Facile preparation of highly crystalline lamellae of (1 → 3)-β-d-glucan using an extract of Euglena gracilis

In vitro synthesis of (1 → 3)-β-d-glucan was performed using laminaribiose phosphorylase obtained by an extraction of Euglena gracilis with sucrose phosphorylase. The synthetic product was a linear (1 → 3)-β-d-glucan with a narrow distribution of degree of polymerization (DP) centered on DP = 30. X-ray diffraction and electron microscopy revealed that the glucan molecules obtained were self-organized as highly crystalline hexagonal lamellae. This synthetic product has quite high structural homogeneity at every level from primary to higher-order structure, which is a great advantage for the detailed analyses of physiological functions of (1 → 3)-β-d-glucan.