Controlled stability of the triple-stranded helical structure of a beta-1,3-glucan with a chromophoric aromatic moiety at a peripheral position.
We synthesized a semiartificial beta-1,3-glucan, curdlan with dialkylaniline groups (CUR-DA), that bears chromophoric aromatic groups at its peripheral positions. Spectroscopic studies as well as microscopic observations indicate that CUR-DA adopts a triple-stranded helical structure in water- or methanol-rich solutions of dimethyl sulfoxide (DMSO). This triple-stranded helical structure exhibits high thermal stability and resistance to base, attributes that are similar to those of the triple-stranded helical structure of native beta-1,3-glucans such as schizophyllan. Moreover, we found that the stability of the triple-stranded helical structure can be easily modulated by solvent composition and metal-ion (Zn2+) binding. As beta-1,3-glucan polysaccharides are known to serve as "polymeric" hosts, including certain DNA molecules, carbon nanotubes, and conjugated polymers, and complexation occurs only with the single-stranded structure, this information is very useful for the creation of these attractive polymeric composites, the controlled release of DNA, and so on.
Ikeda
Masato
M
Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan.
Haraguchi
Shuichi
S
Numata
Munenori
M
Shinkai
Seiji
S
D002942:Circular Dichroism; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008968:Molecular Conformation; D013056:Spectrophotometry, Ultraviolet; D015032:Zinc / Q000737:chemistry; D047071:beta-Glucans / Q000138:chemical synthesis / Q000737:chemistry*
D007477:Ions; D047071:beta-Glucans; C038459:curdlan; C033363:beta-1,3-glucan; D015032:Zinc; D004121:Dimethyl Sulfoxide