Inorganic pyrophosphatase from pollen of Typha latifolia

An inorganic pyrophosphatase was purified about 3,800-fold from the pollen of Typha latifolia by chromatography on DEAE-Sephadex A-50, isoelectric focusing and gel filtration through Sephadex G-75. The enzyme had an optimum pH between 8.5-9.5 and required Mg(2+). Since an excess of pyrophosphate over Mg(2+) inhibited the pyrophosphatase reaction, the actual substrate may have been an Mg-pyrophosphate complex. The enzyme degraded inorganic pyrophosphate specifically, showing a Km value of 7.6 × 10(-5) m. A possible role of pyrophosphatase was discussed in connection with starch-sucrose conversion.