Helix-breaking news: fighting crystalline starch energy deposits in the cell

Abstract

Starch is the major component for providing energy storage for plants. However in the cell, starch occurs in semicrystalline granules of various sizes depending on the plant species. Therefore, it is important to understand how crystalline starch becomes metabolically available. Recent studies provide insight into the structural basis of how rare phosphate esters present in starch granules can stimulate its degradation in the cell. Phosphorylation at the C-3 position of the glucose units seems to play a significant role by inducing strain in crystalline starch and resulting in helix unfolding. These findings add a new perspective on how plants increase bioavailability of this carbohydrate matrix through a phosphate-induced amorphisation mechanism.