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

Abstract

We have firstly demonstrated the renaturation process of dissociated single chains of lentinan (s-LNT) and the variable conformations of the renatured LNT (r-LNT). The results from ultrasensitive differential scanning calorimetry and circular dichroism revealed that the variable structures including perfect triple helix, defective triple helix containing duplex segment, and single chains occurred in the renaturation of s-LNT, depending on the renaturation time, solvent composition, molecular weight, and the mode of renaturation. When water was added into s-LNT/dimethylsulfoxide (DMSO) to reach 95% (v/v), the classic low-temperature intra-triple-helical conformational transition at ∼10(°) C (T(1)) appeared within 4 h, indicative of a rapid reconstruction of triple helical structure. Besides, one newly endothermic peak at ∼43(°) C (T(2)) simultaneously occurred, which was first ascribed to the melting of duplex segment in the imperfect triplex. The duplex stretches disappeared when DMSO reached 50%, in which single chains coexisted with triplex. Moreover, the duplex segment disappeared by slowly dropping water into s-LNT/DMSO. This work suggested that the structure of r-LNT could be controllable, and provided important information for their successful development and application in polymer and life science.

Relative Stability of the Scleroglucan Triple-Helix and Single Strand: an Insight from Computational and Experimental Techniques

“…It is known that the Sclg triplex is stable in water solution up to 135 ∘ C. Furthermore, triplex stability decreases by adding DMSO to the water solution, or by increasing the alkalinity, with a triplex unfolding observed close to pH 13 [6][7][8]. Very similar behaviours have been reported for other (1 → 3)--Dglucans with 1,6-linked branches, from a structural point of view, closely related with Sclg [9][10][11][12]. The reversibility of the triplex to ss-Sclg transition is still under discussion; however, in many experimental conditions, the native triplex does not form again after a denaturation process occurred [13][14][15].…”

Orally Delivered Antisense Oligodeoxyribonucleotides of TNF‐α via Polysaccharide‐Based Nanocomposites Targeting Intestinal Inflammation

“…It has been reported that the triple helical structure broken by DMSO can be reconstructed by adding into plenty of water . The reconstructed triple helical LNT was denoted as r‐LNT.…”

“…Of these, lentinan (LNT for short) has been demonstrated to exist as a triple helix (denoted t‐LNT) in water and as a single flexible chain (denoted s‐LNT) under such conditions as in dimethyl sulfoxide (DMSO), in aqueous sodium hydroxide (NaOH) solution with the NaOH concentration higher than 0.08 m , and in water at the temperature of higher than 135 °C . When the DMSO content decreases gradually through adding water or dialysis against water, the s‐LNT chains reassemble into the triple helix (denoted r‐LNT) owing to the hydrophobic and hydrogen bonding interactions . Moreover, when single polydeoxyadenylic acid (poly(dA)) chains are added during the reassembling process of s‐LNT, two s‐LNT chains are able to selectively combine a poly(dA) chain via hydrogen bonding to form a novel triple helical hybrid (denoted s‐LNT/poly(dA)) with high thermal stability under the physiological condition, effectively protecting poly(dA) from degradation.…”

A novel gene carrier prepared from triple helical β-glucan and polydeoxyadenylic acid

“…[29][30][31] Due to the strong hydrogen bonding interaction, the s-LNT chains can be reassociated into the triple helix upon changing the DMSO content or pH value to achieve suitable conditions. 32,33 Furthermore, s-LNT can be used to stabilize and disperse metal nanoparticles such as Au and Ag nanoparticles because of strong hydrophobic and hydrogen bonding interactions. 34,35 More interestingly, two chains of s-LNT are able to selectively combine single polydeoxyadenylic acid (poly(dA)) via hydrogen bonds to form a novel triple helical complex with high thermal stability under physiological conditions, 36 which effectively protects poly(dA) from enzyme degradation.…”