nucleotide sugars into the organelle lumen. ADPases are known to be expressed on the cell plasma membrane (endothelial cells and vascular precursors) where they participate in nucleotide metabolism.

The kit was tested on rat tissue extracts (liver, kidney, spleen, and heart) and on a yeast (S. cerevisae) extract. It was also tested with microsomal fractions prepared from rat tissues and cell lines.

1 unit of NDPase releases 1 μmole of inorganic phosphate per minute at 25 °C under conditions specified by the assay.