β-1,3-D-glucan schizophyllan/poly(dA) triple-helical complex in dilute solution

Area of Science:

• Biopolymers
• Supramolecular Chemistry
• Materials Science

Background:

• Schizophyllan (SPG) is a β-1,3-D-glucan with a unique triple helix structure.
• Poly(deoxyadenylic acid) (dA) is a synthetic DNA polymer.
• Understanding biopolymer complexation is crucial for developing novel materials.

Purpose of the Study:

• To investigate the formation and properties of a novel complex between poly(deoxyadenylic acid) (dA) and schizophyllan (SPG).
• To characterize the structural and conformational changes upon complexation.
• To determine the impact of complexation on chain flexibility and dimensions.

Main Methods:

• Dilute solution property measurements using light scattering and small-angle X-ray scattering.
• Intrinsic viscosity measurements.
• Analysis using the wormlike cylinder model.

Main Results:

• A novel complex of poly(deoxyadenylic acid) (dA) and schizophyllan (SPG) was formed with a specific stoichiometric ratio.
• The dA/SPG complex exhibits semiflexible rod-like behavior without branching or cross-linking.
• Complexation significantly reduced chain flexibility (to 25% for dA/SPG and 15% for S-dA/SPG) and elongated the helix.

Conclusions:

• Poly(deoxyadenylic acid) (dA) forms a stable, rod-like complex with schizophyllan (SPG).
• Complexation induces significant stiffening and axial elongation of the polymer chains.
• This study provides insights into DNA-polysaccharide interactions and their structural consequences.