Higher order structures of a bioactive, water-soluble (1a3)-[beta]-d-glucan derived from Saccharomyces cerevisiae

• Published in: Carbohydrate polymers 2013-02, Vol.92 (2), p.1026-1032
• Main Authors: Qin, Fen, Sletmoen, Marit, Stokke, Bjoern Torger, Christensen, Bjoern E
• Format: Article
• Language: English
• Subjects: Aggregation behavior; Carbohydrates; Cell walls; Hysteresis; Light scattering; Particulate matter; Saccharomyces cerevisiae; Size distribution; Wound healing
• ISSN: 0144-8617

Water-soluble (1a3)-[beta]-d-glucans with 1,6-linked branches (SBG), originally isolated from the cell walls of Saccharomyces cerevisiae and partially depolymerised to a weight average degree of polymerisation (DPw) in the range 120a160 for optimal performance in wound healing applications, were studied by dynamic light scattering (DLS), SEC MALLS and AFM. Results indicate that dilute aqueous SBG solutions (1 mu g/ml to 3 mg/ml) contain higher order structures with a very wide size distribution in water (10a500 nm), corresponding to a mixture of single chains, multi-chain aggregates including triple-stranded motifs, and particulate materials. The latter were enriched in longer chains compared to non-particulate fractions. The size distribution of SBG aggregates shifted to slightly lower values upon heating, but showed hysteresis upon cooling. AFM images prepared from very dilute aqueous solution (1a5 mu g/ml) analysis showed by comparison to other (1a3)-[beta]-d-glucans that some of the structures were the triple helical species coexisting with larger aggregates and single chains, in contrast to carboxymethylated SBG, which contained predominantly single chains. The ability to control the aggregation behaviour of SBG enables tailoring of the physical, and possibly bioactive, properties of SBG preparations.