Molecular Weight Control of Curdlan (β-1,3-Glucan Polysaccharide) Provides Unique Polynucleotide Binding Properties

Abstract

ABSTRACT:Recently, we found that schizophyllan belonging to a -1,3-glucan polysaccharide family forms macromolecular complexes with certain single-stranded polynucleotides. The specific complex formation is originated from the -1,3-glucan skeleton in the main chain. In this paper, we have reported that curdlan, which is a -1,3-glucan polysaccharide without a side chain glucose unit, shows unique poly(C) binding properties different from those of schizophyllan; in the experiments using curdlan samples with the controlled molecular weight, the complexation ability appeared only in a limited ''M w range window''. Stoichiometric analysis revealed that the ''M w range window'' appears as a result of the competition between curdlan-curdlan self-association and curdlan-polynucleotide complexation. Furthermore, when the experiments were extended to other polynucleotides such as poly(A), poly(dA) and poly(dT), the ''M w range window'' also appeared at their characteristic molecular weights. We believe, therefore, that curdlan can be applicable, in spite of its cheapness, as a precious functional material to gene technology.

Removal of the side‐chain glucose groups from schizophyllan improves the thermal stability of the polycytidylic acid complexes under the physiological conditions

“…37 Before the complexation study, therefore, we estimated the molecular weight from gel permeation chromatography (GPC). As shown in Table II, the molecular weights of the modified SPG derivatives are between M w ϭ 107,000 and 141,000, where the thermal stability is scarcely different from that of unmodified SPG [SPG(33.3)].…”

Variable chain conformations of renatured β‐glucan in dimethylsulfoxide/water mixture

“…Thus, understanding the relationship between the chain conformation and the mechanism of immunological activities becomes more and more important for biologists and polymer scientists. Recent findings have demonstrated that the denatured triple helical β‐glucans including schizophyllan (SPG), scleroglucan, and curdlan can interact with homo‐polynucleotide to form a novel complex with two single chains of β‐glucan and one single homo‐polynucleotide by a combination of hydrogen‐bonding and hydrophobic interactions under physiological conditions 5–8. The creation of new helical macromolecular complex consisting of DNA or RNA and polynucleotide can be widely used in gene delivery system and gene therapy, and would be an exciting development 9–12.…”

The chemical and digestive properties of a soluble glucan from Agrobacterium sp. ZX09

“…The solubility of glucans in the media depends on their chemical structure, molecular mass and conformation (Colleoni-Sirghie, Fulton, & White, 2003). The sulfate and phosphate esters of curdlan (Koumoto et al, 2004) with increased water solubility, display enhanced biological activity (Toida, Chaidedgumjorn, & Linhardt, 2003) and, moreover, a water-soluble aminated curdlan derivative has tumorigenic properties (Seijelid, 1986).…”