Invertases of Lilium Pollen

Abstract

Two different forms of invertase are found in pollen of lily (L. auratum). One form is cytoplasmic (invertase 1), and the other is bound to the pollen wall (invertase 2). Invertase 1 was partially purified and is a glycoprotein (apparent MW, 450 kilodaltons) with a Km of 0.65 mM for sucrose. The 2 invertases differ in pH optimum and thermal stability. Invertases of lily pollen are .beta.-fructofuranosidases which can hydrolyze sucrose but not melizitose. The mature pollen grains have enzyme activity in both cytoplasmic and wall fractions, and no increase in the activity of either occurs during germiantion. The wall-bound enzyme could not be released by treatments with detergents or high salt concentrations.